Poster Session I

Poster Session I

Thursday, January 27,1994 10: 30 a. m. -12: 00 p. m.

Pavilion 9- 11

CATEGORIES

Maternal/Fetal Physiology

Antepartum Fetal Testing

Placental Physiology

POSTER NUMBERS

79-136

137-155

156-164

Judges:

Nancy A. Callan, MD

Frank A. Chervenak, MD

E. Albert Reece, N(D

Volume 170, Number 1, Part 2 Am j Obstet Gynecol

79 FETAL BREATIUNG CHARACTERISTICS AND POSTNATAL OUTCOME IN CASES OF CONGENITAL DIAPHRAGMATIC HERNIA. H. E. Fox, SS Badalian, C R. Chao, I. E. Timor-Tritsch, C. J. H. Stolar" Dept. Ob/Gyn and Pediatric Surgery, Columbia University, New York, NY. OBJECTIVE: To determine characteristics of fetal breathing activity by recording fetal nasal fluid flow velocity in cases of congenital diaphragmatic hernia (CDH) STUDY DESIGN: Records of fetal perinasal flow velocity were obtained in 45

cases at 34-41 weeks of gestation: in 14 cases of antenatally diagnosed CDH, and in 31 cases of uncomplicated pregnancy The records were made using a Toshiba SSA-140A or SSA-270 ultrasound system applying color-flow and spectral Doppler analysis. The average of 25 breath cycles from each case were determined for each of the following timing parameters: time of inspiration (TJ, time of expiration (T. ). breath-to-breath interval (T, +), and ratio of T, and T. (T, /r. ) RESULTS: The postnatal outcome of the 14 cases with CDH. one stillbirth and five neonatal deaths (group I), eight survived and were discharged (group 11) Values are mean ±SEM

Parameters Normal Group I Group 11 ANOVA P

T,,, (mscc) 1184.1+36.2 1288 6±59.2 1068.0±72 20 1206

T, (mace) 544.7+19.7 614.6±40.7 546.8±43 20 3688

T. (mace) 633.6±18.4 632.4±37 ? 493.2±34 3° 00039

T, rT, 0.86±0,021 0.98±0.05 1,12±0.05° 0.0001

For " vs P<0.05 by Student- Newman- eu s post hoc test CONCLUSIONS: Observation of fetal-breathing related nasal fluid flow velocity in cases of antenatally diagnosed CDH provides a rationale for hypothesis that T.

and T, IT. may be useful in the prediction of postnatal outcome. We speculate that the changes in the group of survivors may represent a compensatory phenomenon by causing intermittent changes in the volume of fluid within the lungs

80 FETAL BREATHING-RELATED NASAL FLUID FLOW CHARACTERISTICS IN PATIENTS WITH MATERNAL HYPERGLYCEMIA S. S Badalian', L. Baxi, C. R Chao, HE Fox Dept Ob/Gyn, Columbia University, New York, NY. OBJECTIVE: To determine the characteristics of fetal breathing-related

nasal fluid flow in pregnancies complicated by diabetes mellitus and hyperglycemia. STUDY DESIGN: Fetal breathing-related nasal fluid flow velocity waveforms were recorded using a Toshiba SSA-140A ultrasound system combined with color-flow and spectral Doppler analysis Recordings were made in 65 women at 30-41 weeks of gestation. In 37 cases, pregnancy was uncomplicated, in 11 cases pregnancy was complicated by Type I diabetes

mellitus; and in 17 cases, pregnancy was complicated by gestational diabetes. The subjects were classified into 3 groups by gestational age. 30-33 weeks, 34-37 weeks, and 38-41 weeks. Maternal hyperglycemia was defined as a plasma glucose value ranging from 140 to 205 mgs per 100 ml. A

continuous videotape record of the spectral Doppler imaging of fluid flow

velocity in the nose was made during each study session. Based on a sample of 25 consecutive fetal breaths, the timing components of breath cycles were determined: time of inspiration (T), time of expiration (T, ), breath-to-breath interval (T,, ), and ratio of T. and T. (TjT ). RESULTS: No relationship was found between the value of maternal blood

glucose and either fetal Tý (r==0.003), or T, /T, ratio (r'=0.0001). There

was a statistically significant difference to T, (mate) at 34-37 weeks gestation (P=0 040) in the cases of diabetes mellitus with maternal hyperglycemia (467±23 S. E. M. ) and uncomplicated pregnancy with maternal normal carbohydrate intolerance (560±28). There was a similar tendency in the values of T, (465± 19 and 517±20 respectively) at 38-41 weeks gestation CONCLUSIONS: Maternal hyperglycemia in cases of diabetes mellitus shortened the duration of the inspiratory phase of fetal breath cycle after 34

weeks of gestation. This difference may be related to previously demonstrated differences in other breathing parameters between the normal and hyperglycemic human fetus

SPO Abstracts 301

81 NATURAL OCCURRING INSULIN AUTOANTIBODIES IN NEONATES OF NORMAL PREGNANCIES.

S. Wellikx, K Berkowitz, M. de Veciana, M. Morgan. E. ArquillaX Dept. of Pathology and Ob/Gyn, Univ. of California, Irvine, CA.

OBJECTIVE: To determine if insulin autoantibodies (IAA) are present in neonatal cord blood from normal pregnancies, and whether these antibody levels correlate with maternal IAA and/or insulin levels and neonatal cord blood insulin levels. STUDY DESIGN: This was descriptive case series of paired neonatal cord and maternal blood samples taken from 20 random normal patients at delivery. Measurements of serum IAA (radio binding assay) and insulin (radiotmmune inhibition assay) were performed. Multiple linear regression and paired t-test were used for data analysis. RESULTS: No association was observed between neonatal IAA and maternal IAA levels, not were neonatal IAA levels associated with maternal insulin levels (r=0.05 and 0.3 respectively). Neonatal IAA levels (4.8 ± 3.2 pg/ml) were significantly higher than their respective maternal IAA levels (1.6 ± 2.5 pg/ml) (P< 0.005) and positively correlated with neonatal insulin levels (r=0.76, P<0001) In addition, neonatal insulin levels strongly correlated with neonatal birthweight (r=0.63. P<0.01). CONCLUSIONS: MAA are measurable in neonatal circulation at birth and are present in significantly higher concentrations than in their respective mothers Since neonatal IAA are so strongly associated with neonatal insulin, but not with maternal IAA or insulin, it seems unlikely that maternal IAA contribute significantly to IAA levels in fetal circulation These observations suggest that IAA

may be intrinsic to the fetal insulin immune tolerance system, and their effect on insulin bioavailability in the fetus may influence

neonatal birthweight.

82 TUMOR NECROSIS FACTOR-0 IS ELEVATED IN MATERNAL PLASMA BUT UNDETECTED IN AMNIOTIC FLUID IN THE SECOND TRIMESTER. M. J. Kuoforminc, A. M. Festamen, T. R. Wigton, R. K. Tamura, K. A. Rehnberg`, M. L. Socol, Dept. Ob/Gyn, Northwestern Univ., Chicago, IL. OBJECTIVE: To investigate the cellular arm of the immune system in the adaptation to pregnancy by assessing plasma and amniotic fluid levels

of the cytokins tumor necrosis factor-a (TNF-a). STUDY DESIGN: Forty-six healthy pregnant women (group A) who underwent second trimester genetic amniocentesis at a mean gestational age of 17.0± 1.6 weeks composed the study group. Blood was drawn from each patient prior to amniocentesis and on aliquot of amniotic fluid

was obtained for this study. Twenty-three healthy, non-pregnant women of reproductive age (group B), composed the control group and blood

was drawn from each participant. All specimens were stored and collectively assayed for TNF-o bye specific enzyme-linked snmunosseay. RESULTS: The mean age of patients in both groups was 34 years. In

group A, 16 patients were pnmigrevid and 30 patients were muhugrevtd. All patients had a normal karyotype and uneventful pregnancy. TNF-o

was detected in the plasma of 42/46 191 %) pregnant patients as compared to only 1 of 23 women (4%) in group B (p <. 0001). The

median plasma TNF-a level for group A was 174 pglmf (range 0-626

pg/ml). TNF-a was not detected in any of the amniotic fluid specimens siudied. CONCLUSIONS: Elevated levels of TNF-a were found in the plasma but

not the amniotic fluid of normal pregnant patients in the second trimester. This increase in plasma concentration of TNF-o compared to non pregnant control patients suggests involvement of the cellular branch of the immune system in the adaptation of the mother to the fetal allograft. Given its known capacity to limit trophoblast proliferation, TNF-a may be important in preventing exposure of fetal antigens to the maternal circulation. The inability to detect TNF-a in midtnmestar amniotic fluid implies that the most likely source of TNF-o is systemic macrophages or lymphocytes rather than those located at the maternal fetal interface.

302 SPO Abstracts

83 BODY COIPOSITION AND FAT DISTRIBUTION IN INFANTS OF WOMEN WITH NOR AL AND ABNORMAL GLUCOSE TOLERANCE. P. M. Catalano, A. Thomas', M. M. Dragox, S. B. Aminix. Dept. Reproductive Biology, Metrokeelth Ned Ctr., Case Western Reserve University, Cleveland, ON. 00.1ECTIVE: To assess body compos iti on and anthropomet ric measurements in infants of women with normal glucose tolerance (CTL) and gestational diabetes (GOM). We hypothesized that women with GDM had infants with increased and central distribution of body fat (F). STUDY DESIGN: 183 infants (CTL-102 and GDM-81) had total body electrical conductivity (TOBEC) estimates of body composition and anthropometric measurements at birth. Demographic data was obtained at the time of birth. Statistical analysis was performed using t- tests, chi-square analysis and analysis of covariance (ANCOVA). RENTS: The GDM were significantly (man ! ad) older (28.9 « 6.6 vs 26.5 + 5.6 yrs, p. 009), shorter (161.8 +_ 6.1 vs 164.8 ! 7.1 cm, p. 002) and heavier pregravid (79.5 + 23.3 vs 65.4 + 15.8 kB, p-. 0001) as compared with CTL. There were no significant differences in race, wt gain dur i nB gestation, parity, smok i nB status or paternal ht and wt. Gestational age at delivery was CTL 39.2 ! 1.2 vs GDM 38.2 ! 1.5 weeks, p-. 0001). There were no significant differences in neonatal sex, birthweight (BY), length, fat free mess (FFM) or head and abdominal circumference between groups. The GDM infants had greater %F (12.9 + 5.0 vs 10.9 + 4.8, p. 006) and F soss (453 ± 231 vs 382 ± 213 gm, p. 03) as compared with CTL. Skinfold measurements (triceps (TR), subscapular (S), flank (FL), thigh(T) and abdomen (A)) were all greater in the GDM (p. 0001) and had a more central distribution (TR+T/S+FL+A, p. 007) as compared with CTL. After adjusting for significant confounding factors using ANCOVA, the GDM had significantly greater BW (p. 04), F (p. 03) and %F (p. 01) but no significant difference in FFM as compared with CTL. CONCLUSIONS: Infants of women with GDM have significantly greater BY, F, %F and central distribution of F but no difference in FFM in casperison with CTL. These finding may have longterm implications regarding obesity and the deve l opment of di abetes ae lli tus in infants of GDM. Weight Watchers Foundation and MIN 22965.

84 FACTORS AFFECTING FETAL ITN AID BODY COB'OSITION. P. Catalano, M. Dragox, S. Aslnix. Dept. Ob/Gyn, Univ. of Vt. and Dept. of Reproductive Biol., Case Western Reserve Univ., Cleveland ON. OBJECTIVE: To correlate welt recognized factors affecting fetal growth and maternal carbohydrate metabolism with neonatal birthweight (BY) and body composition. We hypothesized that genetic factors primarily affected fat free soss (FFM) and maternal environment affected fetal fat (F) accretion. STUDY DESIGN: 188 singleton infants of healthy non-smoking women had wt and anthropcmetrie estimates of body composition performed within 24 hours of birth. independent variables obtained were: (1) Maternal ht, preyravid wt. body sass index (BMI), wt gain during gestation, education, aye and parity, (2) paternal ht, wt and Bill, (3) neonatal sex and gestational age (EGA). Additionally, 16 women (6 control and 10 gestational diabetes) had insulin sensitivity estimated using the glucose clamp technique. Stepwise regression analysis was used to correlate independent variables with BY, LBM and F. RENTS: Males had a significantly (p". 009) greater BW (mean + ad) vs females (3643 " 468 vs 3467 " 433 4s) as well as length (51.8 " 1.9 vs 50.7 + 1.9 cm, p.. 0002), head circumference (35.5 + 1.1 vs 34.9 + 1.1 CO. p=. 0001) and LBM (3157 ! 350 vs 2952 + 330 ps, p-. 0001) but no differe9ce in F (486 ! 201 ve 515 ± 189 pe, p". 32). 29 of the variance Jr- ". 29) in BW was scc( yted for by (EGA (r2=. 10), wt gain Cr . 06), pregravid wt Cr -. 05), "tat sex Cr =. 04) and parity 2(r -. 04)]; 39% of the varianci Cr . 30) in FFM by (("tat sex Cr -. 08), EGA ( -. 09), wt gain (r ". 06), pregravid wt (r =. 04) and paternal ht (r =. 03)] and 17% of the variance (r2=. 17) in F by [(parity r2". 08), EGA (r2'. 04), pregravid wt Cr =. 02), wt go In Cr -. 02) andneonatal sex Cr =. 01)]. Adding insulin sansitivity2 as a factor improved the correlations significantly. The total r for BY, FFM and F were 52%, 57% and 46%, respectively. COICL. L 10S: Neonatal sex, a genetic factor, had the greatest correlation with FFM and maternal parity which we speculate affects maternal metabolic environment had the strongest correlation with F. Including Insulin sensitivity as a factor improved the correlations 2 fold for LBM and 3 fold for F. NIN 22965.

January 1994 Am J Obstet Gynecol

85 REGKXAL BL000 FLOW DIKING SEVERE UMB4JCAL CORD OCCLUSION. F; H Ball. Jf Parer, LE Caldumelx J Johremx CM, and Dept of Cb1Gyn and RS, and Anesthesia, UCSF, San Francisco, CA 06ECTIVE: We have previously presented data at to meet g, demo statng fiat sews asphyxia produced by uterine artery (UtA) occlusion leads to organ blood flow (BF) redstribon, with pdaable changes in metaboaen. We wished to test our nut hypothesis tr t unbTral cad (UC) occlusion would podre a simiar pattern STUDY DESIGN: Six pregnant ewes at 0S of gestation were stxgically prepared with fetal vascular catheters, ECoG. EKG and EMG electrodes, and an inflatable cuff-type UC ocduder The fetuses were studied after 2 to 3 days of recovery Follow ng control measurements of regional BF (radoactts ns ospheres), FFR BP, blood gases, and acid base factors, the UC was progressively occluded until the fetal ECoG vies wo-electric Oockiron was nairleiied tar 90 mna. Further regional BF measuresrente were perbmied at 30,60, end 90 mine of occlusion and 30 min of recosy Statistical anatyslie Nos by ANGVA and Sb udent Neu r4(auts teat Stated dlfamnms wee signicant at P<0.05. RESULTS: Umbilical artery BF feil to 20±5% (meant SEM) of control by 60 nine and remained as und release. The fetal ECoG became hic by Bt1.5 mos. Over tie 90 mit period of ocdson tw pH tel tan 7.37: 001 to 6 821003, and BE tom 511 b-22s2 mEgl PC02 rose tam 55±2 b 96±7" ByABG perameters the asplyne was mae garere than nor UTA piepaakns. Fetal BP and FR paranef s undatiert angle changes at the Ism of occlusion but then shabiliaed at control values. Heart and gut BF did not derge. Bran and ade al BF more than dabled CVO, spleen. Wily and carcass BF fall to < 30%of contra 02 delivery to the brain and atenals rose, fell to the spleen, guf, Wheys and earpss, erd did not change to the heart CONCLUSIONS The letal response to as ihyxa of sin-Aar severity, as delemiiied by add base changes and ECoG suppression, appears to depend an the mecharssn producing tie insult. With UTA occlusion, the placenta and fetus are exposed to hypowa, and we have shown that cardiac BF rises, as does atrenal BF With UC occlusion only the fetus is imposed to deceased 02 deNvery The umbilical various 02 content w be nomu l but the bNA be decreased In to case owrdao blood km does not change. and rrportanüy CW falls (stale with UtA). We speculate that the heart is exposed to delelle sous diarges in pre- and ake-loK wir UC occlusion. and that Ihfs may preclude it tan responding appiopriealy to the" with increased 02 delivery, demote a notmal venous 02 content This may wrply that severe acute cord occlusion can have a damaging effect on cardiac function although redistribution of organ BF is otherwise appropriate and send r to that seen with lesser hypoxic msut

86 AN EVALUATION OF TYMPANIC THERMOMETRY IN AN OBSTETRIC POPULATION. D. Skundd, A. SonnenWidt, W. Wagw , F. Chervenak. Div. of MFM, Cornell Univ. Med. Ctr.. New York, NY. OBJECTIVE In an obstetric population, we set out to establish normal temperature ranges and reproducibil ity lr core temperatures measured by the tympanic thermometer, compare these core temperatures to oral electronic temperatures, and determine the tympanic thermometer's accuracy In recording fever. STUDY DESIGN: Simultaneous tympanic core temperatures and oral electronic temperatures were measured In obstetric Inpatients and outpatients, on a labor floor, during antepartum testing, and on a postpartum floor (73 patients). Repeat measurementswere taken 10 minutes later. RESULTS: Tympanic core temperatures were significantly higher than oral temperatures (p<0.00001), with means for the two groups of 37.76 degrees Centigrade (°C) and 38.95'C respectively. Both thermometers showed equivalent reproducibility between the Mal and repeat measurements, with Pearson's correlation coefficients of 0.98 for tympanic temperatures and 0.97 for oral temperatures. Using a predetermined level of 38.0°C oral for the definition of fever, we found the sensitivity, specficity, positive predictive value (PPV), and negative predictive value (NPV) to be 100%, 93%, 75%, and 100% respectively. CONCLUSIONS: 1) Normal temperature ranges for a population of obstetric patients for the tympanic thermometer are demonstrated. 2) Tympanic thermometer measurements In the normal rangewere shown to be as reproducible as oral electronic measurements. 3) The mean tympanic temperature was significantly higher, byan average of 0.81 'C, than the mean oral temperature. 4) Acceptable sensltlvtty, specificity. PPV, and NPV for the diagnosis of over were obtained using the tympanic thermometer.


87 CONTROL OF BEHAVIORAL STATE ORGANIZATION IN NORMAL HUMAN FETUSES. Groom , LS Bentz!, KP Singh'. University of South Alabama, Mobile; University of Alabama, Birmingham. OBJECTIVE: Repeated alterations in quiet sleep (QS) and active sleep (AS) is a basic feature of behavioral state organization in human fetuses. Activation of the reticular formation (RF) is important in the transition QS AS, and intrinsic changes in central nervous system activity (CNS) govern RF activation. Vibroacoustic stimulation (VAS) can alter RF activation and thus delay the occurrence of QS. Hypothesis: If intrinsic RF activation in human fetuses is

greatest just after entering AS and lowest just after entering QS, then fetuses

ought to be in an active period longer following VAS just after entering AS then following VAS closer to an AS-QS transition. We wanted to test this hypothesis. STUDY DESIGN: We examined 87 normal human fetuses at 37-41 weeks. QS

and AS were identified by the fetal heart rate pattern and the presence or absence of fetal eye and gross body movement. Each fetus was observed to enter AS before randomization. After remaining in AS for 3 min, the fetus either was not stimulated (N-30), received a single I-sec VAS after 3-5 min of AS (N-30), or received a single I-sec VAS after 44-46 min of AS (N-27). The study was terminated when the fetus either entered QS and remained in QS for 3 min or did

not return to QS within 60 min. RESULTS: Fetuses stimulated after 3-5 min of AS behaved similarly to fetuses

who had entered AS spontaneously. However, fetuses stimulated after 44-46 min of AS remained in an active period for a shorter length of time than fetuses who either had been in AS for 3-5 min before VAS (19.6 min vs 36.4 min, p =0.0001) or had entered AS spontaneously (19.6 min vs 44.2 min, p =0.0001). When we included our results on state organization following VAS delivered in QS [Early Hum Develop 33 (1993) 21-71, we found that VAS near a spontaneous AS-QS transition elicited a significantly different behavioral response than VAS

near a spontaneous QS-. AS transition: regardless of whether fetuses were in AS or QS at the time of stimulation, fetuses who were stimulated in close proximity to an AS-. QS transition returned to QS sooner than fetuses who were stimulated closer to a QS-. AS transition (18.7 min vs 37.2 min, p-0.0001). CONCLUSION: This is the first study to demonstrate that the developing CNS

places strict requirements on the amount of AS and QS during fetal life.

