340

341

Volume 168 Numbe r I , Pa rt 2

THE LIKELIHOOD OF SUCCESSFUL LABOR INDUCTION IN PREECLAMPSIA. N.T. Field.,M. Grant. J.M. Pil1er. A . Samueloff. E. Xenakis. O. Langer.llieUfliv. of Texas HSC at San Antonio. TX. OBJECTIVE : Our objective was to determine whether patients with preeclampsia {PEn have hi~her rates of successful induction than non-preeclamptics {non-PEn induced for other indications. STUDY DESIGN; Of 130 patients with PET. 60 women who underwent induction of labor were identified from an ongoing series of over 2700 consecutive deliveries. 309 non-PET patients being induced for other medical indications (postdates. diabetes. etc.) served as a comparison population . The patients were stratified into the following two groups based on their Bishop score at admission: unfavorable cervix (Bishop 54) and favorable cervix (Bishop > 4). The rates of successful induction and the specific indications for cesarean section. if performed ... were compared between the PET and non-PET cases in both lIishop subgroups. Failed induction was defined as an inability to achieve active Qliase labor corresponding to a cervical dilatation of ~4 em . RESULTS; Gestational age was 38 ± 3 weeks in the PET patients and 39 ± 4 weeks in the non-PET patients. The outcomes of labor induction and indication for cesarean section in both groups with an unfavorable Bishop score (54) are shown below.

PET (n = 38) No PET (n = 234)

Vaginal delivery 60.5%* 81.0% Cesarean Section (overall) 39 .5% * 19.0%

Failed Induction «4 em) 7 .9% * 1.3% Arrest of Dilatation (;,,4 em) 13.2% 6.4% Arrest of Descent 0.0% 2.6% Fetal Distress 10.5% 7 .3%

·p< 0.05 Among women with an unfavorable cervix. preeclamptics had a 6.5x greater likelihood of a failed induction than non-preeclamptics. The relative risk of UndergOing cesarean section for an,>, indication was 2.79 (95% CI. 1.3-5.B for those women with PET as compared to non-PET patients: omparable rates of both cesarean section and failed Induction occurred in both JlroufJS with a favorable Bishop score ( > 4) . CONClUSrON; Our data suggest that women being induced for PET have a much lower likelihOod of successful laDor induction compared with non ·PET patients being induced with equally unfavorable Bishop scores. However. once in active labor. they are at no greater risk of undergoing cesarean section for labor abnormalitres or fetal distress.

DECIDUAL RENIN SECRETION IS MODULATED BY ENDOTHELIAL CELLS M. Grant. D. Shah ., Dept. Ob/Gyn, The University of Texas Health Science Center at San Antonio,TX. OBJECTIVE: Because decidual renin may regulate uterine blood flow and decidual-endothelial cell contacts exist, we examined the modulation of decidual renin secretion by vascular endothelial cells. STUDY DESIGN: Primary human decidual cell cultures were established in 24 well plates on a matrix of human collagen type III, with a density of 2_5 x 105 cells/well. The effect of endothelial cells was studied by decidual-endothelial co-cultures, Human umbilical endothelial cells were plated in half of the wells containing decidual cells and were grown to confluence. Decidual cultures and decidual-endothelial co-cultures were then incubated for 24° in serum-free media. The effect of endothelial cells was also studied by examining cAMP-mediated renin secretion using 10-5 M forskolin. The media were assayed for renin by RIA for angiotensin I (AI) after AI generation. Statistical differences were analyzed by rank order t -test . RESULTS: Basal renin secretion, expressed as mean ± SEM, was 10.4 ± 1.7 ng Allmllhr (N= 11 wells). cAMP increased this to 16.7 ± 1,9 ng Allmllhr (N = 11), p<0.05. Co-culture with vascular endothelium increased renin secretion to 21.2 ± 4.1 ng Allmllhr (N = 10), p < O.Ol. cAMP stimulation in co-cultures increased renin secretion to 27.3 ± 3.4 ng Allmllhr (N = 12), p < O.OOl . CONCLUSION : Decidual renin secretion is increased by cAMP stimulation and in the presence of vascular endothelium . This finding suggests that in vivo decidual-endothelial interaction may modulate decidual renin secretion and thereby regulate uterine blood flow.