88 VAGAL TONE IN NORMAL TERM FETUSES DURING QUIET SLEEP. roome DM Mooney', LS Bentz', 7D Wilson'. University of South Alabama,

Mobile-, University of Arkansas, Little Rock. OBJECTIVE: High-frequency, rhythmic fluctuations in heart period are mediated mostly by changes in vagsl activity during respiration. Considerable

success has been achieved in neonates, infants, and older children using parasympathetic or vagal tone (V) as a marker for individual differences in central nervous system activity. We wanted to determine the relationship between V during breathing and V in the absence of respiratory activity in human fetuses during quiet sleep (QS). STUDY DESIGN: We examined 13 normal human fetuses between 36 and 40 weeks. QS was defined by a low-variability heart rue pattern and no fetal eye or grow body movement. Fetal breathing was monitored continuously using real. time ultrasound. The fetal electrocardiogram was captured transabdominally in 3-min blocks at a rate of 833 Hz and fetal R-waves were extracted using adaptive signal processing. Fetal R-wave interbeat intervals (IBI) were converted to equally spaced, time-based data and the low-frequency component was removed by filtering the weighted 1B1 files in the time domain using a 21-point third-order moving polynomial. Amplitudes of the power densities were summed over the frequency of spontaneous fetal breathing (0.3-1.3 Hz) and the natural logarithm

was taken to produce a single value, V. RESULTS: 45 3-min blocks (mean 3.5, range 1-8) were collected during periods of breathing and 36 3-min blocks (me8n 2.8, range 1-6) were collected during periods of non-breathing. Fetal breathing was associated with an approximately 25% increase in V at compared to non-breathing (3.25±0.43

versus 2.57±0.47, p-0.0001). When each fetus was examined separately, the mean V during breathing was always larger than the corresponding value in the absence of breathing. Furthermore, a significant linear relationship was found between the mean single-fetus V during spontaneous respiration and the mean single-fetus V during normally occurring apneic periods (r-0.772, p-0.002). CONCLUSION: Fetal breathing is associated with a significant increase in V.

and the linear relationship between V for periods of breathing and non-breathing implicates a central component in the genesis of respiratory sinus arrhythmia.

SPO Abstracts 303

89 MVALMA21OW or PERIPHERAL IRRVN BTLal. AXION IN ASSESSING PATIMT RESPONSE TO INTRIVLNOD8 Mg804 TMMhFT. DJ area, MD, LD Devoe, MD, Dept OSCYN, Mad Coll Ceorgia, Auqusta GA OBJZCTZVZsTo correlate maternal responses to peripheral nerve stimulation (PNS) with standard clinical and laboratory assessment for effects of parenteral (IV) MgSO4 therapy. STUDY DEBIGNtW* studied 10 gravidas with preterm labor (GA&26-34 wks) and 10 with preeclampsia (GAt26-41 wks). All received IV MgSO4 4gm bolus injections followed by 2gm/hr continuous infusions. A Paragraph- programmable peripheral nerve stimulator (Utah Medical Company) was et at a 30 milliamp current to stimulate the ulnar nerve. Ratios of 4th to lot twitch responses (T4) were determined along with serum Mg and Ca" levels and patellar reflexes (DTRS), before therapy and at hourly intervals for 4 hours subsequently. T4 ratios, serum Mg" levels and DTRa were correlated with repeated measures ANOVA or simple and multiple regressions. RNSULTSC Both groups were similar for all measurements; their data were pooled for all analyses. Serum Mg levels peaked and reached a steady state after 1 hour (4.6 t 0.4 (SD) mg/dl); there were no changes in serum Ca" levels over time. DTRa decreased with time(p -. 04). Mg levels were negatively correlated with DTRs(r - -. 33, p -. 08) T4 ratios had no significant changes with time or correlations with Mg' levels or DTRs. CONCLUSIONS: MgSO4 therapy exerts an inhibitory effect on DTRs, even at the lower and of "therapeutic range, " that was not adequately reflected by PNS responses. PNS responses of patients varied unpredictably once steady- state serum Mg levels were attained. The use of PNS, in this setting, appears less reliable than clinical DTRz for monitoring effects of MgSO 4 administration.

90 POTENTIAL ROUTE FOR FETAL THERAPY: INTRAMEMBRANOUS ABSORPTION OF INTRAAMNIOTICALLY INJECTED FUROSEMIDE. WM Gilbert, P. S. Newman', R. A. Brace'. Div. of Perinetology, Dept. of Repro. Med., Univ. of CA, San Diego. OBJECTIVE: To determine whether intraamniotically injected furo-

semide could be absorbed directly into total circulation via the ovine intremembranous pathway. STUDY DESIGN: 6 intact fetal sheep (previously presented) and 4

with legated esophagi were studied for 7 hours on two consecutive days. Day one was a control day. On day two, 15 mg of furosemide

was injected into the amniotic cavity after a one hour control period. RESULTS: On day two, intact fetuses (Figure, closed circles) demon-

strated a rapid and prolonged increase in unne flow (P < 0.0001)

as did the legated fetuses (open circles. P<0.0011 when compared to control day fetuses (crosses). Sodium and chloride excretion in-

creased significantly in intact (Na-691 3 220 (SE(% and CI-783 t 295%) and ligated fetuses 1.2 (Na-234 ± 70% and CI- 409 ± 74%). 1.0 CONCLUSIONS: Furose- E

ende, injected into the E8

ovine amniotic cavity, 3 .6

caused a rapid and pro- 0 longed fetal diuresis in spite

- .4

W of the inability to swallow, z demonstrating absorption

2

of furosemide via the 0 intramembranous pathway, a potential avenue for fetal '2.1 012345 therapy in the future. TIME (hr)

304 SPO Abstracts

91 AMNIOTIC FLUID AMINO ACIDS IN FETAL GROWTH RETARDATION I. M. Bernstein, S. Rhodes', and W. S. Stirewalt' Dept Ob/Gyn, Univ. of VT., Burl., VT. OBJECTIVE Changes characteristic of chronic starvation have been identified in the amino acid content of fetal and neonatal cord blood of growth retarded offspring. We hypothesized that these changes in amino acid patterns, specifically an increase in the glycine/valine ratio, would be present in the amniotic fluid of growth retarded fetuses. STUDY DESIGN Amniotic fluids from 63 pregnancies in the third trimester (range 33-39 wks) were examined. Twenty five pregnancies were complicated by fetal growth retardation (FGR) which was suspected by ultrasound and confirmed at birth. Amniocenteses were performed for routine clinical indications. Amino acid analysis was performed by HPLC. The glycine /valine ratio in amniotic fluid as a function of gestational age was compared between groups (FGR vs Control) by analysis of covariance. RESULTS Within the control (C) group, there was no difference in the mean value or the elope of the regression when infants of diabetic mothers (n=14) were compared to other controls (n=24). FGR demonstrated a significantly higher mean glycine/valine ratio than C (FGR 3.25+0.15 ve C 2.54±0.12, adjusted mean±S. E. p<0.001) but no difference in regression slope. CONCLUSION Amniotic fluid glycine/valine ratios are elevated in growth retarded fetuses. We speculate that these patterns may assist in the identification of the substrate deprived, growth retarded fetus.

. January 1994

Ani ,J

Obstes Gvnecol

93 AUTOMATIC DETECTION OF BREATHING MOVEMENTS BY POWER SPECTRUM DENSITY ANALYSIS OF FETAL HEART RATE. E FerrazzP, L Ghisoni, MG Signorim, S CenAti, and G Pardi Dept Ob/Gyn, ISBM San Paolo Univ Milan, Dept Elctronics Poktechmc of Milan, Italy OBJECTIVE Power spectrum density (PSD) analysis of fetal heart rate variability (HRV) derived from abdominal fetal ECG tracings, was applied to investigate the correlations between fetal heart rate and behavioural states, detected by real time uttrasonography STUDY DESIGN: Fetal ECG signal was recorded by abdominal leads in 20 normal fetuses Analog to digital conversion was performed at IODDHz sampling rate, 12 bit precision Simultaneous ultrasonic observation of fetal behavioural state was performed Algorithms were developed to identify and subtract maternal ORS and noise Interval tachograms, constituted by the R-R- duration values, were obtained for both maternal and fetal tracings The analysis of variability (PSD) was carried in quiet state and dung respiratory movements PSD was expressed by compressed spectrum array (CSA)

, reporting consecutive spectrums analyzed every 100 beats (Figure) RESULTS PSD analysis allowed the detection of high frequency (HF) and low frequency (LF) components in fetal HRV ranging from 26 to 41 weeks of gestation These frequencies are similar to those recognized in adult patients The HF component was strictly correlated with fetal breathing movements observed by ultrasounds and corresponds to the well known respiratory arrhythmia CONCLUSIONS The original algorithm of signal processing used for the present study allows a reliable extraction of fetal ORS A CSA of consecutive series of spectrums automatically reveals the presence and absence of HF component and therefore of respiratory movements and apnea

(1

92 INTRAUTERINE FETAL GROWTH AT 5000 FEET ABOVE SEA LEVEL. L. A. Izguierdo. W. H. Barstow', C. Qualls, L. B. Curet. Dept. Ob/Gyn, Univ. of NM., Albq. NM. OBJECTIVE: To analyze intrauterine growth at an altitude of 5000 feet above sea level, in order to determine the most appropriate standard of birth weight charts to be used at this altitude. STUDY DESIGN: 3147 singleton deliveries were reviewed to determine (1) birth weight (2) residence at an altitude of 5000 feet (3) dating of pregnancy. Birth weights were compared to birth weights from California and Denver. We performed a sample T-test at each week of gestational age. A P-value of less than 0.01 was considered significant. RESULTS: 1) there was a significant difference in birth weight between Albuquerque and Denver. 2) there was no difference between birth weights in Albuquerque and Californ

. 3) Hispanic babies were significantly smaller than Anglo-American babies. CONCLUSION: Neonates born at 5000 feet above sea level fit the growth curves developed for babies born at sea level in California in 1981 and not those obtained in babies born at altitudes in Denver in 1961. These observations may be due to the differences in nutritional intake by the pregnant women over the 2 time periods of observation.

94 PEAK VELOCITY OF THE OUTFLOW TRACT OF THE AORTA AND HEART RATE CHARACTERISTICS IN GROWTH RETARDED FETUSES E Farrar'. M Bellot4, A Barbers, L Flirt, P Boaeltl and G Pardi Dept Ob/Gyn, ISBM San Paolo, Umv Milan, Italy OBJECTIVE The purpose of this study was to verify if and to what extent, peak velocity of the outflow tract of the sorts is correlated with fetal heart rate in growth retarded fetuses DESIGN OF THE STUDY 30 growth retarded fetuses (IUGR), with abnormal umbilical pulsabkty index, were included in the study The peak velocity of the outflow tract of the aorta was measured just before standard fetal heart rate monitoring Pulsed doppkr velocimetry (sample volume =3mm, automatic angle correction) guided by color flow

mapping was used (angler-3, W) Values observed in IUGR fetuses were classified as normal or abnormal according to the lower confidence lends of our reference values Heart rate, variability, number amplitude and duration of accelerations, number and type of decelerations were visually measured by two independent observers on the best 30 minutes of recording RESULTS 17 fetuses showed an abnormal aortic peak velocity (Group 1) and 13 had a normal aortic peak velocity (arouo 2) The week of gestation of the time of examination in the two groups was 30(3) and 32(3) (p=n s) The weight at birth was 1071(456) and 1343(407) respectively (p=ns) The number of deceleration (5117) was higher in group I than in group 2 (1/13) Four fetuses in group 1 did not show any acceleration The vanabtiry, the number of accelerations, the maximun duration and maximum acceleration of heart rate are reported in table 1A higy significant regressor (prO0001, r=O 72) was observed in this series of 301UGR fetuses between the peak velocity in the nrnmmW enure and the maximum duration of acnelararnne

HEART RATE ACCELERATIONS PEAK VEL bpm variability number duration

seconds bpm

abnormal 145+9. 9 +4 4+2 21 +9 13+5

normal 139+10 12+4 6 +3 40+14 21 + < 01 0 06 0 03 0 0002 0 009

is correlated with the number and characteristics of the accelerations of the fetal heart rate in growth retarded fetuses

Volume 170, Number 1, Part 2 Am f Obstet Gynerol

95 ENDOCRINOLOGY OF TWIN PREGNANCY: INCREASES IN MATERNAL SERUM ANDROGEN. V. Daniel Castracane, ý" Kirk Ramin, b" Gabriella

Pridjian, ' Pam Chandler, " Susan Ram(n, b Brad Riffe, ' Depts. Ob/Gyn, Texas Tech Univ. HSC, Amarillo, TX, s Univ. TX Southwestern

Med. Ctr., Dallas, T%, ° & Univ. Michigan Sch. Med., Am Arbor,

MI.,

OBJECTIVE: Maternal serum androgens androstenedione (A) and testosterone (T) are elevated throughout pregnancy. In early pregnancy, this rise in T&A is thought to be of ovarian origin. The sources of maternal serum androgen levels in later pregnancy have not been delineated. Using twin pregnancies we hope to account for the continued rise in T&A in later pregnancy. STUDY DESIGN: Steroid levels in random maternal blood samples obtained from twin pregnancies in both second (n-36) and third (n=34) trimesters were measured. Normal singleton pregnancy samples were controls. T&A were examined as classic androgen parameters, estriot (EP as a marker of fetal adrenal steroidogenic activity, and estradiol (E2) as an indicator of both

maternal and fetal sources. Maternal serum levels of progesterone (P) and human chorionic gonadotropin (hCG) were studied as indicators of placental endocrinology. RESULTS: Levels of T&A are similar in the second trimester but

a marked increase in twins is seen in the third trimester when

compared with singletons (T 1.33 ng/ml vs 0.83 ng/mL and A 3.95

ng/ml vs 3.28 ng/ml). Second and third trimester levels of P and hCG in twins are elevated as expected. Mean serum levels of E.

in the second trimester are slightly greater in twin pregnancies; however, a more dramatic increase is seen in the third trimester (213 ng/ml vs 150 ng/ml) consistent with two fetal placental

units. A similar pattern is also seen for serum E2.

CONCLUSIONS: These results indicate that those hormones of

placental origin are increased in twin gestation at both second

and third trimester as expected. The increase in fetal adrenal

activity in the third trimester corresponds to the increase in E3.

The second trimester increases in T&A suggests an involvement

of the fetal adrenal and placenta in the increase of maternal

androgens in late pregnancy.

96 TiMIN FRAGMENT 1.2 AND D-D11ER LEVELS IN PREGNANCY. ýQ

Mctal(a, M. Nage, C. Greenberg', M. Hennessy, H. Kay. Dept.

Ob/Gyn and Medicine, Duke University, Durham, NC. OBJECTIVE: Fragment 1.2 is a marker for thrombosis and d-dimer is

a marker for fibrinolysis. Both are important markers for

coagulation. This study was undertaken to understand the

relationship of F1.2 and d-dimer to adverse pregnancy outcome (i. e., preeclampsia and pregnancy loss). STUDY DESIGN: Blood was collected from pregnant patients having

routine bloods drawn without evidence of disease. F1.2 was assayed

using a monoclonal antibody-based ELISA by Organ Teknika Corp.

D-dieser was assayed using an ELISA from American Diagnostics.

Final pregnancy outcomes were determined from chart review. Data

and statistical analysis were performed using SAS version 6.04.

RESULTS: 340 samples from 249 patients (5.4-40.7 weeks) were

evaluated. MEAN LEVELS

Trimester Fragment I.? rVl Q_disar m9/

Ist 1.63 + 2.82 506.2 ± 318.4 > NS > NS

2nd 2.11 + 1.83 581.7 t 302.7

> P0.01 > P<0.001 3rd 4.48 ± 11.22 1070.5 ± 750.1

There was a significant decrease in F1.2 (0.68 ± 0.25 rM, P10.005). but not d-dimer levels in 1st trimester tosses compared to normal, but there were no differences in either marker in

association with subsequent preeclaiipsia at any trimester. CONCLUSIONS: Both d-dimer and F1.2 increase significantly from the first trimester into the third trimester of pregnancy. These data

suggest that F1.2 may be a more sensitive marker for early

Pregnancy loss than d-dinier, but neither appear to be sensitive

early markers for preectampsie. Further studies are indicated.

SPO Abstracts 305

97 THE EFFECT OF SMOKING DURING PREGNANCY ON UMBILICAL CORD BLOOD GASES. Th2W JA, Meyer BA, Wickstrom EA, Univ of MO (0 KC-St Luke's Hospital, Kansas City, MO. OBJECTIVE: To determine the effect of maternal smoking during pregnancy on umbilical cord blood gases at the time of delivery. STUDY DESIGN: A retrospective study was performed between 1-1.87 and 6- 30-92. During this time period, there were a total of 16,470 deliveries At least one cord blood gas parameter (venous pH) was obtained in 15,184 fetuses delivering during this same period. Umbilical cord blood was drawn immediately after delivery with pre-packaged, pre-heparimzed syringes, placed on ice and analyzed within 30 minutes of delivery. Data are reported as mean * SD. RESULTS: There is a statistically higher umbilical cord arterial pH in women who smoked during pregnancy when compared with non-smokers (p =0 0003). "p<005

DH P02 Dia HC0 ' BE ARTERY Non-smokers 7.28 1.08 167 1: 69 54.0 t 11.6 23.9 12.8 4.2 14.0

n: 12,113 n=1,444 n=1,414 n=1,449 n=1,436

Smokers 7.29 t . 08' 16.2 t78 53.7 t 12.3 24.0 t 31 -4.0 14.0 n=1,538 na202 n=203 n=202 n=197

VEIN Non-smokers 7.36 t 07 27.8 ± 10 0 41 8t9.6 22.0 12 8 -3.6 13.6

n=13,465 n. 1,784 n4,785 n=1,790 n=1,771

Smokers 7.361.07 27.21106 42019.4 22.3 12.8 -3.213.6 W. 719 n=245 n-246 n=245 n-245

... _. _ -. _. _ . _..,.. _.,,.. ». ».,, », ..,,,,.,. a _, cv ", eu. vnc.. rc: aus nun-smoters (16(/1,538 vs 1,567/12,113, p< .

05)

CONCLUSIONS: Compared to non-smokers, smokers have higher cord arterial blood pli and fewer cord arterial pH values 57 20. These differences are statistically, but not clinically significant

98 OXYGEN ADMINISTRATION IN THE SECOND STAGE OF LABOR AND CORD BLOOD CO-OXIMETRY. Thorp JA, Troboughx T, Evanax R, Hedrickx J, Yeast 1D Univ of MO @ KC-St Luke's Hospital; Kansas City, MO. OBJECTIVE: To determine if maternal oxygen adminstration during the 2nd stage of labor affects cord blood co-oximetry STUDY DESIGN: Patients were prospectively randomized into the study at the onset of 2nd stage All patients had a normal term gestation and a normal FHR tracing during the Ist stage of labor. RESULTS: There were 67 patients randomized into the study, 13 were excluded because of an abnormal 2nd stage FHR tracing or requirement for CS Data are reported as mean ± SD. Patients randomized to the oxygen group received 10 Umin by mask for a mean duration of 38 ± 32 minutes Compliance was documented.

Hemoglobin Hb CO Sat Hb 02 Sat Met Hb 02 Content (ml/dL)

ARTERY Control 15.2 ±1.5 0.7 , 0.6 33 51 14.8 0.710.1 7.0 , 30

n=21 n=20 n=21 n=21 n=21

Oxygen 15 7s1.7 1.3 1 16 33.8 112.6 0.7: 0 2 7.5 it 3.0 n=22 n21 n22 n=22 n=22

VEIN Control 15.3 ± 1.5 1.6 : 1.0 65.2 s 12.0 0.71 0.1 13.8 225

n=22 n22 n22 n=22 n=22

Oxygen 15 7: 1.7 2.2 : 2.0 67.7 , 15.9 08 10.2 14.7 , 3.5 n=21 n=20 n. 21 n=21 n=21

--.. _.. _...... .... ýy. o., ýý . ýýnýy nro Lilo stage normal labor does not affect umbilical cord blood co-oximetry.

306 SPO Abstracts

99 COCAINE (COC) EFFECTS ON OVINE FETAL SWALLOWING. M. G. Ross, 'L. K. Kullama, 'M. J. M. Noland, K. Chan. Dept. Ob/Gyn, Harbor-UCLA Med Cur, Torrance, CA. OBJECTIVE: Fetal swallowing occurs primarily during low voltage (LV) ECoG activity, and fetal LV ECoG is reduced by COC. As COC and COC metabolites are excreted into amniotic fluid (AF) and re- absorbed into fetal plasma via swallowing, we examined whether cocaine alters fetal swallowing activity, and thus the resorption of AF COC. STUDY DESIGN: Six ovine fetuses (130±1 d) were chronically prepared with esophageal electrodes and an esophageal flow probe. Following a1 hour control period, fetuses received an intravenous injection of 1.0 mg/kg COC over 30 sec. Maternal and fetal blood

samples were withdrawn at timed intervals and fetal swallowing monitored for 360 min after COC. RESULTS: Basal fetal swallowing activity during the control period was 0.6±0.1 swallows/min, with esophageal flow of 0.4±0.2 mI/min. At 10 min following COC, fetal swallowing increased to 1.4±0.4

swallows/min though esophageal flow did not change (0.3±0.2 ml/min). Swallowing then returned to basal levels. CONCLUSIONS: These results demonstrate short term (10 min) stimulation of fetal swallowing activity. Despite suppression of LV ECoG, COC does not suppress fetal swallowing and thus may facilitate recirculation of AF COC.

100 ESTIMATION OF FLOW AND PEAK VELOCITY (PV) IN THE MAIN PULMONARY ARTERY (WA) AND RIGHT PULMONARY ARTERY (RPA) IN THE FETUS FROM 17 TO 40 WEEKS GESTATION BY DOPPLERECHOCARDIOGRAPHY. 1 R, Stanlev, '1. C. Vedle, L. Steele. ' Dept. of Ob/Gyn, Bowman Gray School of Medicine. Winston-Salem, NC. OBJECTIVE- To describe flow characteristics of the MPA and RPA in normal fetuses. Changes in MPA and RPA flow charactenstics may reflect fetal pulmonary abnormalities such as pulmonary hypoplasia. STUDY DESIGN: Fifteen normal fetuses were longitudinally studied 47 times between 17 and 40 weeks gestational age (GA) using pulsed Doppler echocardiography. Waveforms were obtained from the MPA and RPA. Three to six cycles were digitalized and averaged to determine PV and time velocity integral. Diameters of the MPA and RPA were measured using 2-D ultrasound Flow volumes were calculated from these values and the heart rate. Data were analyzed using linear regression. GA was the independent variable. RESULTS:

n r p RPA PV (cm/sec) 47 0.41 <0 01

RPA DIAMETER (cm) 46 0.87 <0.01

RPA FLOW (ml/min) 46 0.72 <0 01

MPA PV cm/sec 44 0.70 <0.01

MPA DIAMETER (cm) 43 0 91 <0.01

MPA FLOW (ml/min) 43 0 83 <0 Ol

The flow in the MPA ranged from 331 cc/min at 18-20 weeks GA to 1211 cc/min at 39-40 weeks GA. while that in the RPA ranged from 8.7 cc/min to 61.8 cc/mm. The ratio of MPA to RPA flow did not change during gestation. CONCLUSIONS: The flow, PV, and vessel diameter in the MPA and RPA

all increase with gestational age. These data in the normal fetus provide baseline information which may be useful in identifying fetuses with pulmonary hypoplasia.


101 INVESTIGATION OF AUTONOMIC CONTROL OF MATERNAL HEART RATE IN NORMOTENSIVE AND HYPERTENSIVE PREGNANCIES USING POWER SPECTRAL ANALYSIS (PSA). S.. QpýrLhVjr S. LaBerge '; N. Simpson'! Dept. Ob/Gyn, Univ. of Ottawa, Ottawa, ONT. OBJECTIVE. To evaluate the role of PSA of maternal heart rate variability as a measure of autonomic function in normotensive (NT) and hypertensive (HT) (diastolic blood pressure >9) mmHg) pregnancies. STUDY DESIGN: The ECG of 21 NT and 18 HT (9 of whom were proteinuni) pregnant women with gestational age > 26 weeks was recorded during quiet respiration while lying and stana r, y. PSA wau performed by applying a Fast Fourier Transform to 256 consecutive heart beat (R-R) intervals. Three spectral peaks were quantified and the results expressed as a proportion of total spectral power under each peak The 3rour deans were compared by paired t-test. RESULTS The total power was similar in both groups However, or standing, compared to NT pregnancies, HT pregnancies demonstrated relatively reouced power (37±5% vs 6115%,

p<0.003) in the low frequency (LF) range (0-C. 04 Hz) of heart rate variability, and increased power (37±4% vs 1621%, p<0.0006) it the high frequency (HF) range (0.12-0.5 Hz). The fall in LF power was more marked in the HT group with proteirur; a than without. There were no differences between 11T and HT while supine. CONCLUSIONS: PSA demonstrates alterations it heart ratc variability in HT pregnancy compared to IIT, reflecting c iacges in sympatho-vagal balance. This objective and sens-, ve technique reflects the severity of pre-orlaeps, a . nd ray oa of value in its early detection.

102 UTERINE ARTERY RESISTANCE TO BLOOD FLOW DURING PUERPERIUM: A LONGITUDINAL STUDY. A. J. Jaffa z 1. Wolman. J. Salti, J. Har-Toov, I. Gull, M. R. Peyser, Dept. of Ob/Gyn "A", Serlin Maternity Hospital, and Sackler School of Medicine, Tel Aviv University, Israel. OBJECTIVE: The study was undertaken to assess the changes in the resistance of uterine arteries during puerperium. STUDY DESIGN: In a longitudinal study, the uterine arteries of 60 patients with uncomplicated pregnancy and delivery were examined transvaginally (n - 755) with computerized continuous-wave Doppler. Measurements were taken for the first 3 days after delivery, and once a week for the following 9 weeks. The control group consisted of two subgroups: 1) 220 normal pregnant women at term, and 2) 40 nongravid patients. RESULTS: The mean pulsatility index (P1) of the first 3 puerperal days (1.2 t 0.27) was significantly higher than that of the 3rd trimester of normal pregnancy (0.77 t 0.14). The PI decreased significantly to 1.06 t 0.19 in the'second postpartum week, and remained relatively low until week 4 postpartum (1.12 ± 0.19). Thereafter an increase in PI to 2.0 ± 0.53 was observed between the 5th and 9th postpartum week. This PI was still significantly lower than that of the nongravid controls (2.62 ± OS9). CONCLUSIONS: Uterine vascular resistance Increases soon after delivery. Vascular resistance decreases between the 2nd and 4th weeks postpartum and thereafter increases up to the 9th week, without return to the nonpregnant values.

Volume 170, Number I, Pail 2 Am] Obstet G}'necol

103 A TWENTY-FOUR HOUR CORTISOL RHYTHM IS PRESENT IN THE HUMAN NEWBORN. GJ Valenzuela, AM Germain, DL Hess, CA Ducsay, M Seron-Ferre. Div. Perin Biol., Loma Linda U, Dept Obstet and Gyn, San Bernardino County Medical Center, Oregon Primate Center, U Oregon, and Facultad de Ciencias Biologicas and Medicina, Pontificia Universidad Catolica, San Bernardino, California, Oregon and Santiago, Chile. OBJECTIVE. The human fetus exhibits 24-h rhythms in

physiological function such as breathing, body movement, heart rate and adrenal function. It is unknown whether these rhythms are passive (determined by the mother) or endogenously generated by

the fetus. In the latter case, rhythms should persist after birth. To test whether the fetal adrenal rhythm is endogenous, we explored if

the human newborn has 24-h cortisol rhythm. METHODS OF STUDY. Saliva was collected within 48 h of birth, at 4-h intervals during a 24-h period. We collected samples from 7 term newborn from mothers without any medical complication. Cortisol was measured by RIA. Data was analyzed by ANOVA with Bonferroni correction. RESULTS. All fetuses exhibit a 24-h cortisol rhythm. A peak of cbrtisol occurred randomly around the clock. No rhythm was seen in the mean data. When the individual rhythms were synchronized there was a significant rhythm (p <0.001). The peak value was 91.9

± 23.8; ng/m1 (SEM) while the nadir was 7.5 ± 2.5. CONCLUSIONS. This result is consistent with the presence of an

endogenous fetal rhythm of cortisol. Supported by the San Bernardino County Medical Foundation.

104 EFFECT OF PREGNANCY ON SEIZURE THRESHOLD IN

TILE HIPPOCAMPUS OF RATS. C. A. Standley`, S. M.

IrtenkauP, D. B. Cotton, Dept of Ob/Gyn, Hutzel Hospital/Wayne

State University, Detroit, MI. OBJECTIVE: Relatively few investigations have examined the

effect of pregnancy on seizure susceptibility. The present study was designed to study changes in hippocampal afterdischarge (AD)

thresholds to further understand epdeptogenesis during pregnancy. STUDY DESIGN: 16 female rats were surgically anesthetized and

a bipolar electrode stereotaxically implanted into the dorsal

hippocampus. Following one week recovery, baseline values for AD

(seizure) threshold were obtained on all rats. AD thresholds were

then re-determined on days 7,14 and 21 from baseline. Rats were then mated, and AD thresholds were re-determined at days 7,14 and 21 of pregnancy. Vaginal smears were taken 3 times weekly to

determine stage of estrus on days stimulated during non-pregnancy. RESULTS: The amount of electrical current required to initiate a hippocampal AD (seizure) significantly decreased across each of the

three stimulations before pregnancy (p<"O1)" Vaginal smears

indicated that the estrus cycle did not correlate with the change in

seizure threshold. Pregnancy did not affect seizure threshold. However, the mortality of the pups was 37.5% and tended to

correlate with longer seizure duration on pregnancy day 7 and 14.

CONCLUSIONS: Pregnancy had no effect on hippocampal seizure thresholds in this model. Repetitive seizure activity during

pregnancy, however, even without behavioral manifestations leads

to a high pennatal wastage in pups. Gross and histologic

examination of the pup brains revealed micro and

macrohemorrhages. The mechanism of these hemorrhages requires further investigation.

SPO Abstracts 307

105 THE EFFECT OF MULTIFETAL PREGNANCY REDUCTION ON LUTEAL FUNCTION. Leh, R. L. Berkowitz, G. Weiss', L. T. Goldsmith', R. Lapinski', R. Wein'. Mount Sinai Medical Center, NY, NY, and New Jersey Medical School, Newark, NJ. OBJECTIVE: Circulating relaxin, a marker of luteal function in pregnancy, has been implicated as a risk factor for prematurity. Our objective is to determine the effect of multifetal pregnancy reduction (MPR) on luteal function and relaxin secretion. STUDY DESIGN: 48 women with multifetal pregnancy after ovulation induction (26 = 3,22 = ? 4) who underwent MPR to twins were our subjects. Maternal blood was obtained on the day of MPR (10-12 wks. mean 11.6 wks) and at 14,16,20,24,30 and 36 wks. Serum relaxin was measured by ELISA. RESULTS: For comparison, relaxin concentrator in the first trimester for normal unstimulated singleton preena ties is 1.8±0.69 n /ml

IVF/GIFT P/M C n= 19 25 4 Pre MPR relaxin (ng/ml) 18.2±9 12.1±8 5.3±3 p <. 05 Post MPR relaxen (ng/ml) 14.8±9 9.5±7 5.5±4 Last rcla=in pre diver, ! ng/mll 10.1±9 66+7 3-0±2 P= Pergonal. M= Metrodin, C= Clomid Pre & post MPR relaxin levels were significantly different only in the P/M group. The difference between last and pre MPR relaxin was significant in all groups. The number of fetuses reduced did not affect the relaxin levels or changes (data not shown). The mean gestational age at delivery was 35.5±3 weeks. CONCLUSIONS: (1) Relaxin levels are highly elevated in ovulation stimulated multifetal pregnancies. (2) Relaxin concentration is higher in IVF/GIFT > P/M >C groups, probably indicative of the initial number of follicles ovulated i. e. lineal mass. (3) Relaxin levels decrease over time during multifetal pregnancies. (4) MPR does not consistently affect relaxin concentration. (5) The number of fetuses reduced has no affect on relaxen levels. This suggests that while early pregnancy luteal rescue relies on trophoblastic hormone stimulation, luteal function in midpregnancy is quantitatively independent of trophoblastic function.

106 COCAINE'S EFFECT ON OXYTOCIN IN THE BABOON DURING LATE PREGNANCY. MA Morgan. MBOM Honnebierx, T Myersx, J Winterx" C Mecenasx, PW Nathanielszx". TJ Garite, Dept. Ob/Gyn, Univ. of Calif. Irvine, Orange, CA and Laboratory for Pregnancy and Newborn Research, Cornell Univ., Ithaca, NY. HD 21350 Objective: The mechanism of how cocaine stimulates uterine contractility, resulting in preterm labor, remains unknown. We aimed to determine intravenous cocaine's effect on plasma oxytocin levels in the gravid baboon. Study Design: Five gravid baboons at 86 - 150 days gestation (term 180 days) had maternal femoral arterial and venous catheters surgically placed under halothane anesthesia. Five days after surgery, cocaine hydrochloride 0.5,0.75 and 1.0 mg/kg by maternal weight were infused I. V. 24 hours apart into awake baboons. Arterial blood samples were obtained at -30, -15, -5. +5, +15, and +30 minutes before and after cocaine. Plasma oxytocin levels were determined by a specific RIA. The mean baseline samples were compared to the post-cocaine samples and reported as percent change from baseline. Data are reported as mean ± SEM. Results: Oxytocin levels significantly increase after 1.0 mg/kg I. V. cocaine (Figure). Conclusion: Cocaine T stimulates oxytocinm T. JI secretion in a dose- 1° dependent manner and may be an etiology for preterm labor in those using cocaine during pregnancy. esi

M+uMC. ner ooc. uýe

308 SPO Abstracts

107 TUMOR NECROSIS FACTOR-aa. IN PREGNANCIES ASSOCIATED WITH PREECLAMPSIA OR SMALL-FOR-GESTATIONAL-AGE NEWBORNS. F�Schiff. S. A. Friedman, ' P. Baumann' R. Romero, and B. M. Sibai. Departments of Obstetrics and Gynecology, University of Tennessee, Memphis, and Wayne State University. Detroit. OBJECTIVE. To determine the presence and concentration of tumor necrosis factor-a (TNF. a) in maternal and feral plasma in pregnancies associated with preeclampsia (PE) or small-for-gestational-age (SGA) newborns. STUDY DESIGN: Maternal and feral plasma TNF41 concentrations were measured in nonpregnant women (n " 12), women with normal pregnancies (n " 24), and women with pregnancies associated with severe preeclampsia In " 23). SGA newborns (n= 14), or both preeclampsia and SGA (n. 12). TNF-a was measured with "C"s,. tive and specific enzymatmmunoassay. RESULTS: TNF-a was detected in 89% of the samples studied. Levels ranged from .r1.5 to 30 pg/ml. Median levels (pg/ml) are presented below. Maternal and fetal TNF-a concentrations in the group with idiopathic SGA were significantly lower than those of control groups. Similar levels were found in women with severe pit edampais wich or without SGA, women who delivered vaginally or abdominally in the control groups, and nonpregnant women. The route of delivery did not affect TNF-a levels in both the maternal and fetal plasma. Concentrations of TNF-a in fetal arterial plama were significantly correlated with those in fetal venous plasma (r-0.51, p. 0.01), but weakly correlated with those in maternal plasma (r- 0.34, p- 0.11).

PE PE. SGA SGA CSVD CCS CNP M+rernal 64* 74* 2.7 t 70 9.3 8.1 Fetal artery 3.4 8.1 " 1.9 t 5.9 11.4 Feral vein 5.3 4.2 " 2.1 t 7.5 11.7 CSVD. control with spontaneous vaginal delivery; CCS, control with cesarean section; CNP, control nonpregnant. " p>. 05 compared to CSVD. CCS, and CNP t p! 5.01 compared to CSVD, CCS, and CNP

CONCLUSIONS: Our study demonstrates a significant decrease in maternal and feral plasma concentrations of TNF-a in pregnancies associated with idiopathic SGA newborns. This reduction may have endocrinologic importance or maybe reflective of widespread paracrine and autocrine events. On the other hand, our findings do not support a fundamental endocrine role of TNF-a in preeclampsia.

108 FL WE= GUN AT ter,: MOM NPuFI« L OHElY. G Wt 4HSais ai J Hiff? 1. Dept. Qwt+ru Misse Fu ti Hospital, Lc Thjelse, (a. aalQVE: 1b detern¢ne the effect of rtatanal cbasity txi rate of fetal weight in at 37.0-42.0 weeks in rm, d abeticC3xaaianswithux limted Fxegkincies. S1LJ t Bi : 1151 gravidas wing tniver'sal gltxzlse acreer&ig (car) were enlisted. Non-O sia s, patients not cgti iauy dated & patients not delivering at 37.0-42.0 uedcs were excluded. Patients with factors having indspaidant effects upon rate of fetal weight, in were au hired: GST l_135 with any elevated value a1 3 LT; nil i11 ; &stetrical amplicatims; sinking cr s stage alxse. 321 pregnancies retained fcc analysis. PMregr nt body n irdoc (Da) was used to quantify awry: n3mal all '25 Afi; ' dome > 3D ky. N The shape of the fLntirn relating bird i rt (aa) to gyrational age (G4) uas dsrivel. Ptiltiple regression was used to test the effect of EMI rn BVG a=mlling for Gk. REST : Ta1 is a linear funticn of GA at tar EM & fetal gander affect the rate of fetal weight spin (1 ) (both at p(0.01) acocxdirig to the egmtir : Is (gw�d) _ 10.84 + (0.54 x s) + (0.07 x aII) (laJm) rtiae s=1 for Hales and s. 0 fcc feieles. Ile rten FCC was 12.71t1.43 (3ED) giVd (95% C[ 9.89-15.54). The rate was only 0.54 gild greater &r obese than for ranal %eight gravk as. GST results were riot predictive of ai ixdeper ant. of au . O; rüz X. 0iitraty to ptblished cpinirn the effect of maternal coesity ip n rate of fetal . eight gain at term is minirral and dJni lly j icait,

January 1994 Am

.1 Obstet Gvnecol

1 09 FETAL CARDIAC EFFECTS OF TOCOLYSIS. J. Blackstone . D. Friedman,

IA Hoskins, BK Young, Dept of OB/GYN, NYU Medical Center, NY. NY OBJECTIVE: To Identify and characterize any changes in fetal cardiac function occurring while mothers received tocolytic therapy, utilizing the combined ventricular shortening fraction, (CVSF), an echocardiographic Index of fetal systolic cardiac function. STUDY DESIGN: A previous study suggested that chronic oral ntodrine tocolysis was associated with reduced fetal systolic cardiac function. Therefore, 30 patients diagnosed with pre-term labor and eligible for tocolytic therapy were the subjects of this prospective non-randomized cohort study. 18 patients were treated with subcutaneous, (SO), terbutaline, 5 with intravenous, (IV), rltodrine, and 9 with IV magnesium sulfate, (MgSO. ). All

were later maintained on oral therapy with either terbutaline or ntodrine. Each fetus was studied on 4 separate occasions: before treatment, while on a therapeutic IV or SO regimen, during oral therapy, and after birth. Each evaluation consisted of a biophysical profile, umbilical artery Doppler wave form study, and an M-mode tracing of ventricular wall motion generated from

a 4-chamber view of the heart to assess and diastolic, (ED). and end systolic, (ES), dimensions. The CVSF was then calculated as ED-ES/ED x 100%. Multiple analysis of variance was used to compare means over time for each variable. Means between groups were compared using the two- tailed student t-test. RESULTS: No significant change was noted In the mean CVSF of fetuses who had been exposed to tocolytic agents, all of whom had normal studies. The mean CVSF pre-treatment was 34.8% as compared to 33.9% in patients treated with beta-mimetics. Those treated with MgSO, had an improved mean CVSF of 37.9%. Doppler and biophysical profiles were normal, and preterm labor was successfully stopped in all cases. All postnatal studies were normal and pregnancy outcomes were good. CONCLUSION. Short term treatment with commonly utilized tocolytic agents does not appear to affect fetal ventricular function In this study.