SPO Abstracts 391

342 EFFECT OF PREECLAMPTIC SERA AND AMNIOTIC FLUID ON PROSTACYCUN PRODUCTION IN HUMAN ENDOTHEUAL AND MYOMETRIAL CELLS, H,N Wjnn, H. Todd: G. Venezia, x G, Katona" E. Amon, F. Hertelendv. ·

343

Dept. OB/GYN, St. Louis University and St. Mary' s Health Center, St, Louis, MO. OBJECTIVE: Oyslunctioll8l vascular endothelium has been associated with preeclampsia due, perhaps, to circulating lactor(s) that may impair normal endothelial cell functions. This study was designed to compare the effects 01 sera and amniotic fluid (A F) from preeclamptic (PRE), normal pregnant (NP) and non pragnant (NPN) women on PGI, release by umbilical vein endothelial cells (HUVEC) and myometrial cells (HMC) under basal and stimulated conditions. STUDY DESIGN: Monolayer cultures 01 HUVEC and HMC were exposed lor up to 24 hours to various sera and AF specimens obtained Irom 16 patients with documented preeclampsia, or Irom 1 I) normal pregnant subjects, 8$ well 8S sera from nonpregnant volunteers not taking any medication, The release 01 PGI, in the culture medium was determined as 6-keto PGF,. by specific RIA, Statistical evaluation was done by repeated measures ANOVA and Dunnett's t-test . RESULTS: Incubation 01 HUVEC or HMC up to 24 hours with 6-20% PRE sera had no signilicant effect on basal PGI, production compared to NP or NPN sera. However, preincubation of HUVEC with PRE sera lor 20 hours lollowed by 30 minutes Incubation in serum· free media significantly augmented PGI, responses to stimulation with thrombin or the Ca ionophore A23187, Combining PRE sera with AF from either normotensive CJ( PIH women reduced thrombin, but not A23187-promoted PGI, release. CONCLUSIONS: Sera (up to 20%) Irom preeclamptic patients has no apparent advarse effect on PGI, production by HUVEC or HMC under these experimental conditions in vitro.

MID-PREGNANCY SERUM THROMBOXANE B, DETERMI­NATIONS DO NOT PREDICT SUBSEQUENT ADVERSE PREGNANCY OUTCOMES_ D. Rouse: J . HauIh, C. ParI<er: A. Goldenberg. Dept. OB/GYN, UniverSity of Alabama at Birmingham, Birmingham, AL. OBJECTIVE; To determine if mid-pregnancy maternal serum thromboxane B, (TxB,) determinations are predictive of subsequent preeclampsia, pregnancy induced hypertension (PI H) or intrauterine growth retardation (IUGR). STUDY DESIGN: Maternal TxB, was measured from serum samples drawn at the In~iaI recrurtment interview (20-22 weeks) in 542 of 604 women who were randomized to placebo or who failed a pre­randomization compliance test during a trial of low-dose aspirin to prevent preeclampsia. The diagnoses of preeclampsia, PIH and IUGR were assigned at study completion prior to linking the TxB, values to individual participants. We assessed the relationship of TxB, to various adverse outcomes using values above and below both the mean and median, and as depicted below. Significance was defined as P<0.05 using chi-square analyses. RESULTS: Regardless of the TxB, groups used for analysis, we found no significant relationship between the level of TxB, and pregnancy outcome. Two examples of the analyses are shown below.

TxB, preeclampsIa Jl.HlB. .PIli Level (pg/ml)

<5000 7/1 60 (3.9%) >5000 21/362 (5.8%)

TxB, by Quartile (pg/ml) 304-:till

6/160 (4.4%) 26/362 (7 .2"A.)

3,750-UlIII.

8,31e).

iUS

6/160 (4.4%) 21/362 (5.6%)

17,Ole).

.t.Za.3lII!. Preeclampsia (N) 7 5 7 9 IUGR (N) 4 10 10 10 PIH (N) 6 6 11 6

CONCLUSION: Mid-pregnancy maternal serum TxB, does not predict the subsequent development 01 preeclampsia, PIH, or IUGA.