1 10 SLEEP PATTERNS IN PREGNANCY: A LONGITUDINAL STUDY OF POLYSOMNOLOGY RECORDINGS IN PREGNANCY. S J. Schort, A. Chawla', S. P. Chauhan, C. A. Sullivan', R. W. Naef, BI, J. C. Morrison. Depts. Ob/Gyn and Psychiatry, Univ. of Mississippi Medical Center, Jackson, MS. OBJECTIVE: During pregnancy two of the most common complaints are easy fatiguability and excessive tiredness. Since the only known physiologic relief for these symptoms is increasing sleep or rest time, sleep patterns in pregnancy could be very different than in nonpregnancy. This study was designed to evaluate the differences of sleep in early and late pregnancy as compared to nonpregnant controls. STUDY DESIGN: Four pregnant women were studied longitudinally during their pregnancy. Polysomnology recordings were performed in the first trimester and again late in the second trimester. Recordings were performed as inpatients in the somnology laboratory. Measurements included

clcctroencephalogram, electrocardiogram, electromyogram, testingofabdominal breathing movements, and continuous pulse oximetry. Four healthy nonpregnant women matched for age and weight were used as controls. Each patient was evaluated for the time that she spent in sleep latency, stage 11 latency. REM latency, and total sleep time. The total sleep time was recorded and percentages of each sleep stage generated. RESULTS: Qualitative differences in sleep between pregnancy and control patients were evident. Control patients displayed a normal appearance of slow wave sleep in stage III and IV (delta sleep). When pregnant patients did display delta sleep, it appeared abnormal secondary to extensive alpha wave intrusion. Even when including this abnormal delta sleep in a quantitative comparison. pregnant patients had a significantly shorter percentage of total sleep time spent in delta sleep (5.8 ± 8.1 versus 21.9 + 12.1. p-0.02). There was so significant difference in any of the other stages of sleep. CONCLUSIONS: Sleep in pregnancy is characterized by a loss of normal slow wave sleep. Thus, sleep stages III and IV are shorterned during pregnancy. This sleep alteration is persistent when followed longitudinally in pregnancy

Volume 170, Number 1, Part 2 Am J Obstes Gynecol

111 INCREASED STROKE VOLUME IN FETUSES WITH HEART BLOCK. M AJexander~, KD Wenstrom, W Johnson'. University of Alabama at Birmingham, Birmingham, AL OBJECTIVE. To document that the fetal heart has the capacity to increase stroke volume in the face of complete heart block. STUDY DESIGN: Measurements of left and right ventricular fractional shortening (an index of ventncular function which correlates with stroke volume) were obtained from two fetuses with complete heart block and no structural defects. Measurements were obtained antepartum and postpartum using M-mode sonography, and compared to published measurements from normal fetuses (DeVoe et at., Am J Obstet Gynecol 1984; 150: 981- 8). No medications other than steroids for control of maternal lupus were given. RESULTS:

Fractional Shortening Gest. Age LV ormall RV (Normal) Stroke Volume

#1 272 80% (33.1) 599,6 (32.1) ---- 33' 36% (33.1) 62% (32.1) ---- 35° 36% (33.1) 63% (32.1)

I month 42% ---- 11.4 cc/stroke

#2 32' 50% (33.1) 50% (32.1) ---- 5 days 29% ---- 12.6 cc/stroke

*Fractional shortening = (end diastolic - end systolic) + end diastolic LV = Left ventricle; RV = Right ventricle

CONCLUSIONS: These two fetuses were able to increase their fractional shortening (stroke volume) in response to persistent bradycardia. This supports the theory that the Frank Starting mechanism is operational in the fetal heart.

112 ACID-BASE STATUS AT BIRTH IN SMALL FOR GESTATIONAL AGE VS APPROPRIATE FOR GESTATIONAL AGE 51,000 GRAMS INFANTS. FL Gaudier. RL Goldenberg, M DuBardx. KG Nelsonx, JC Hauth. University of Alabama Hospitals, Birmingham. Alabama OBJECTIVE: To examine the difference in umbilical artery acid-base status between small for gestational age (SGA) and appropriate for gestational age (AGA) extremely preteen infants. STUDY DESIGN: 664 livebom infants :51,000g, 109 of which were SGA, delivered between January 1979 and December 1991 with umbilcal cord acid-base measurements were studied. Umbilical artery blood samples were obtained at delivery from a doubly clamped segment of umbilical cord. The samples were analyzed for pH, carbon dioxide pressure (PCO2), oxygen pressure (PO2), and bicarbonate (HCO3) content. Infants were classified as SGA using the 10th percentile of Brenner et at.. RESULTS: SGA infants had lower mean umbilical artery pH (7.23 ± 0.10 vs 7.26 ± 0.1 1, p <. 001). higher PCO2 (54.96 ± 13.03 vs 48.00 t 13.81, p<. 001), andlower P02(16.13±8.24vs21.47t9.37, p<. 001) than did their AGA counterparts. Umbilical cord bicarbonate was similar between the two groups (21.16 ± 4.40 vs 20.66 ± 4.20, p= NS). The percent of SGA and AGA in various cord gas groups and the associated odds ratios and 95% Cl for an SGA infant having that cord gas value are shown in the table. The increased incidence of fetal acidemia (pH 5 720)

and lower P02 in SGA infants remained significant in regression analyses even after controlling for gestational age, birthweight. mode of delivery, and anesthesia. Umbilical Artery SGA AGA odds ratio 95%CI

pH 5 7.20 36.7% 21.4% 1.99 (1.27,3.14) PCO2 >65 18.4% 10.3% 156 (0.88.2.77) P02 514 50.5% 20.8% 3.04 (1-95.4.74) HCO3 <17 17.6% 13.5% 1.66 (0.93,2.96)

CONCLUSION: Extremely preterm infants who are SGA as birth have a higher incidence of umbilical cord acidemie and a lower P02,

SPO Abstracts 309

113 THE ONTOGENY OF HYPERCOAGULABILITY IN NORMAL PREGNANCY AND PUERPERIUM. J Lanouettex, A& Saleh, HP Dombrowski, EF Hammen'. Grace and Hutzal Hosp., Wayne State Univ., Detroit, MI. OBJECTIVE: To evaluate changes in blood coagulation in normal pregnancy. STUDY DESIGN We measured thrombin-antithrom- bin III complexes(TAT), prothrombin fragment 1+2(F1+2), D-Dimer(DD), urokinase (uPA), tissue plasminogen activator(t-PA), plasm1n- ogen activators inhibitors 1 and 2 (PAI-1 and PAI-2), and fibronectin(FN), in non-pregnant controls (N-15), pregnant women [<12 weeks (N=28), at 16-24 weeke(N=19), at 24-30

weeks(N-16), at 30-36 weeke(N=27), at 36-40 weeks(N=31)), immediately poetpartum(N=35), two days poetpartum(N=30), and at 6 weeks pp (N=5). RESULTS: All parameters increased with gestational age (p<0.0001) except for FN. Before 12 weeks, only PAI-2 levels increased

and correlated with TAT (r2=0.34, p<0.005) and with DD (r2=0.5, p<0.0001). F1+2 and TAT increased at 16 weeks followed by in DD at 24

weeks, PAI-1 at 30 weeks, and uPA at 36 weeks. t-PA increased immediately after delivery. F1+2 increased at 2 days PP.

CONCLUSIONS: 1)Enhanced thrombin generation in first noted at 16 weeks, followed by enhanced fibrinolysis at 24 weeks. 2)The trophoblast modulates maternal hemostasis by increasing PAZ-2 in the first and PAI-1 and uPA in the third trimester. 3)PP resolution starts at 2 days and is completed by 6 weeks.

114 "P-NMR SPECTROSCOPY MEASUREMENT OF

INTRACELLULAR FREE MAGNESIUM AND PH IN

ERYTHROCYTES OF NONPREGNANT, PREGNANT, AND

GESTATIONAL DIABETIC WOMEN. M. Bardicci', LM Resnick`,

O Bardicef ,Y Sorokin, DB Cotton. Depts. Ob/Gyn and Int. Med.,

Wayne State University, Detroit, MI

OBJECTIVE: To noninvasively compare intracellular free magnesium (Mgi) and pH (pHi) in normal pregnancy and gestational diabetes.

STUDY DESIGN: We utilized 31P-NMR spectroscopy to measure

intracellular Mgi and p1-li in red blood cells of fasting nonpregnant (NPN, n=18), normal pregnant (PN, n=17), and diet controlled

gestational diabetic (PD, n=12) women. RESULTS: Group 1ý3`L PLI Pit.

Mgi(MM) 162±5 159±7 139±6"

pHi 7.29±0.02 7.24±0.01 " 7.23±0.01

* sig=0.05 (ANOVA)

CONCLUSIONS: 1) Pregnancy is associated with a shift in erythrocyte

pHi towards more acidotic values, which may be helpful in tissue and

placental oxygen delivery, and 2) Mgi is lower in gestational diabetes as

compared to normal pregnancy. Since lower Mgi are also found in other insulin resistant disorders, we hypothesize that cellular magnesium depletion may contribute to the pathogenesis of gestational diabetes.

Altogether, these data emphasize the utility of NMR as a tool in studying

cellular ton metabolism.

310 SPO Abstracts

115 CELLULAR MAGNESIUM DEPLETION IN PREGNANCY M Bardicef', LM Resnick', 0 Bardicef, Y Sorokin, J Evelhoch', BA Mason', DB Cotton. Depts. Ob/Gyn and Int. Med., Wayne State University, Detroit, MI. OBJECTIVE: To determine if intracellular magnesium levels are altered in pregnancy. STUDYDESIGN: Weutilized"P-NMRspectroscopy tomeasure intracellular free magnesium levels(Mgi) and intracellular pH (pHi) in brain, skeletal muscle, and peripheral erythrocytes of nonpregnant (NP, n=8) and third trimester normal pregnant (P.

n=8) women. RESULTS: Brain Sk Muscle $$C Mgi(I&M NP 544178 637±45 161±5

P 357ß0" 479±50" 159±7 AHi NP 7.04±0.03 7.09±0.005 7.29±0.02

P 7.0610.02 7.0810.01 7.24±0.02 "P< 0.05 vs. NP

CONCLUSIONS: 1) Cellular magnesium depletion is a characteristic feature of normal pregnancy; 2) Brain and skeletal muscle Mgi, compared to RBC levels, may be more sensitive indices of magnesium status; and 3) Since low Mgi levels are also found in essential hypertension among nonpregnant populations, lower Mgi levels in pregnancy may predispose to hypertensive disorders of pregnancy, such as pre-eclampsia.

116 THE FffrAL HAPa(ODYNAMIC R82ONSB TO mynatO TRANSFUSION - AN OVINE MODUL S. MacohaiP. R. Morrow. Perinatal Research Unit; Mount Sinai Hospital, University of Toronto, ONE CANADA. OR78CITV8 To develop an ovine model which would allow quantification of the baemodynamie changes induced In the anaemic fetus by the in-utero transfusion of a large volume of densely packed red cells (RBC). STUDY DESIGN. 6 chronically catheterised fetal sheep (124 days) were made anaemic by slow haemorrhage (210mla in 2 days) (H) and then transfused (T) rapidly with maternal RBC. Mean arterial pressure (MAP), venous pressure (VP), heart rate (HR) umbilical placental flow(UPP) were measured and umbilico-placental resistance (UPVR) calculated during the H, T and until 24 hours later. RESULTS Data presented as mean and (ISEM).

MAP (mmHg)

VP (mmHg)

HR FLOW mit/min/kg

UPVR mm/ml

re H 41.3(1.8) 2.37(0.72 173.7 1.6 175(2.1) 0.

re T 40.9(l. 0) 2.67(0.36 192.8(4.4) 211.3(1.9 0.0554(. 006

post T SS. 1! 9L . 145.3 1955(6.0) 0.08(. 01)

+6hr 47.4 3.0 2 0.66 180.8(11.8) 1654(5.1 0.56(. 013)

478(4.2) 209(0.46) 171.01(3.4) 179.4(5) 0.0798(. 013)

mu recut m me ao en w no c nm in MAP or VP. Dunng transfusion MAP increased 35% and there was a three-fold increase in VP. 'Iltis was associated with a significant seduction in HR and increase in UPVR. By 24 hours them was no difference from the values obtained pre H. OONa. USION. It was possible to develop a good ovine model of fetal anaemia and to measure the response to in-utero transfusion, This resulted in profound acute haemodynamic changes in the fetus with normal values restored by 24 hours after transfusion. The mechanisms by which the fetus withstands changes of this magnitude require further evaluation in both the sheep and in the human.

(nis work was supported by an MRC(Canada) award to R. Morrow).


117 SUCTION OF CALCIUM-DEPENDENT NITRIC OXIDE SYNTHASES (NOS) BY PREGNANCY. C. Weiner. I. Lizasoain", S. BaylisX, R. Knowles", I. Charles", S. Monads". Wellcome Research Laboratory, Beckenham, Kent, England. OBJECTIVES: To determine the effect of pregnancy on NOS activity, cGMP and endothelial (e) / neuronal (n) NOS specific- mRNA. STUDY DESIGN: Heart, kidney, esophagus and skeletal m. were excised from 73 time-mated pregnant guinea pigs from 0.14-0.90 gestation (term=63 days). Ten animals at term received 250 pg tamoxifen (i. p. b. i. d. for 4 doses) prior to slaughter. NOS activity was measured by the conversion of 14C-L-erginine to 14C-Lcitrulline in the presence and absence of LNMMA and EGTA. cGMP was measured by RIA. Poly-A mRNA was isolated from skeletal m. by oligo d(1) chromatography, fractionated on formaldehyde-agarose gels, and transferred to nylon membranes. The blots were hybridized with guinea pig specific e-NOS and n-NOS rRNA probes cloned by our laboratory, washed under stringent conditions, and autoradiographed. RESULTS: Ca*2-dependent NOS activity had begun to rise in most tissues by 0.14 gestation reaching 200% of the nonpregnant level by 0.30 gestation in all tissues studied. Ca*2-independent activity was unaffected by pregnancy. NO stimulates guanylate cyclase. cGMP also doubled with advancing gestation. But in contrast to NOS, cGMP declined in most tissues by 0.60 gestation. Tamoxifen reduced Ca+2- dependent activity in the heart to the nonpregnant level. Tamoxifen had no affect on the other tissues tested. The Northern blots revealed increased e-NOS and n-NOS specific mRNA at term. CONCLUSION: Our findings support the hypothesis that an increase in NO secondary to enhanced NOS synthesis, which is at least partially estrogen dependent, plays a role in the cardiovascular adaptations of pregnancy. The observation that the cGMP response to NO is down regulated over time may explain the rise in vascular resistance at term.

1 18 A PRELIMINARY STUDY OF MATERNAL FETAL TRANSFER OF 190 IN HIGH RISK PREGNANCIES Y. Bamhard', M. Landor`, A. Nassart, M. Y. Divan. Department of OB/GYN, Albert Einstein College of Medicine, Bronx, N. Y. OBJECTIVE: To evaluate the effect of high risk conditions on the trsnsplacental passage of maternal IgG to the fetus In order to Identify pregnancies at risk for reduced neonatal IgG levels. STUDY DESIGN: Radial Immundiffusion was used to measure serum Ip0levels In maternal-newborn pairs In high-risk pregnancies. The study population included 6 premature gestations (all <34wks). 11 chronic hypertensives at term, 10 prspestational diabetics at term, 16 postdate gestations, and 8 IUGR gestations > 37 weeks. Control population consisted of 28 term low-risk gestations. Maternal blood was collected on admission to the labor floor and fetal IgG levels were determined from the cord blood. RESULTS: Cord loG/Maternal IaG Controls 1.13 t 0.22 Premature 0.79 t 0.261 Hypertensive 1.08 ± 0.13 Diabetic 1.10 t 0.23 Postdate 1.10 t 0.23 IUGR 0.88 ± 0.21 "P<0.05 vs. controls. CONCLUSIONS: These preliminary results suggest: (1) Transfer of IgG is not reduced In term high-risk pregnancies compared with controls, (2) As previously shown, transplacentel passage of IgG is relatively decreased In preterm gestations, (3) Although not statistically significant, the passive acquisition of maternal antibodies may be reduced in IUGR fetuses as 6/8 had IgG levels below that of the control group. This suggests a possible inability of the IUGR fetus to resist neonatal infection.

Volume 170, Number 1, Part 2 Am J Obstet Gynecol

1 19 M: qM IUM AND

cular smooth muscle, and e affinity sites in blood vessi the treatment of preterm 4 contractile effect of (ET-1' dominantly an veins. etal Lion (IUGR), and maintain fetal blood volume in this c ited the contra mile effect of tion identical to that in whi (Ca) and Ca channel blocke

curves to EDSOIVM , FJ were comnei

HUMAN PLACENTAL u1 JV Mambouh, '

ua (MB inhibits tome in mostee of vaa- eta b of endothelm l (ET-typ1) to high

ogical doses of Mg we used in r and preeclampsia. Ti- potent, po-fid

the placental circulation is exerted pro eta of ET-l are elevated in growth retarda- e high venous tone that supports the low Bition. We investigated whether Mg inlub- "-1 oa hý ma" plaornlal veins, m aprepersthe

marked effects of extracellular calcium (nicardipine) have been demonstrated. t human placental veins were stretched to tubers. Rings were treated with Mg-free Mg solutions. ET-1 was then added cumu- ometric tensions measured. Dose response aired t-tests for ted mean applied r the curve. Individual dose response points

RESULT'S: ET-1 produced strong, concentration dependent contrac- tions in the control gýoup Mg en- �r, wyy riched solutions did not alter the dose response curve to ET-1. Q ý114 CONCLUSIONS:

LZ^- These results 10

confirm the strong contractile vo- epaose of human placental veins to EP-I. Mg does not affect this re- +-s

1101

spouse Concern has been expressed regarding the use in RKGR 46 .6 .64 ies"-characterized by high Lwo, ýr. rsrarpe

els of ET-1-of Ca channel blocken and other agents that in- hibit the placental venous response to ET-1. Such agents could comp o. mice the maintenance by ET-1 of the elevated venous tone necessary to support the hypovolemtc fetal circulation is thesepteýºencýes. The current results suggest that the use of pharmacological doses of Mg in pregnancies complicated by IUGR does pa warrant similar concerns.

120 EFFECTS OF ADVANCING PREGNANCY ON LEFT VENTRICULAR FUNCTION (LVF) DURING BICYCLE EXERCISE. Vi1, H. K. Hellerstein, B. Cherry, A. E. Bacevice. Department of Ob/Gyn, Bowman Gray School of Medicine, Winston- Salem, NC and Department of Medicine (Cardiology), Case Western Reserve University, Cleveland, OH. OBJECTIVE: Over the last few years more women exercise during pregnancy. We previously found that vigorous bicycle exercise does not compromise LVF (Am J Cardiol 69: 15(6,1992). This study examines the mechanism by which stroke volume (SV) is maintained early (E) and late (L) in gestation. STUDY DESIGN: Six pregnant patients were studied at 15 weeks and again at 33 weeks of gestation. M-mode echocardiograms were obtained at the following 3 periods: 1) Rest (R), 2) maximum exercise (Ex), 3) 5th minute of recovery (Rec). RESULTS: x+ SEM

LV EDD FS (96 Cl (1/min/m2 R (E) 43±4.9" 36.1±6.4 2.8±0.3 R (L) 48±3.7 36.8±6.0 3.8±0.5 Ex (E) 46.8 t 6.0 59.3 t 8.8 8.8 t 1.5 Ex (L) 49.6±6.7 47.2±4.4+ 7.7t 1.0 Rec (E) 50.2 t 4.5 45.0 t 7.5 5.0 t 1.1 Rec (L) 49.5 t 3.8 39.5 t 7.5 4S t 0.5

(*p < 0.003; +p < 0.0005; EDD - end diastolic dimension; FS - fractional shortening; CI = cardiac index). CONCLUSIONS: 1) In early pregnancy the increase in SV associated with rigorous exercise is mainly due to the increase in FS (increase in contractile reserve). 2) In late gestation this increase in SV is mainly due to an increase in left ventricular size.

SPO Abstracts 311

121 OBESITY, PREGNANCY AND LEVI' VENTRICULAR (LV) FUNCTION. I. C. Veille, R. Hanson. Department of Ob/Gyn, Bowman Gray School of Medicine, Winston- Salem, NC. OBJECTIVE: Obesity is associated with increased maternal morbidity, increased LV wall thickness and LV mass. The purpose of this study was to investigate LV function in overweight normotensive nondiabetic patients during the 3rd trimester of pregnancy. STUDY DESIGN: Eight obese (0) patients (z wt. 282 ± 20 lbs) had M-mode echo of the left ventricle done at 36 ± 2 weeks. A group of 36 normal (N) pregnant patients at 36 ±I weeks were used as control group. Results are expressed as mean ± SEM. RESULTS:

LV EDD (mm)

LVPW mm

IVSD (mm) (FS%)

Mass (gm)

CI (l/min/m2)

(0 5211 11±1 12±1 41±2 285±39 3.5±0.2 (N) 50±0.7 7±0.3 8±0.3 38±1 153±9 4.4±0.3 P NS <0.00001 <0.0001 NS 0.00001 NS

EDD = end diastolic dimension; PW = posterior wall; IVSD = interventricular septum diastole; FS = fractional shortening; Cl = cardiac index. CONCLUSIONS: 1) (0) was associated with myocardial hypertrophy, increase in ventricular wall thickness, intraventricular septa] thickness, and LV mass. 2) LV EDD, LV function were not different in the (0) group when compared to the (N) group. 3) Although the (0) patients had a myocardial hypertrophy, LV function was preserved.

122 LYMPH FLOW DURING CHRONIC FETAL ANEMIA. Davis, AR Hohimerx, RA Bracer. Oregon Health Sciences

University, Portland Or. and University California San Diego, La Jolla Ca. OBJECTIVE: To evaluate the extent to which increased lymph flow can return fluid and protein to the circulation in the chronically anemic fetus. STUDY DESIGN: Thoracic duct lymph flow rate (LF) over a range of outflow pressures was measured in 5 near term fetal sheep, 4-5 days after surgery and daily thereafter for 5 days. After each days study 60-190 nil of blood was withdrawn at a rate of Iml/min. Regression analysis was used to establish the lymph flow function curve. Total lymph protein (LP), plasma protein (PP), and LF were compared by ANOVA for repeated measures. RESULTS: After 5 days of chronic anemia the hematocrit was reduced from 35.6±1.2% to 13.7±. 6% (means±se) as LF increased from . 42±. 03 to . 86±. 03 m1/rrun, p<. 01. This increase was directly related to the fall in bematocrit. PP and LP decreased from (3.7±. 1 and 2.6±. l g/dl) to (3.5±. 2 and 2.3±. 1 g/dl) as the rate of total protein returned to the circulation nearly doubled. Jugular venous pressure was not changed. CONCLUSIONS: During chronic fetal anemia LF increases and thereby increases the return of protein to the circulation. This elevated LF plays an important role in extravascular fluid volume regulation. Supported by HL45043

312 SPO Abstracts

123 RIGHT VENTRICULAR FUNCTION IN CHRONIC FETAL ANEMIA. LE Davis, GDCiraudx, AR Hohimerx, MD Rellerx, MJ Morton'. Oregon Health Sciences University, Portland, OR. OBJECTIVE: To determine if the increase in extravascular fluid in chronic fetal anemia occurs because of heart failure or despite successful cardiac adaptation. STUDY DESIGN: Right ventricular function curves were performed in near term chronically catheterized fetal sheep at the start, midpoint and after 7-8 days of anemia induced by isovolemic daily hemorrhage. Least squares fit of the ascending and plateau lines of stroke volume (SV) versus right atrial pressure (RAP) were used to establish breakpoints (intersection of the ascending and plateau lines) -which were compared by ANOVA for repeated measures. Myocardial blood flow (MBF) was measured by microspheres. RESULTS: After 7-8 days of chronic anemia carotid arterial oxygen content was reduced from 6.7±. 2 to 2.1±. l ml/dl and the hct from 29±3 to 12.9±1% (mean±sem). At the breakpoint, SV (unchanged for controls) increased from

. 89±. 09 to 1.24±. 07 WAS (p<. 05). RAP remained unchanged, 3.5±. 9 and 2.9±. 7 mmHg. Right and left ventricular MBF were significantly increased, 1583±298 and 1362±249 ml/min/100g. Excess fluid was present in the abdomen and chest of most animals at autopsy. CONCLUSIONS: Tissue edema during severe anemia occurs despite normal RAP, increased SV and markedly increased MBF, markers of successful cardiac adaptation. Supported by HLA5043

124 OBSERVATION CdSLi111ING THE ºATIIOºKTSIQAGT OF NEMNIW ASPIRATION SYNDROME. K. Ranln', K. Lovsno. N. Kell', T. Carmody'. Dept. Gb/Gyn, Univ. of Texas Southwestern NW. Ctr., Deltas. TX. OBJECTIVE: Iypercarbia has been associated with fetal gasping. W sought to determine If fetal ecidemia and hypercarbia were linked to the developnt of m. caniuw aspiration syndrome. STUDY DESIGN: Umbilical artery blood gases in 7,748 singleton cephalic tern pregnancies with m. conius in the aenionie fluid were compared to 68 similar pregnancies where the Infant developed seconius aspiration syndrome. RESULTS: 7.816 pregnancies with aeconiun.

IEGOYIII( AVIRATIOY 1YIDR0IE Jtcom No (I) Yes (1) 1 value

No. of Infants 7748 (100) 68 (100)

ilical artery blood pW.

27.31 2536 (33) 7 (10) (. 0001

7.3 - 7.25 2380 (31) 14 (20) . 07

7.24 - 7.20 1556 (20) 17 (25) .3 7.19 - 7.10 1087 (14) 16 (23) . 03

7.09 - 7.0 147 (2) 7 (10) (. 0001

56.99 42 (. 5) 7 (10) (. 0001

65 PM9 or greater 822 (11) 21 (31) <. 0001

HC - 17 osq/L 185 (2) 4 (6) . 08

CONCLUSION. We propose that aeconius aspiration syndrome is significantly associated with hypercarbia and fetal acidosis. Thus, aieconius In the asnianlc fluid may be a fetal "erwfrorreental" hazard when asphyxia supervenes rather than a result of asphyxia.


125 PREVENTION OF LIPID PEROXIDATION IN BRAIN CELL MEMBRANES OF FETAL GUINEA PIGS BY PHENYTOIN DURING IN UTERO HYPOXIA. C. Larnolev. O. P. Misltrax, I. Forouzan. Dept Ob/Gyn, Dept of Physiology. Univ. of Penn., Philadelphia, PA. OBJECTIVE: To demonstrate the ability of phenytoin to protect the membranes of fetal brain cells from hypoxic injury. STUDY DESIGN: Studies were performed on 8 term fetal guinea pigs. Two of these fetuses came from an untreated mother (control); two from a mother treated with phenytoin, 30 mg/kg, (treated); two from a mother placed in a 7% oxygen chamber for 60 minutes (hypoxic); two from a treated and hypoxic mother. The fetal brains were harvested, frozen in liquid nitrogen, and stored at -70°F. Lipid extraction was performed on the samples. The lipids extracted were dissolved in apectrophotometric grade heptane, and the absorbance spectra of the samples between 200- 300 nm were measured. Conjugated dienen levels were calculated from this information in µmole/mg brain. Fluorescent products were measured by spectrophotofluorometry .

The amount of fluorescent products present in the sample was calculated from the relative fluorescent intensity at 435 nm. per gram of brain. RESULTS: The level of dienes in the hypoxic animals was 72 nmol/mg tissue higher than in the control animals. There was no significant difference between control treated and hypoxic treated groups. The mean relative fluorescent intensity of the control, hypoxic, treated, and treated hypoxic samples were 1.33,2.18.. 2.18, and 2.04 respectively. There was a significant difference between the level of fluorescent compounds found in the control and treated groups (p=. 023). No other significant differences were found. CONCLUSION: Phenytoin blocks the increase in fluorescent coumpounds from lipid peroxidation due to in utero hypoxia preserving nerve cell membrane structure, which may further reduce hypoxic brain injury in the fetus.

126 DECREASED SaO2 PRODUCES HIND LM HYPERTENSION AND REDUCED OXYGEN EXTRACTION N THE FETAL SHEEP. G. D. V. Hankins C. J. Harveyx. Dept OB/GYN, Wilford Hall USAF Medical Center, San Antonio, Texas and Dept OBrGYN. University of Texas Medical Branch, Galveston, Texas. OBJECTIVE: The objective of this study was to measure letal Sa02 and mean arterial pressure in the letal sheep undergoing progressive hypoxemia. STUDY DESIGN: We pregnard sheep were administered general anesthesia and pulmonary artery, femoral artery and femoral vein were accessed. Hysterolomy was performed to expose fetal hind limbs and letal artery and veins were cannulaled. Maternal and fetal units were rendered progressively hypoxic and eddemic via maternal hypoverdlation. Fetal pH, pCO2. p02, HCO3, BE, MAP, Sa02 and limb Sv02 were measured and recorded. RESULTS: Al nine subjects decreased arterial pH and base excess values. Hemodynamic charges were alegorized into two groups: fetuses that elevated MAP, and those that had no significant charge in MAP. Six fetuses deae aced SaO2 levels 528%, sgrulcanty decreased base excess, and increased hind lint MAP. Three subjects maintained Sa02 2 31% for the study period, significantly decreased base excess levels, but did eil increase MAP. In the increased MAP group, all subjects subsequerdly reduced hind limb Sv02 and oxygen extraction ratios. CONCLUSIONS: Progressive hypoxemia that resets in letal arterial Sa02 528% Is more ikey to produce limb hypertension than hypoxemia that does not siýgnill- candy decrease Sa02 (p41). Increases in letal hind limb MAP in response to hypoxemia, and the decreased oxygen delivery and extraction ratio is suggestive of a hemodynamic shunt. hderventions to maintain arterial Sa02 may be beneficial even in the severelyaddemic fetus to prevent preductal h ypoxem is and subogim um oxygen extraction.

Volume 170, Number 1, Part 2 Ar n] Obstet Gynecol

SPO Abstracts 313

127 CRITICAL OXYGEN EXTRACTION IN THE PREGNANT EWE UNDERGOING 129 FETAL PULSE OXIHETRY: TECHNICALPERFORMANCE ANDNITRAPARTUYVALUE& a, Q, ACUTE HYPOXEMIA. C. J. Harve , G. D. V. Hankins. Dept OB/GYN, University Anderso C. J. Haney", J. Van Hook T. N. Tabh, T. L. Shabf, Dopt. of OBGYN, IMN. of Texas of Texas Medical Branch, Galveston Texas and Dept OB/GYN, Wilford Ha! Medical &ar Gdwslo4 Texas USAF Medical Center, San Antonio, Texas OBJECTNEThobpdWsdthistudy wasto. vsludethep tomnnaof anwrudnobgyfwth OBJECTIVE: In to nonpregnant patient, the ability of to tissue to extract use of lost axveNan eN to IrOrapanum period and to record normal Sp02 values in term oxygen M Initially Independent of supply and affected by the determinants of pregnancies. oxyhenngbbin dissociation. No data exist confirming this physiologic phenom- STUDY DESIGN: From October 1990 to Jilt' 1901 tare Yuapowm patients who proved to labor ans in pregnancy. The objective of this study was to evaluate the effect of and delway in active lobo" sith ro widawa of 4ieetion, beading, or placenta prsvia were smGed pregnancy with Its resultant change In oxyhemogtobln dissociation on critical AskVis *0 reflectance pulss oxinarter (Neficar N-400 %vith N-1 0 sensor &signed for foal use) wair oxygen extraction applied to ft presenting foal head doing vaginal exrNnstion. Fatal preductalpubas wersdotaded STUDY DESIGN: Pregnant sheep (n. 6) were admkdstared general anesthesia via co npter¢ad LCD readout and the sans was a4sted aooodrp to readout Otatettrical ears and pulmonary artery, femoral artery and femoral vein canalization were per- providers wasbindedtotle Sp02rectedin{parid time were retrospectively wAinied. AAwialud formed. Maternal and fetal units were rendered progressively hypoxic and verouxundficalemdfioodgasnandeooximegwomdononalnwrouaMabnrixbjaeöwn acidernic via maternal hypoventilation. Maternal hemodynamic, oxygen transport evaluated for eonnplbaloraandneonates were sominedfortrsumsandInfection. and oxygen extraction variables (MAP, MPAP, CVP, PAWP, CI SVRI, PVRI, RESULTS: 167naöwr-gaxpairs "menrolled. Mean gestational sgarea 30.404; Mean cervical Sa02, SvO2, CaO2, CvO2, D02, VOZ 02ER) were recorded examination at the Wm of senor plrnrl wau 6 WOW% 0 -1 sta. Ex~s reported man RESULTS: Progressive, hypoxemia Increased D02, V02 and 02ER by 25,37, ease of appfration was 3 (scat t- 5; 5. very dilticulQ. Sensor padamance (extract with foal OA and 64 percent� respectively. Mean critical oxygen extactbn Increased sigrdS- identification of puttees edh '50%confdsnw) in at study subjects averaged 57.7% (range .. 5%. candy to 53% (range . 39% to 69%).

i 95.2%ß Performance br. 4an-52%: 5-7crn-50.7%; 6-t0cm-63.11%Moan 1sWSpO2 during labor

Ind vidual subjects had heterogeneous responses that could be categorized into Is bebw: three groups 1). Predominant Increase in D02 (n. 2); 2). Increase In V02 (n=2), or 3). and Increase in 02ER (n. 2). The one subjects that had no detectable -ý Increase in 02ER had a Hgb level 25% lower than the mean. ý Y CONCLUSIONS: Oxygen extraction patterns In # is pregnant awe appear to be bimodal In natrre. initially, 02 extraction is 02 supply dependent Below a critical

-- M 02 supply. extacdon becomes delivery dependent This response Is similar b : the delivery dependent 02 consumption seen In human sepals. A critical 02 extraction ratio o17O%has been hypothesized in the human nonpregnant model; maximum ER measured In this study was lower with Inter subject variability. CONCLUSIONS: Foal puhsoa nevyudrparoninvasiwtnrefectanawraorpedormi58%d Decreased oxygen utilization may be species dependent oxyhemoglobin disso- frordorirp tires. and improves as labor proses and poor contact is achieved between the clation dependent, Hgb concentration dependent, or multifactodal. Reduced photodetedors ad the NW tile. Fatal Sp02 values do rot significantly Berge In labor, twdike critical oxygen extraction in pregnancy may predispose patients to dysoxia in previously reported form for pH. Variability of foal SpO2 values dhri g labor leid xuppon to the acute hypoxemic stress. prairies that letal hrnogbtin Saturation is a dynsr* process the to the location of the tetut an the

oxytwmoglotin dissociates axw.

128 THE EFFECT OF PREGNANCY ON MATERNAL Sa02 VALUES AT BIWEEKLY INTERVALS AT SEA LEVEL J Van Hook C Harveyx, Dept Obstetrics and Gynecology, Dep. of OB/GYN, University of Texas Medical Branch, Galveston, Texas, 77555 OBJECTIVE:, DisUo pregnancy, the oxyhemogbbin dissociation curve shifts to the rgtd to enhance oxygen delivery to the fetus, resulting in a chronic maternal state of compensated respiratory ankabsis. The objective of this study was to evaluate the etfed of dissociation stall on maternal Sa02 values IMaighoU pregnancy. STUDY DESIGN: Pregnant patients presenting to the obstetrical clinics br prenatal care andtothe tabor anddelivery unit were enrolled nä the study. Gestational age was established by accuracy of historical dates 01 last menstrual period, fetal ultrasound examination prior to 24 weeks, or a combination of both. An subjects were screened for acute and chronic disease, compromise of pregnancy, and fetal complications. A Nelbor14-1Opulseoximeterwasused with a25Ldigital sensorappledtothefirst digi of the dominant hand. Mean values over one minute were recorded. RESULTS: 881 patients were enrolled nthestudy at gestational ages 8 to 42 weft 366 of the subjects had no history or evidence of maternal cardiorespiralory disease (no hypertension, preedampsia, asthma, pulmonary edema, heart disease, Infection, lever, or smoker) and had established fetal growth that met criteria for gestational age. Mean Sa02 was in the low risk group was 98.0% (STD t1.7) and there was no sigrdficant change at any gestational age. CONCLUSIONS: Maternal Sa02 is a stable component of oxygen transfer during pregnancy and does na significantly change from 8 to 42 weeks gestation. Normal fetal growth is most likely dependent upon the maintenance of SaO2 Weis and the absence of maternal or fetal anemia W N19 Sa02 appears to be stable in healthy pregnant subjects, monitoring during pathophysiologic stales may be an inportani determinant of fetal 02 availability.

130 FETAL PLACENTAL BLOOD FLOW IS AFFECTED BY MATERNAL GLYCEMIC PROFILE IN DIABETIC PREGNANCIES. Elliott BD, Langer, 0., Valdez, M. -, Dept. of Ob/Gyn, UTHSC, San Antonio, OBJECTIVE: Maternal hyperglycemia has been associated with fetal hypoxia and utero placental insufficiency in pregnant diabetics Fetal umbilical vein flow represents a distal measure of total fetal placental blood flow. We sought to investigate the effect that glucose levels have on fetal placental blood flow using this modality in diabetic pregnancies. STUDY DESIGN: 89 singleton patients (26 diabetic. 63 normal) underwent umbilical vein velocimetry and standard biometric measurements to confirm gestational age and fetal weight (Shepard) Vein diameter and peak velocity corrected for angle of insonation were used to estimate flow by- Flow (cc/min) = nrz (cm2) x Velocity (cm/sec) x 60 Maternal serum glucose levels were obtained in the diabetics from serial data collected by memory reflectance meter RESULTS. A 25% difference existed in mean fetal placental flow between groups by Student's t test, and normal distribution was assured by Kolmogorov-Smirnov test

Flow Rate EGA EFW Peak Velocity (ccimin) (wks) (gms) (cm/sec)

Diabetic 438 2 29 1,458 336 Normal ------

330 2 --------

29 -----

1,398 -----

29 2 ----------

=0.01 ns ns -

p=O Additionally, there was an inverse relationship in diabetics between fetal placental flow rates by estimated fetal weight (EFW) and mean maternal serum glucose level CONCLUSIONS: Fetal placental blood flow is increased in diabetics, and is inversely related to maternal serum glucose levels We speculate that higher baseline flow facilitates glucose transport in diabetes, further increasing fetal glucose load Likewise, decreased flow as a result of maternal hyperglycemia may be a mechanism by which utero placental insufficiency evolves in the poorly controlled diabetic

314 SPO Abstracts

131 THE EFFECT OF THIGH-LENGTH TED HOSE ON THE HEMODYNAMIC RESPONSE TO PROLONGED STANDING IN PREGNANCY. C. Hobel, D. Rosen , J. Oreenspoon, L. Castro, D. Micro, S. Newim'. Dept. OB/GYN and Div. Biosets, Cedars-Sinai Mod. Ctr. and UCLA Sch. of Med., Los Angeles, CA. OBJECTIVE: During pregnancy the standing position is associated with changes is maternal cardiovascular parameters due to a disturbance in venous return from the lower extremities. The purpose of this study was to assess the effect of TED hose on the hemodynamic response of pregnant women moving from the supine to the standing position. STUDY DESIGN; We assessed the cardiovascular status of 12 normal pregnant women in the second and third trimesters using non-invasive thoracic electrical bioimpedance (TEB) measurements of cardiac output/cardiac index (CI) and systemic vascular resistance/systemic vascular resistance index (SVRI) in the supine (30 min. ) and standing (45 min. ) positions with and without support stockings (TED Hose/I8 mmHg at ankle). A two factor repeated measures analysis of variance was used to test for differences in position and stocking use. RESULTS: Prolonged standing was associated with a significant increase in heart rate (HR) and blood pressure (all p values - <0.001). With the use of TED boss there was a trend toward blunting the increase in HR that occurred with standing. TED hose use significantly increased SVRI in the standing position (p <. 005) and was associated with a borderline decrease in Cl (p-0.054). CONCLUSIONS: This study documents that significant cardiovascular changes occur when pregnant women stand. Our data suggests that a greater increase in heart rue is needed to maintain the BP in patients without TED hose. TED boss increase the total peripheral vascular resistance, presumably by improving preload and enabling patients to maintain BP and cardiac output during standing with smaller increases in HR. Additional patients are being studied (supported by Kendall Healthcare Products).

132 FETAL PLACENTAL BLOOD FLOW IN A POPULATION AT RISK FOR GROWTH ABNORMALITIES AND PLACENTAL INSUFFICIENCY. Elliott. B D. Langer, O. Dept Ob/Gyn, Univ. of Texas Health Science Center, San Antonio, Texas OBJECTIVE: Although fetal placental blood flow is a critical issue in the evaluation of abnormal fetal growth and hypoxia, its direct measurement is not possible with present technology Umbilical vein flow by doppler velocimetry estimates total fetal placental blood flow Our purpose was to explore this modality in gestations at risk for placental flow abnormalities and correlate with standard physiologic and biometric measurements STUDY DESIGN: 120 consecutive patients who were at risk for flow abnormalities. (ie hypertension, diabetes, growth abnormalities, abnormal placentation, twins, drug abuse) were studied as they presented for obstetric sonogram. Umbilical vein peak velocity and diameter, and umbilical artery S/D ratio were obtained, in addition to standard biometric measurements (Shepard). Umbilical vein flow was calculated by: Flow (cc/min) =xr2(cm2) x Velocity(cm/sec) x 60. RESULTS: A significant association existed between Gestational Age and Umbilical Vein Flow (UBF) (r=0 83, p<0 0001), and between Estimated Fetal Weight and UBF (r=078, p<0.0001). When UBF was adjusted for Estimated Fetal Weight, a significant inverse relationship with Gestational age was demonstrated (r=-0 43, p<O 0001) Likewise, a significant inverse relationship existed between Umbilical Artery S/D ratio and UBF (r=-0.52, p<0 0001). CONCLUSION: Umbilical vein flow as a measure of fetal placental blood flow 1) increases with gestational age and fetal weight, 2) decreases as a function of fetal weight with increasing gestation; and 3) decreases with increased placental resistance. These findings are consistent with current understanding of fetal and placental physiology, and suggest that this modality may be a useful tool to estimate fetal placental blood flow in research and clinical practice


133 NORMAL VALUES OF URINARY ALBUMIN AND PROTEIN EXCRETION DURING PREGNANCY Kenneth Higby, Cheryl R. Suiter` John Y. Phelps', Theresa Siler-Khodr', Oded Langer, Dept. of Ob/Gyn, The Univ. of TX Health Science Center at San Antonio, TX and Brooke Army Medical Center, Ft. Sam Houston, TX. OBJECTIVE: To determine the normal 24° excretion values of urinary albumin and total protein in healthy pregnant women. STUDY DESIGN: 228 healthy pregnant women 53S years of age without a history of or subsequent development of pre-eclampsia, hypertension, diabetes mellitus, renal disease or pyelonephritis have been evaluated in an ongoing study. All patients gave informed consent and were given both explicit verbal and written instructions regarding the 24' collection. All patients were tested to ensure absence of a urinary tract infection when specimens were collected. Adequacy of the collection was determined by creatinine excretion. Creatinine was assayed by a modification of the Jaffe reaction, protein by pyrogallol red, and albumin by RIA. All specimens were run in duplicate with the mean value used. RESULTS: The mean protein excretion in 24° was 98.8 mg, upper 9S% confidence limit 261.4 mg. The mean albumin excretion in 24°was 10.3 mg, upper 95% confidence limit 34.4 mg. No patient had evidence of microalbuminuria defined as 24° urinary albumin excretion greater than 30 mg/I. CONCLUSION: This data supports 300 mg/24" of urinary protein as the upper limit of normal during pregnancy. Albumin accounts for a small fraction of total urinary protein excretion.

134 ACCURACY LIMITS OF ULTRASONOGRAPHIC ESTIMATION OF HUMAN FETAL URINARY FLOW RATE. H L. Hedriana, T. R. Moore. Division of Perinatal Medicine, Department of Reproductive Medicine, University of California San Diego, San Diego, CA OBJECTIVE: To define in a controlled setting the accuracy of currently available methods of sonographically estimating human fetal urinary flow rate (FUFR). STUDY DESIGN: 11 demised fetuses were studied In a water bath. Saline was infused into the bladder incrementally to simulate a rate of 1 ml/min. Serial fetal bladder volumes (FBV) were calculated from sonographic measurements using the ovoid formula reported by Campbell et al, Wladimiroff et al, and Rabinowitz et al (OV=4/3*pi"L'W*D/8), and from a sagittal area volume (SAV) formula reported previously by us (SAV=0.463+1.394"SA, SGI 1993) FUFR was determined by 1) by subtracting the mean of two FBVs at the start and end of 30' bladder filling, or 2) regressing 3, 4, and 6 FBV observations against time. The means of FUFR estimates derived with each method were compared to the actual rate of 1 ml/min using the Student t test. RESULTS: The volume subtraction technique using OV yielded FUFR=1.68 ml/min, 95% CI=±48%. Similar rate overprediction occurred using regression with OV (1 38-1.45 ml/hr, 95% Cl=±58- 66%) FUFRs from SAV (0 99-1 02 ml/hr, 95% Cl=i35-39%) were significantly better than those from OV, (p<0.0001) Regression with 3 (95% Cl=±39%) or 4 points (95% CI=t37%) was marginally less accurate than 6 points (95% Cl=±35%, p<0 0001). CONCLUSIONS: Previously reported FUFRs based on the ovoid volume formula overestimate the true rate by 40-70% FUFR calculated by regression of 3 or 4 measurements of the sagittal bladder area against time provide a better estimate of true rate with a superior margin of uncertainty This technique can be used to predict human fetal urinary flow rate with an accuracy of ± 35%

Volume 170, Number 1, Part 2 Am] Obstet Gynecol

135 FETAL ctºIIi IEIA11 . T]I1 IS AM)CIATID WITH AI iIX D FZtCrI 4 cF RR UN P[CUXRG B cßls AND MAY EXPLAIN I NUM d 7SrAN ]}i LATER LIFE. F. A. Van Assche, L. Aerts*, K. Holertrns*, Dept. 08/GYN Leuven/Belgium. Gbjective: We have previously shown in the rat that fetal

goxth retardation and hypoinsulinism induce insufficient stimulation on the insulin receptor in the fetus aid insulin resistance in the adult. In the hurte, RIM is

associated with diseases in adult7iood (Syrxirrn e X). The

morphology and function of huren fetal B cells in IUGR r explain the link between fetal hypoirLadiniEwn and adult insulin resistance. Study design: A morphcmetric study of the endocrine pancreas in 20 human fetuses with IUGR and notmal grauth (C. ). Maternal endocrine disorders were excluded. Reailts: A reduced amiount of endocrine tissue and of B

cells and hypoinsulinism is present in 1UGR (Table, M-S. D. )

Fetal age Weight End-tissue B cells Insulin (weeks) (gran) Pecs. Pert. W/ml

IlXR 34.3i-2.4 1634_278 2.8+0.6 31+5 6.2+0.9

C. 34.6}2.3 2422+284 4.9+1.3 47+7 11+1.7

Car]usian: A reduced amount of B cells is the morphologic basis of hypoinsulinisn in nM. This phearenrn may be

responsible for insulin resistance in later 1if.

136 PLATELET ACTIVATING FACTOR ACETYL HYDROLASE (PAF-AH) ACTIVITY FOLLOWING CHORIONIC VILLUS SAMPLING (CVS) AND

AMNIOCENTESIS. A. A. Saleh. J. M. Johnston, ' P. G. Pryde x N. B. Isada, M. P. Johnson, M. I. Evans, R. J. Sokol. Depts Ob/Gyn, Genetics & Pathology, Grace & Hutzel Hospitals/WSU, Detroit, MI, and Univ Texas Southwestern, Dallas, TX OBJECTIVE: PAF Is essential for embryonic development

and is a potential vasodilator. It increases vascular permeability and stimulates prostaglandin E2 (PGE2)

production. PAF-AH, the enzyme that degrades PAF, is

synthesized by decidual macrophages. The aim of this study was to test the hypothesis that CVS and/or amniocentesis might cause an increase in maternal PAF-AH activity. STUDY DESIGN: Maternal plasma PAF-AH activity was evaluated in women before and after undergoing genetic amniocentesis (n=13) and transcervical CVS (n=29). A control group (n=9) was evaluated to study the effect of venipuncture. RESULTS: CVS caused a significant elevation in PAF-AH activity (the mean different was -2.26,95% Cl was -3.4 to

-1.09, t=3.955, p<0.0001). No changes were noted in PAF-AH activity In the amnio or the control groups. CONCLUSIONS: CVS causes subclinical release of PAF-AH, possibly from decidual macrophages. Increased PAF-AH might result in decreased PAF levels. PAF decrement might lead to vasoconstriction in the placental circulation due to the lack of the vasodilator effects of PAF and possibly PGE2.

SPO Abstracts 315

137 AMNIOTIC FLUID VOLUME DOES NOT PREDICT ADVERSE FETAL OUTCOME IN DIABETES. Chester B. Martin. Jr. Dept. of Ob-Gyn, University of Wisconsin, Madison, W l. Objective: To assess the ability of abnormal amniotic fluid volume (AFV) measurements to predict adverse fetal outcome in diabetic pregnancy. Design: In a prospective observational study, AFV measurements were added to the antepartum fetal assessment protocol of 120 consecutive pregnancies of insulin-requiring diabetics (type 1,43; type 2,12; gestational, 65). Adverse outcomes assessed were operative delivery for fetal distress, low Apgar score (<5 at I min., <7 at 5 min. ) and low umbilical cord blood pü (artery <7.17, vein <7.26). Statistical comparison was by X2 analysis. Results: Adverse fetal outcomes occurred in 22 pregnancies (18%). Pregnancies with only normal AFV measurements (4- quadrant AF index >5 <20 cm, largest vertical column >3 <8 cm) (N=59) accounted for 16 of these (27% adverse outcomes in this group). There were 2 adverse outcomes in 12 pregnancies with I or more low AF measurements (17%), 1 in 9 pregnancies with borderline measurements (AFI >5 <8 cm) (11%) and 1 in 3 pregnancies with both high and low AF measurements (all NS vs. normal AF measurements). There were 3 adverse outcomes in 40 pregnancies with high AF measurements (7.5%) (P=0.015 vs. normal AF measurements). The last test before delivery was low in 3 pregnancies, borderline in 6, normal in 103 and high in 8. There was no relationship between the last AF measurement and fetal outcome. Conclusion: Abnormal AF volume measurements do not identify those diabetic pregnancies at increased risk for adverse fetal outcome.

138 MODIFED FETAL RESPONSE TO VIBRATORY ACOUSTIC STIMULATION ASSOCIATED WITH MATERNAL INTRAVENOUS MAGNESIUM SULFATE THERAPY. David M. Sharer. Tha University

of Roohester School of Medicine and Dentistry. Rochester, Now York. OBJECTIVE: Maternal Intravenous magnesium sulfate (IV MOSO4I therapy has been associated with decreased fetal heart rats (FHR)

variability and reactivity, resulting in an Increased Incidence of nonraaotive nonstren tests, frequently requiring further assessment of fetal well-being. This study was designed to assess fatal response to vibratory sooustio stimulation (VAS) In association with maternal IV MUSO4 therapy. STUDY DESIGN: Five gravides with singleton gestations with normal fetal anatomy, Intact membranes, and normal amniotio fluid volume 2 31 weeks, presenting with pretarm labor were Included. VAS was performed prior and during IV MgSO4 such that each fetus served as its own control. Ultrasound was applied during VAS to assess fetal

movement response. Response to VAS was considered normal if a FHR acceleration of at least 15 bpm for at least 15 seconds occurred within 15 seconds of VAS with prolonged fatal movements. Maternal

serum magnesium levels were obtained prior to each stimulation. RESULTS: All fetal responses prior to treatment were normal. All fetal responses in association with IV MgSOs ware abnormal, consisting of blunted FHR aooeleration@ ranging between 10-15 bpm In amplitude for 10-15 seconds with brief fetal movements. Mean maternal serum magnesium levels I ±SE) during VAS, prior to and following IV M9SO4

were 1.4±0.1 mEgIL and 5.2±0.4 mEgFL. respectively (p=0.008). All five minute Apgar scores were t S. This occurrence may represent an effect of magnesium on the fetus as either a central nervous system depressant or a peripheral neuromuscular relaxant. CONCLUSION: Those results Indicate caution should be exercised In Interpreting fetal response to VAS In the presence of therapeutic maternal magnesium levels.

316 SPO Abstracts

139 BIOPHYSICAL PROFILE TESTING IN HIGH ORDER MULTIPLE GESTATIONS. ll' , H. Finberg'. Phoenix Perinatal Associates and Good Samaritan Regional Medical Center, Phoenix, AZ. OBJECTIVE: To determine the value of biophysical profile (BPP) testing in preventing intrapartum death in patients with high order multiple gestations (triplets or quadruplets). STUDY DESIGN: A retrospective review was performed of patients with triplets and quadruplets delivered between 1988 to 1991. The ultrasound parameters of the BPP score were used without the non-stress test (NST) component due to technical difficulty with that test. A score of 6-8/8 was therefore considered reassuring, 4/8 equivocal, and 0 or 2/8 possibly abnormal. Tests were twice per week. RESULTS: Eighteen patients with triplets and six patients with quads comprise the study group. The last BPP before delivery was evaluated. There were 0 antepartum deaths in these 78 babies. The last BPP score was 2/8 in 9 babies in 5 triplet pregnancies and 2 babies in 1 quadruplet pregnancy. Six pregnancies (25%) were delivered based on BPP results and the clinical situation. There was no morbidity or mortality in the 16 babies delivered because of abnormal BPP testing. CONCLUSIONS: This series produced no stillbirths. Twenty- five percent of these pregnancies eventually delivered for nonreassuring BPP testing with good outcome. The BPP appears to be a reliable antepartum test of fetal well being in triplets and quadruplets.

140 FETAL SMALL VESSEL DOPPLER AS A PREDICTOR OP OUTCOME IN POST-DATES PREGNANCIES. S. Navas. J. A. Molinari, S. Weiner, A. Ludomiraky. Dept. OblGyn, PA Hosp, Phila. PA. OBJECTIVE: To assess whether fetal small vessel Doppler (FSVD) analysis is useful in predicting post-date (PD) pregnancy outcome. STUDY DESIGN: Patients having routine PD testing after 41 weeks were evaluated by Doppler analysis by one examiner. The pulsatility index (PI) of the fetal middle cerebral (MCA). common carotid (CCA), descending aorta, renal, umbilical (UMBA) and maternal uterine (UFA) arteries were obtained. Delivery mode. fetal distress t admission to intensive cam nursery (ICN), meconium stained amniotic fluid (MSAF), cord gases, Apgar scores, sex and birth weight (BW) were analysed. Pearson correlation coefficients, Spearman rank correlations and T-test were used for statistical comparison. RESULTS: 53 patients were evaluated at a mean of 3.3 days prior to delivery (range 0-9). The rates of spontaneous vaginal, operative vaginal and Cesarean (CS) deliveries were 54.7%, 13.2%, 32.1% respectively. Four of the neonates were admitted b the ICN. 11 had fetal distress; 28 had MSAF and 19 of the newborns were female. The following statistically significant correlations between Pis and outcome variables were found the mean CCA PI was lower in CS deliveries(I. 59, SD=0.57) than non CS deliveries (1.99, SD-0.57; pß. 04); the mean UMBA PI in ICN fetuses was higher (0.97, SDO. 30) compared to the remaining babies (0.75, SDc0.19; p=0 04); the mean UTA PI (SD) among fetuses with MSAF was 0.62 (0.19) as compared to 0.44 (0. IS) in deliveries without meconium (p=0.01). There is negative correlation between UMBA P) and the base excess (BE) values (pß. 009), and between the CCA PI and p002 value in arterial cord blood (pcO. 05). Female fetuses had a mean MCA PI which was 15% larger then male (p=0.05). There exists a negative correlation between UMBA PI and BW (p<0.05). CONCLUSIONS: These positive correlations suggest that them may be a place for FSVD in the management of PD pregnancies.

January 1994 Am f Obstet Gynecol

141 CHANGING OBSTETRIC OUTCOMES IN LETHAL CHROMOSOMAL ANEUPLOIDY. T. Westover. E. Guzman, D. Day-Salvatore' Dept. of MFM. UMDNJ-RWJ Mod School, New Brunswick, New Jersey. OBJECTIVE: In the early 1980's, a number of US and British Investigators reported caesarean section rates for singleton trisomy 18 Infants of approximately 55%. Greater than 85% of these cesareans were performed secondary to fetal Indications. We hypothesized that modem prenatal diagnostic techniques such as high resolution ultrasound and maternal biochemical screening would detect the vast majority of lethal chromosomal aneuploldy and result In significant Increases In the frequency of conservative obstetric management as compared to the above historical controls. STUDY DESIGN: We retrospectively reviewed our cylogenetics log book for the years 1988-mid 1993 and correlated any lethal singleton aneuploidies (trisomy 13,18 and triploidy) with a computerized medical records search to examine the pennatal course and outcome of these infants. The cesarean rate of our modem cohort was compared with the previously published data using two tailed Fisher's exact test. RESULTS: All 33 infants diagnosed In the first or second trimester were previable (<24 weeks), were detected at amniocentesis/CVS performed for advanced maternal age, abnormal ultrasound, or abnormal AFP, and underwent termination of pregnancy. All 8 Infants diagnosed in the third trimester (4) or postnatally (4) could have been diagnosed in the second trimester since all had at least one major malformation easily detected on level 11 ultrasound or had abnormal AFP. All four Infants diagnosed post natally should have been diagnosed In the antepartum period since obstetric conditions mandating ultrasound evaluation developed In all four; polyhydramnlos, preeclampsia, IUGR, or breech presentation. The overall cesarean section rate was 5% (2/41). This C/S rate was significantly less than the historical controls (P<. 01). CONCLUSION: This data suggests that modem prenatal diagnosis will detect the vast majority of lethal aneuploidy In the antepartum period and allow for conservative obstetrical management.

142 INTRAUTERINE GROWTH RETARDATION: CONTRACTION STRESS TEST OR BIOPHYSICAL PROFILE? M Lion, MP Nageotte, CV Towers, M deVeciana, JS Toohey. University of California at Irvine, Long Beach Memorial Medical Center, Long Beach, CA

OBJECTIVE: To compare the contraction stress test (CST) end the biophysical profile (EPP) as a back-up test for patients with a clinical diagnosis of intrauterine growth retardation (IUGR) who have an equivocal nonstress test/amniotic fluid index (NST/AFI). STUDY DESIGN: Date collected in a prospective randomized study was retrospectively analyzed. The testing protocol consisted of twice weekly NST/AFIa. Patients with equivocal tests randomized to a CST or BPP back- up group and remained in that group for the rest of the pregnancy. Inclusion criteria for analysis: (1) IUGR as the only indication for testing, (2) singleton gestation, (3) 2 32 weeks at first test, and (4) equivocal NST/AFI randomized to CST or BPP. The CST and BPP groups were compared for interventions for an abnormal CSTIBPP, cesarean sections, and adverse neonatal outcomes (birth weight < 10%ile, 5 minute Apgar < 7, neonatal Intensive care unit admission, stillbirth or neonatal demise). Sensitivity and specificity of the CST and BPP for adverse neonatal outcomes were calculated by evaluating interventions for abnormal tests. RESULTS:

CST (n-56) Opp In-58) I

EGA at delivery (weeks) 39.1 t 1.7 39.1 t 1.8 NS Birth weight (grams) 2792 ± 638.4 2797 t 552.8 NS 'Intervention for abnorme) test 17/56 (30.4%) 4/58 (6.9%) p=. 003 Cesarean sections 16156(29%) 11/58 (19%) NS Birth weight < 10%ils 8/58 114.3%) 12/58 120.7%) NS Adverse neonatal outcome 8/56 (14.3%) 13158 122.4%) NS Sensitivity, specificity 88%, 79% 17%, 96%

CONCLUSION: Although CSTs result in higher intervention rates, they are much more sensitive for adverse neonatal outcomes than BPPs when used as beck-up tests in patients with a clinical diagnosis of IUGR.

Volume 170, Number 1, Part 2 Am. ) Obstet Gynecol

143 ANTENATAL FETAL SURVEILLANCE IN PREGNANCIES COMPLICATED BY FETAL VENTRAL WALL DEFECTS. Cerr MN", Asrat T, Towers CV, Nageotte MP, Freeman RK. University of California, Irvine Medical Center, Orange, CA and Long Beach Memorial Medical Center, Long Beach, CA. OBJECTIVE: To evaluate the need for antenatal fetal surveillance in pregnancies with known fetal ventral watt defects (VWD), since this issue has not been adequately addressed in the literature to date. STUDY DESIGN: A case control study was conducted of all inborn karyotypicalty normal fetuses with VWD's between 1/81 and 7/93. Antenatal and postnatal data from Vl cases were compared to postdates (PD) pregnancies. RESULTS: 56 cases of VW's (42 with gastroschisis and 14 with osphalocete) and 824 PD pregnancies were reviewed and compared. The mean age, gravidity and parity were similar in both groups. The incidence of antenatal abnormal fetal surveillance tests was significantly higher in the VIA group compared to the PD

group (58.9% vs 34.5%, ft=2.7, pmO. 0001). 41.1% of VWD cases versus 10.7% of PD cases required pregnancy intervention for

abnormal fetal surveillance tests (OR-5.8, p"0.0001). 28% of VWD cases versus 5.7% of PD cases had cesarean sections performed for fetal distress (OR=6.6, p-0.0001). The earliest delivery for fetal distress occurred at 27 weeks. IUGR

occurred in 30.4% of VWD cases and 1.6% of postdates cases (OR=27.2, p-0.000l). One stillbirth occurred in each group (at 31 weeks vs 42 weeks) (p=NS). Low Apgar scores at five minutes were reported more frequently in the VWD group (7.1%) than in

the PD group (0.9%) (OR-9.0, p-0.0001). There were four

neonatal deaths in the VWD group and none in the PD group (p=0.0001). CONCLUSIONS: (1) Pregnancies complicated by ventral wall defects are at significantly increased risk for antenatal compromise. (2) Fetuses with ventral wall defects also have a marked increase in the incidence of IUGR. (3) Since the earliest intervention for fetal distress occurred at 27 weeks and a stillbirth occurred at 31 weeks, we recommend initiating antenatal fetal surveillance at fetal viability.

144 THE IMPACT OF TRANSDUCER ORIENTATION UPON 111E AMNIOTIC FLUID INDEX. Thomas H. Strong. Jr.. M"D. " Glen S. Lovelace, M. W Phoenix Perinatal Associates - Good Samaritan Regional Medical Center, Phoenix, Arizona. OBJECTIVE: To determine the Impact of the orientation of the ultrasound transducer upon the amniotic fluid index (AFI). STUDY DESIGN: Fifty consecutive gravidas received the standard AFI assessment with the ultrasound transducer held in

a longitudinal plane as stipulated by the creators- of the technique. A 'modified' AFI was also obtained with the transducer held transversely. For both techniques, each amniotic fluid pocket was selected by a single observer blinded to the actual measured depth of the pocket. The fluid pocket selected was measured by another observer blinded to the transducer's orientation. Linear regression analysis was used to compare the two AFI techniques. RESULTS: A correlation coefficient (R) of 0.98 was noted. The regression equation was: modified API - 0.52 + 0.98 x standard AFL The mean difference between the techniques was 0.92 ± 0.77 cm. Thirty-three (66%) had a difference between the two techniques of <1 cm and 45 (90%) had a difference < 2 cm. CONCLUSION, The two-dimensional orientation of the

ultrasound transducer does not appear to impact upon API

assessment.

SPO Abstracts 317

145 IS UNEXPLAINED LOW MATERNAL SERUM ALPHAFETO PROTEIN INDICATOR OF GESTATIONAL DIABETES OR

R. -}jomsiS.

Didolkar. The Union Memorial Hosp. Baltimore MD. OBJECTIVE: To establish significance of unexplained low Maternal Serum Alpha- Fetoprotein (MS-AFP) and compare outcome between high and low MS-AFP with or without pre-existing risk factors. STUDY DESIGN: All patients referred to Prena- tal Genetics Lab between Jan 1990 and Dec 1992 for abnormal MS-AFP were reviewed. 78 patients with abnormal MS-AFP and normal chromosomes were compared to 58 patients with normal MS-AFP, who were selected randomly from same population and time period and divided into 3 groups: I-Unexplained low MS- AFP (<0.4 MOM) II-Unexplained high MS-AFP (>2.0 MOM) III-Normal MS-AFP. Patients' char-

ts were reviewed retrospectively for pre- existing high risk factors and current pregnancy outcome. Chi-Square analysis was used. RESULTS: There was no difference in the three groups regarding age, parity and race, although women In Group II delivered at an early GA-36.3 wks vs 38.3 wks (III) and 39.1 wks (I) )P<0.005) Group I showed statistically significant difference in H/O macrosomla, G. dlabetes, miscarriages. During the current pregnancy, Group I had higher incidence of LGA/macrosomia 23.4% vs 3.22% (Group II) and 8.62% in Group III (P<0.0S). As expected, Group II was significant for IUGR, PIH, PTL, PROM. CONCLUSIONS: Unexplained low MS-AFP was associated with increased incidence of macrosomla, G. dlabetee and fetal distress, while high MS-AFP was associated with higher incidence of PROM, PTL, PIH, IUGR.

146 VARIABLE DECELERATIONS DURING NONSTRESS TESTS. CLINICAL ASSOCIATIONS. T. Tharakan. V. DiBella", L. V. Baxi. Columbia University, College of Physicians and Surgeons, Columbia Presbyterian Medical Center, New York, NY. OBJECTIVE: To determine the clinical associations of variable decelerations during nonatress tests (NSTs) with amniotic fluid volume, intrapartum complications and perinatal outcome. STUDY DESIGN: Patients with singleton pregnancies and intact

membranes undergoing NSTs from January 1993 onwards were enrolled in this ongoing study. NSTs were prospectively evaluated for reactivity and the presence of decelerations, and results of Amniotic Fluid Volume (AFV) and Biophysical score (BPP) were recorded. Intrapartum data and perinatal outcomes were recorded. Patients/tests were divided into 3 groups -1) one or more tests showing variable decelerations (83/253); 2) variable decelerations and in addition, at least one suspicious or minimally reactive test (31/202), 3) controls-all NSTs reactive (109/239). RESULTS: To date, 223 patients undergoing 694 NSTs were evaluated. The mean (± SD) gestational age at last NST and at delivery were 38.44 (±2.95) and 39.7 (±2 03) weeks, respectively. Neither Group I or 2 showed a significant increase in the incidence of abnormal AFV or BPP, small for gestational age infants, or low I or S min Apgar scores. Patients in Group 2 had significantly more cord complications (p <. 005), operative deliveries (p=. 012), emergency operative delivery for fetal compromise (p<. 001). When 513 tests performed within 7 days of delivery were analyzed separately, similar results were obtained. In addition, in this subgroup Group 2 had increased incidence of low 1 minute Apgar scores (p <. 05). CONCLUSIONS: Variable decelerations are associated with increased intrapartum complications and adverse perinatal outcome only when accompanied by minimally reactive or suspicious tracings.

318 SPO Abstracts

147 WHY ARE WE STILL USING THE FETAL BIOPHYSICAL PROFILE? 0�S x, M. Belfortx, L. Knudsen', R. Vidal', K. Moise. Dept. Ob/Gyn, Baylor College of Medicine, Houston, TX. OBJECTIVE: To determine whether the fetal biophysical profile (BPP) may be replaced by a simpler and less time consuming antepartum test. STUDY DESIGN: For the last 3 years, the BPP has been used as the primary test of fetal well-being at our center. All the examinations were performed by one of two ultrasound technicians. The patient population consisted of women referred from outlying clinics to the tertiary care center because of a high risk pregnancy. The examination and scoring criteria followed the method of Manning except for the amniotic fluid component. Instead of measuring a single pocket, the amniotic fluid index (AF[) was determined and a score of zero given in cases where the AFI was below the 5 percentile for gestation. The 95% limits published by Moore (1990) were used for reference. The results of the examinations and the patients' data were entered into a computerized database and were reviewed retrospectively. All those with scores of 6 or less on a scale of 8 were identified. RESULTS: 4022 BPP examinations were performed in 590 patients. 250 examinations had a score of 6 or less. Of these, only 19 examinations had a score of 2 for the amniotic fluid component of the BPP. The sensitivity and specificity of a decreased AFI in predicting a BPP of 6 or less is 92.4 and 100 "/., respectively. Only 6 examinations had a score of 4 or less, all of whom had a normal AFI. Four of these patients however had maternal perception of decreased fetal movements (FM). Using a normal AFI together with maternal perception of adequate fetal movements as a test of fetal well-being would have resulted in the failure to identify 2 fetuses with a BPP score of 4 or less. In the worst case scenario, this would have increased the perinatal mortality rate by 3/1,000 births. CONCLUSION: Measurement of the amniotic fluid volume appears to be a valuable screening test. Together with the maternal evaluation of fetal movements it represents a simpler and more cost-effective alternative to the biophysical profile for antepartum fetal monitoring.

148 DISTANCE FROM THE VERTEX AS A FACTOR AFFECTING INTRAUTERINE SOUND PRESSURE LEVELS PRODUCED BY VAST. J- Scarit, D. Eher, A. Kleid A. Dilliod, ̀ S. Stramdf. Dept. OB/GYN, Medical University of SC, Charleston, SC OBJECTIVE: The overall sound pressure level (SPL) produced by VAST has been measured as high as 135 dB (Gerhardt, 1990). The purpose of this study was to determine intrauterine sound pressure levels produced by the VAST at specific distances from an intrauterine hydrophone in human parturients. STUDY DESIGN: Measurements of intrauterine sound were taken in 9 volunteer parturients in normal active phase labor. After informed consent and rupture of the membranes with clear fluid, an intrauterine hydrophone (Sparton) was placed transcervically near the fetal neck. Ultrasound was used to confirm the location of the fetal hydrophone and to determine amniotic fluid volume. VAST was performed on the maternal abdomen directly over the fetal hydrophone and at 5.10,15, 20, and 25 cm. increments from the hydrophone, as well as at the maternal sternum. The hydrophone amplifier output was stored on a calibrated audio tape recorder for later off-line analysis. RESULTS:

CONCLUSION: SPLa produced by VAST at sites up to 23 cm. from the fetal vertex may minimize fetal sound and vibratory exposure and still allow for an effective test.


149 LONGITUDINAL AMNIOTIC FLUID INDEX IN TERM PREGNANCIES COMPLICATED BY OUGOHYDRAMNIOS D. Wind, A. Fishman and R. Paul. LAC+USC Medical Center, Los Angeles, CA. NULL HYPOTHESIS: There is no difference in the penultimate amniotic SAL index (AR) in pregnancies destined to develop digdrydrarmne (defined as an AR of < 5.0 cm) compared to the AR values for normal pregnancies as defined by Moore and Cayle (Am J Obatet Gynecol 162: 1168). METHODS AND MATERIALS: Duii g the study period of one year (January 1992 throw December 1992), 11827 aMepartu n surveil. lance tests were performed on 3378 patients. Of these patients, 576 were found to have AR's < 5.0 cm. Of these 576 patients, 265 delivered fiter 38 weeks had serial biweekly nonstress tests and amniotic fluid index measurements. The amniotic fluid index was measured in the manner described by Phelan at all (J Reprod Med 32: 540). The penultimate AFl measurements were stratified based on estimated gestational age and compared to the values defined by Moore and Cayle. RESULTS:

EGA (wks) n USC Mean USC AR Mean Afl by Pendtimeie AR Range(an) Moore & Cayle

36 17 9.3cm 5.2-15.7 13.8cm 37 23 8.9cm 5.5 - iL0 13.5cm 38 22 7.7cm 5.7-10.7 13.2cm 39 34 9.1cm 5.2-13.7 12.7cm 40 30 9.0cm 5.1-20.3 12.3cm 41 69 8.5cm 4.7-15.3 11.6cm 42 50 9.0cm 4.2 - 16.8 11.0cm

At each EGA tested, the mean penultimate AR (cm) differed significantly (p < 0.05) (tom the mean AR value fora normal gestation as delineated by Moore and Cayle. The mean penultimate AR also differed significantly from similar values for matched controls. CONCLUSIONS: There is a significant difference between the penultimate AR for pregnancies complicated by oligohydramnios arid the normal AR value as detem*ied by Moore and Cayle.

150 INCREASE IN AMBIENT TEMPERATURE CAN EXPLAIN DECREASE IN AMNIOTIC FLUID INDEX (AFI). A. Scisclone! K. Costigan, " T. Johnson, Dept. Oyn/Ob, The Johns Hopkins Univ. Sch. of Md.. Baltimore, MD. OBJECTIVE: In the third trimester, the AFI may be affected by maternal fkiid status. As the ambient temperature Inaesses, there Is an increase in Insensible fluid loss and the potential for dehydration. We hypothesize that as temperature increases there would be a concomitant decree. 0 in AFI. STUDY DESIGN: From June 11 to August 16,1993,42 women with singleton pregnancies between 27 and 40 weeks gestation undergoing serial antenatal testing had AFI determinations recorded at least weekly. The daily high ambient temperature In our urban area was subsequently obtained. A 2.3. and 4-day mean temperature prior to the test date was compared to API using a Spearman-Rank Correlation. RESULTS: The daily high temperature ranged from 71 "F to 104"F and AFI values ranged from 1.7 to 24.7 em during the study period. There was a significant correlation between the 2.3 and 4-day mean temperature and AFI, with the four-day mean being the most significant Cr " -0.307, p<0.00011. This effect wes most pronounced In patients with Systemic Lupus Erythematosus.

s "f ,

HMM" NO /N tam

CONCLUSIONS: Fluctuations in ambient temperature are inversely correlated to changes in AFI. This relationship should be taken into account when interpreting the API as a measure of fetal well-being.


151 THE SIGNIFICANCE OF UNSOLICITED PATIENT COMPLAINTS OF DECREASED FETAL MOVEMENT

J Weeks, MD, J Perlow, MD, T Asrat and C Towers, MD Dept OB/GYN University of Louisville, Long Beach Memorial &UC Irvine Medical

Centers Objective: To determine the likelihood of fetal death, or need for immediate delivery following a solely patient initiated visit (i. e. without physician prompting or solicitation) for decreased fetal movement. Study design: A cohort study of patients (n=258) who presented from their homes, directly to labor & delivery with complaints of decreased fetal movement (DFM) from 5/1/89 to 3/30/93. AU study patients presented beyond 20 wks gestation Patients seen for DFM in the antepartum testing center from 1/1/81 to 12/30/90 served as historical controls (n=970). The majority of controls presented after being questioned about fetal activity in their physicians office. Patients were labeled as "high risk" in the presence of medical complications or indications for antepartum testing other than DFM Results: While there were no fetal deaths among patients seen for DFM in the antepartum testing center, 10 fetal deaths were diagnosed in the study group for an overall fetal death rate of 39 per 1000. Patients who independently presented for DFM were significantly more likely to have a fetal death regardless of risk status (table 1) Immediate Cesarean delivery occurred with equal frequency in the study and control groups.

L0r RISKI HIGH RISK

table I study controls p study controls p X2 (n-224) (n=679) (n=34) (n{291)

IUFD 7 0 <. 001 3 0 <. 01 31% 88%

urgent 4 11 0.77 - - - C/S 18% 16%

Conclusion: Patients who independently report to labor & ceuvery Tor DFM are significantly more likely to have a dead fetus than those who are referred to an antepartum testing center Nearly 2% of all patients with DFM will have evidence of evolving fetal compromise.

152 OLIGOHYDRAMNIOS IN THE TERM GESTATION: AT WHAT LEVEL SHOULD INTERVENTION OCCUR? MC Treadwell. U Stacksx, SF Bottoms. Wayne State University/Hutzel Hospital, Detroit, MI OBJECTIVE: Gestational age specific nomograms have been established to define abnormal fluid volumes utilizing amniotic fluid index (AFI). The purpose of this study is to clarify the lower limit of AFI associated with increased morbidity in the term gestation. STUDY DESIGN: We evaluated 2662 anatomically normal singleton pregnancies undergoing ultrasound determination of amniotic fluid volume and delivering beyond 37 weeks gestation. Stepwise logistic regression analysis was performed to examine the relationship between AFI and morbidity, including NICU admission, primary cesarean section, and stillbirth rates. RESULTS: The only neonatal or maternal outcome measure significantly correlated with AFI was NICU admission. When analyzed at 5mm increments, there was an increased incidence of NICU admissions with AFI 5 45mm. No increase in morbidity was apparent at higher fluid volumes. CONCLUSIONS: Our findings support using an AFI<50mm as criteria for obstetrical intervention. Arbitrary use of the fifth centile for gestational age or AFI cutoffs of 560 to 80mm to Identify patients requiring immediate delivery in the absence of other factors may result in an unnecessary number of inductions.

SPO Abstracts 319

153 FACTORS INFLUENCING MATERNAL PERCEPTION OF FETAL MOVEMENT IN THE COUNT-TO-TEN SYSTEM. )jj,

rn TR Moore. Division of Perinatal Medicine, University of California San Diego, San Diego, CA. OBJECTIVE: To determine which factors assessed in the modified biophysical profile (mBPP=NST+AFI) are associated with decreased or absent fetal movement. STUDY DESIGN: 192 patients undergoing antenatal fetal testing with the mBPP also performed daily fetal movement assessment by recording the time to appreciate ten fetal movements (fetal movement times - FMT). The mean FMT was correlated with mBPP test results and certain other factors Including placental position and IUGR/macrosomia. A subgroup of 12 patients with absent fetal movements was analyzed separately. RESULTS: The mean i SD FMT of patients with IUGR (14±2 min) or macrosomia (16±2 min) was longer than In normals (11±2 min, p=0.004). Although the FMTs associated with anterior placentation (31±2 vs 8±2 min), NR NST (13±2 vs 11±2 min) and AFK5cm (13±2 vs 8±2 min) were prolonged compared to patients with a normal result, none were individually statistically significant. However, the multiple regression correlation between FMT and these 3 factors was highly significant (p=. 027). Among patients with absent fetal movement, NR NST was three times more likely (19% vs 6%, p=0.001), and were 1.5 times more likely to have anterior placentation than normal FMT (57% vs 37%, p=0.02). CONCLUSIONS: Abnormal fetal biophysical testing is associated with prolonged FMT. Although the combination of low AFI and anterior placentation adversely affects maternal perception of fetal activity, the associated increase in NR NSTs requires comprehensive investigation when FMT is prolonged or movements are absent.

154 MAGNETIC RESONANCE SPECTROSCOPY DETECTABLE CHANGES IN AMNIOTIC FLUID ASSOCIATED WITH OPEN NEURAL TUBE DEFECTS. S. J. Sims. D. T. FujitoX, D. R. BurholtX, D. A. WilkinsonX. Dept. Ob/Gyn, Medical College of Pennsylvania/Allegheny Campus, Pittsburgh, PA. OBJECTIVE: This study was designed to evaluate magnetic resonance spectroscopy (MRS) as a means of detecting biochemical differences between normal amniotic fluid (AF) and AF from pregnancies with open neural tube defects (NTD). STUDY DESIGN: Proton spectra were obtained at 300 MHz on 40 normal and 10 NTD second trimester AF samples. MRS peaks were Integrated and compared with the size of a reference peak to obtain concentration estimates. Differences between the two study groups were analysed using t-tests and the method of principal components. RESULTS: Nine low molecular weight metabolites (acetate, alanine, citrate, creatinine, glucose, histidine, lactate, tyrosine, and valine) were detected and quantitated using MRS. Of these, acetate, creatinine, glucose, and histidine were found to have mean values that were statistically different (p<. 05) between normal control and NTD AF. Acetate levels were higher while creatinine, glucose, and histidine levels were lower in NTD samples. Differences between normal and NTD AF were visualized using star plots based on 2 principal components. CONCLUSIONS: Proton MRS is capable of detecting differences in concentrations of biochemical constituents between normal and NTD AF. This suggests that MRS could be useful in t4 .v for prenatal diagnosis.

320 SPO Abstracts

155 DETZRMXIUTIOA OF FLTA WELLBEING IN TWIN os STATION ST DOIPnn VLGOCI: K=T, IIONBTRZ8I TESTING. AM 8OUDGRAPYIC GROf1I. ES Kim. MD, x CS Croon MD, LD Devoe, MD. Dept OBGYN, Medical College of Georgia, Augusta GA. OEJECTIVR: To ccmpare Doppler velocimstry of umbilical arteries(S, D ratio), simultaneous nenstress tests (NSTs) and ultrasonographic growth curves (UGC*) to assess individual fetal status in 3rd trimester twin gestation. STUDY DtiIGMt 90 twin pairs (28-40 weeks gestation) received weekly 8: D ratios (continuous wave Doppler), LASTS and AMVs. UGCS were updated every 3-4 weeks. Twins were discordant if estimated weights (LPWs) differed > 20%, and growth-retarded (IOGR) if LFNs fell below the 5thlile for singletons. Only test data that could be consistently assigned to the same twin in each pair were analyzed. Poor outcomes included perinatal mortality, fetal distress, neonatal mixed or metabolic acidosis and It. Comparisons used chi-squared or t-tests. RESULTS: Test correlations with all poor outcomes are shown below as percentages; anomalous twins are excluded.

Sensitivity Scecificity +Pred Value -Prod Value NST 32 94 59 84 Arv 16 97 56 81 Doppler 32 95 63 84 WC 29 94 54 84 Jul tests 52 85 46 87 Doppler 8: D ratios and UCGs yielded equivalent and superior prediction of IUGR and discordancy; NSTs gave better prediction of acute fetal distress and acidosis. CONCLUSIONS: Surveillance of third trimester twin gestation is best served by a combined testing approach. Doppler and UCG re useful in screening for growth disturbance which, in turn, is associated with the vest majority of perinatal morbidity not attributable to anomalies or prematurity.

156 77IE IDENTIFICATION OF A PLURIPOTENT SUBSET OF CD34+ CELLS IN HUMAN UMBILICAL CORD BLOOD. 9, L. Cet

, M. D'Alton, D. W. Bianchi! C. L. Cetrulo, Jr; rM. A. DeMaria, T. J. VadnaisxDept. Ob/Gyn, Div. Maternal/Fetal Medicine, Tufts University, New England Medical Center Boston, MA. OBJECTIVE: To identify, in cord blood, a pluripotent subset population of CD34+ cells (CD34+, CD38-, HLADR-) that has been shown to be capable of reconstitution of both the haematopoictie microenvironment (stromal cells) and haematopoictic stem cells. STUDY DESIGN: Haematopoietie stem cells have been previously identified and enriched using the CQ34+ bone marrow progenitor cell marker. This study was designed to identify CD34+ non- lineage committed cells- particularly CD34+, CD39-, HLADR- cells- which have been shown to be capable of both self-renewal and differentiation along a variety of haematopoietic lineages (Huang, Terstappen, Nature. Vol. 360,24/31, Dec. '92). Cord blood samples (n-10) were collected from deliveries at varying gestational ages (range a 26-40 wks) and analyzed by flow cytometry, alter immunofluorescent labelling with monoclonal antibodies. RESULTS: The CD34+. CD39-, HLADR- population was identified in every cord blood sample, with percentages ranging from 0.01% - 0.05%. CONCLUSION: We have identified, in cord blood, a circulating CD34+, CD38, HLADR- subset population that has previously been shown in fetal bone marrow to possess full haematopoietic reconstitutive ability. These results suggest the possibility of cryopreservation of small volumes of cord blood for later use as an alternative or adjunct to autogenie and/or allogenic bone marrow transplantation.


157 ABSENCE OF RELAXATION TO LACTATE IN HUMAN PLACENTAL VESSELS OF PREECLAMPTICS. R. Figueroa, E. Martinezx, R. P. Fayngershx, L. A. Bracero, N. Tejani, M. S. Wolin'. Depts. Physiol. & Ob/Gyn, New York Medical College, Valhalla, NY. OBJECTIVE: To determine if the observed relaxation to lactate and other agents in placental vessels of normal (N) pregnancies is altered in preeclampsia (P). STUDY DESIGN: Isolated placental vessels (1-2 mm diameter) from N and P pregnancies, incubated under 57* 02 and precontracted with 1-3 µM PGF2a were exposed to lactate (1-10 mM), arachidonic acid (10 nM-10 µM), nitroglycerin (1 nM-1 uM) or forskolin (10 nM-10 µM). T-test statistics were used. RESULTS: Relaxation to lactate was inhibited (p<0.05) in both arteries (A, n=6) and veins (V, n=7) in P vs. N (e. g. @5 mM lactate: N-A =54±2%, N-V = 68±1.4%, P-A = 3.4±1.5%, P-V = -9.9±1.7%), whereas, responses to the other relaxing agents were not altered in the P vessels. CONCLUSION: In preeclampsia, absence of lactate- induced dilation of placental vessels may contribute to the fetal complications associated with vasospasm.

158 UMBILICAL CORD BLOOD CASES: THE EFFECT OF SMOKING ON DELAYED SAMPLING FROM THE PLACENTA. Meyer BA

, Thorp JA, Cohen GR, Yeast JD. Univ of MO 0 KC - St. Luke's Hospital; Kansas City, MO. 64111. OBJECTIVE: to evaluate the effect of maternal smoking on changes in acid-base status with delayed sampling of blood from placental vessels. STUDY DESIGN: Placentas from 40 term, uncomplicated vaginal deliveries with clear amniotic fluid were examined. 22 non-smoking and 13 maternal smokers were evaluated. Arterial and venous cord blood gases and hemoglobins were drawn at the time of delivery, and from their respective placental plate vessels at 30 and 60 minutes following delivery. Statistical analysis was performed with two-way analysis of variance. Data are mean t SD. RESULTS: There were no differences in hemoglobin concentrations at any time during the study. *p<0.05 vs. Non-smoking.

PH P02 pCO2 HCO3 Bass Defic*

DELIVERY: Non-Smoking 7281.05 18.4172 49.8: 6.1 24.0± 1.4 3.1: 1.9

Smoking 7.30:. 05 19.0: 6.3 48.1: 72 24.0: 12 2.8: 2.4

30 MINUTES: Noo-Smokirp 7.20:. 06 15.8: 3.9 55.2: 9.6 22.4: 2.1 6.6123 Smoking 713:. 10' 14.0: 5.0 70.1 t 20.6* 229: 1.9 8.6: 29'

60 MINUTES: Non-Smoking 7.10:. 11 13.8: 4.0 70.6: 17.5 20.8: 2.1 9.9: 4.1 Smoking 6.94:. 10' 11.8: 2.8' 94.0±31.0' 19.1: 4.0' 17.2: 4.6'

venous DIooa gases were slmnarry aunrea. CONCLUSION: In the 60 minutes after delivery: 1) there is significant deterioration in the acid-base status of blood drawn from placental vessels, 2) there is significantly greater deterioration in the acid-base status of smokers compared to non-smokers.

Volume 170, Number 1, Part 2 Am

.1 Obstes Gynecol

159 MID-TRIMESTER PLACENTAL VOLUMES PREDICT BIRTHWEIGHT AT TERM IF Clapp', K. Rizk', J Crass` Depts. of Ob/Gyn and Radiology, Metrofealth Med. Ctr and Case Western Reserve University, Cleveland, OH. OBJECTIVE: To test the hypothesis that mid-trimester placental growth is

a major determinant of size at birth in active women STUDY DESIGN: Three serial measurements of placental volume were obtained between the 10 and 26° gestational week of an accurately dated

singleton pregnancy in 35 women who maintained a regular exercise regimen throughout pregnancy. Following standard fetal morphometry, a fixed base, articulated arm, 35 MHz B-mode transducer was used to obtain parallel images of the placenta at 1 cm intervals and placental volume was then calculated using the rectangular rule. The method has a precision of t 5%. Trimmed, drained placental volume and birthweight were obtained at delivery and corrected for sex and gestational age using institutional

normative criteria. Data were analyzed using ANOVA and least squares regression. RESULTS: Placental volumes increased from (meantsd) 132±37 cc to 247±70 cc and 381x96 cc at 16,20, and 24 weeks gestation with an average growth rate of 31*9 cctweek over this time interval. At term, fresh

placental volumes (4511118 cc) ranged between 304 and 823 cc and birthweight (33061453 gm) ranged between 2620 and 4355 gm. Significant

linear correlations (r >. 6500) were present at all time points between

placental volume and birthweight. At 20 and 24 weeks gestation and at term

the r values between placental volume and corrected birthweight were

. 8441, . 8798 and . 8526 respectively and the correlation between the mid-

tnmester growth rate in placental volume and birthwezght was 8778. In

contrast the correlations between the fetal morphometric cenule in the mid- tnmester and at birth were poor in this populace (r <4000). CONCLUSION: In physically active women mid-trimester placental volumes are superior to fetal morphometry in predicting size at birth over a

wide range of birthweight. Supported by NIH grants HD21268 and HD211089.

1(0 AMNIOTIC FLUID ALPHA FETOPROTEIN IAFAFP) AND MATERNAL SERUM ALPHA FETOPROTEIN IMSAFPI IN ABDOMINAL PREGNANCIES: CORRELATION WITH EXTENT AND SITE OF

PLACENTAL IMPLANTATION AND CLINICAL IMPLICATIONS. ýL Shumwev. J. Greenspoon, L. Platt, K. Blakemore, Cedars Sinai Mod

Ctr Los Angeles, CA, Johns Hopkins Univ., Baltimore, MD.

OBJECTIVE: The hypotheses are that in abdominal pregnancies 1)

elevated MSAFP Is due to an altered maternal/ placental interface,

and 2) differences in MSAFP levels may reflect placental location

within the maternal peritoneal cavity. STUDY DESIGN: A review of 1193 ectopic pregnancies from 1983-

1993 revealed 3 cases of abdominal pregnancy. A second trimester

genetic amniocentesis had been performed with AFAFP and karyotype data available in each case. Antepartum, peripartum, and

postpartum clinical courses were analyzed. Placental location was

recorded in each case. RESULTS: MSAFP was elevated in two of the three cases (3.63 and 4.88 MoM). AFAFP was normal in all three cases. No case had an

antenatal diagnosis of abdominal pregnancy. Delivery occurred at 18,19 and 37 weeks. The two cases associated with elevated MSAFP had placentation involving both the bowel and uterus. The

case with normal MSAFP was implanted on the right uterine cornua. AN three cases had a normal karyotype. The two cases with elevated MSAFP had increased maternal morbidity (intrsoperative difficulty,

increased blood loss, and greater length of stay). CONCLUSION: 11 An unexplained elevated MSAFP with normal AFAFP and normal fetal anatomy should alert the clinician to the

possibility of on abdominal pregnancy. 2) Those abdominal

pregnancies with elevated MSAFP appear to have more extensive

placental involvement of the abdominal viscera generate an increased

maternal-fetal circulatory interface; this can account for the elevated MSAFP vslu6s given the normal AFAFP. 3) Those abdominal

pregnancies with elevated MSAFP may have greater maternal

morbidity.

SPO Abstracts 321

161 THE CORRELATION BETWEEN PLACENTAL HISTOLOGIC CHANGES AND HUMAN CHORIONIC GONADOTROPIN IN SMOKERS. M Fenoughtyx, HL Brown. Departments of Ob/Gyn and Pediatric Patholo gy, Indiana University, Indianapolis, IN. OBJECTIVE: To compare placental histologic changes seen In smokers with levels of Human Chorionic Gonadotrophin (HCG) and infant growth status. STUDY DESIGN: Thirty five women demonstrating a sonographic Grade 2 or 3 placenta between 36 to 40 weeks gestation and delivering between 37-41 weeks were included. Women were divided by smoking (n=20) and nonsmoking (n=15) status and infant birthwelght, growth retardation (IUGR) and average for gestation (AGA). The maternal HCG and placentas of 12 AGA and 8 IUGR infants of smokers and 10 AGA and 5 IUGR Infants of nonsmokers were compared for histologic changes including fibrin deposition (FD) szyncytial knots (SK) > 40°/a, and villitis and thrombosis. Analysis was by X and Fishers exact and 'C test where appropriate. RESULTS: Mean infant birthweight, placental weight, and volume for smokers and nonsmokers were not significantly different. HCG levels in smokers and nonsmokers were not significantly different and there was also no significant difference In HCG levels for the AGA and IUGR infants of smokers and nonsmokers. Fibrin deposition was associated with a significantly higher HCG level (no FD = 15028±7916 vs FD = 21662±5279) overall and in nonsmokers (no fibrin = 14434±7096 vs fibrin 22,425±4855) p< . 05. There was no significant difference in HCG levels and FD in smokers and no difference in SK or villitis for smokers and nonsmokers. Unlike previous studies thrombosis and infarction were not histologically apparent in the placentas of smokers whereas these findings were present in nonsmokers. There was no significant relationship between histologic variables and IUGR. CONCLUSIONS: No specific histologic placental changes or hormonal levels as assessed by HCG are consistently found in smokers versus nonsmokers and the IUGR or AGA infant. Elevated HCG is associated with increased fibrin deposition.

162 HUMAN PLACENTAL GLUCOSE UPTAKE AND TRANSPORT ARE NOT ALTERED BY PHARMACOLOGIC LEVELS OF THE ORAL HYPOGLYCEMIC AGENT. GLYBURIDE. Elliott BD Crosby Schmidt, C ", Langer, 0 Dept. of Ob/Gyn, M4C, Sän Antonio, TX. OBJECTIVE- We have previously demonstrated that minimal transport of glyburide across the human placenta is unaffected by maternal glucose levels or diabetes (AJOG, 1991; SPO, 1993) This study was undertaken to determine whether glyburide increases the placental uptake and transport of glucose to the Cetus STUDY DESIGN: Maternal to fetal transport of H3 glucose was tested in the recirculating single cotyledon placental model in normal term human placentas dually perfused for 3 hours immediately following delivery Glyburide (300 ng/ml) was added to the maternal perfusate in the experimental group and withheld in the control group. Initial maternal glucose concentration was 150 mg/dl, and Ct4 -antipyrine (200 ng/ml) was added to the maternal perfusate in all experiments as an internal control Liquid scintillation spectrometry measured the radiolabeled glucose and antipynne concentrations in the serially collected samples Glucose levels in homogenates of the cotyledons were similarly determined RESULTS: There was no significant difference in the placental transport of glucose between the experimental and control groups by the Mann Whitney U test, nor was there a difference in placental uptake

n 2 Kr % Trampcn GLUCOSE/

ANTIPYRINE PLACENTAL

UPTAKE GLUCOSE ANTIPYRINE RATIO (ng/gm)

G)ybunde 4 149 17.8 . 83 121 Control 4 13.5 146 93 139

CONCLUSIONS: The oral hypoglycemic agent glybunde in pharmacologic doses does not affect the human placental uptake of glucose, nor does it increase glucose transport to the fetus

322 SPO Abstracts

163 NORMAL GLUCOSE UPTAKE AND TRANSPORT OCCUR IN THE DIABETIC PLACENTA. Elliott, B. D., Crosby-Schmit, C, Langer, O. Univ of Texas Health Science Center, San Antonio, TX: OBJECTIVE: There is a paucity of data concerning the effect maternal diabetes and hyperglycemia have on the glucose transport mechanism of the placenta. The purpose of our study is to

characterize glucose transport in the diabetic human placenta. STUDY DESIGN: Transport of Ha-Glucose was tested in the

recirculating single cotyledon human placental model in placentas obtained immediately after delivery from diabetics without vasculopathy and normal controls Each specimen was dually

perfused for 3 hours with Krebs-Ringers buffer at an initial maternal glucose concentration of 150 mg/dl Human albumin (2 gm/dl) was added to the perfusates, and C"-Antipyrine (200 nglml) was added to the maternal perfusate as an internal control. Liquid scintillation spectrometry measured levels of the radiolabeled glucose and antipyrine in the serially collected maternal and fetal samples, and homogenates of the perfused cotyledons RESULTS: No significant difference in mean glucose transport or placental uptake existed between diabetic and normal placentas by Mann-Whitney U test.

Placental Glucose/ Uptake Antipyrine -2 Hr. % Transport-

-(na/am )-Ratio-Glucose-Antiwrine-n-

Diabetic 131 0.94 16.8 180 3

Control 139 0.93 135 14.6 4

CONCLUSION: The diabetic placenta exhibits normal glucose transport and uptake


164 SERUM LYMPHOCYTOTOXIC ANTIBODIES (CYT) IN THE UMBILICAL CIRCULATION OF TWINS WITH GROWTH DISCORDANCE. Michael S. Edwards. Roger B. Newman, Subbi

Mathur, x Dept. Ob/Gyn. Medical University of S. C., Charleston, SC. OBJECTIVE: Fetal CYT against maternal T lymphocytes, especially suppressors (Mathur at al.. 1982; Miyagawa et al., 1982,1983), may play a role in the survival and maintenance of fetal allograft. This

preliminary study aims to test a possible association between titers of these antibodies and the birthweights of normal twins. STUDY DESIGN: Serum CYT titers in the umbilical cord veins of 21

twins with disparate weights were determined by double fluorochromasia cytotoxic antibody assay (Mathur et al., 1982). Paired 't' test and linear regression analysis were done. RESULTS: CYT titers in the heavier twins (group A) were significantly lower (p = 0.01) than those in their lighter cohorts (group B. TABLE). CYT titers between twin cohorts significantly correlated (r a 0.753; p<0.001), as did the birthweights (r - 0.861; p<0.0001). CYT titers and the birthweights did not correlate with each other. TABLE. Birthweights (meant SEM) and CYT (mean 1092, t SEM) of twins (n-21).

Twin A Twin B Paired 't' test P value

Weighla (gm) 2016t 105 1775 t 106 <0.0001 CYTtiters 3.7±0.3 4.5±0.4 0.01

CONCLUSION: It appears from this small study of growth discordant

d twins that the lower birthweight cotwin mounts a greater antibody response than its counterpart. Whether these antibodies affect placentation and therefore fetal growth remains an area of interest.

Poster Session I

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