JOURNAL REVIEWS Sharon Bond, CNM, APRN-BC

FETAL OXYGEN SATURATION VIA PULSE OXIMETRY IS NOTASSOCIATED WITH IMPROVED OUTCOMES OR DECREASEDRATES OF CESAREAN DELIVERYBloom SL, Spong CY, Thom E, Varner MW, Rouse DJ, Weininger S,et al. Fetal pulse oximetry and cesarean delivery. N Engl J Med2006;355:2195–202.

Reviewed by: Sharon Bond, CNM, APRN-BC.

Fetal pulse oximetry is a recent adjunctive technology; itis used with electronic fetal monitoring and is intended toenhance the understanding of fetal status in the presenceof non-reassuring fetal heart rate patterns. Its use wasconditionally approved by the U. S. Food and DrugAdministration (FDA) in 2000. A sensor is insertedthrough the dilated cervix and placed against the skin onthe fetal face in laboring women with ruptured mem-branes. A reading then gives a measurement of fetaloxygen saturation. In a previous randomized trial, thisknowledge was shown to influence the management ofwomen with non-reassuring fetal heart rate patterns andsignificantly reduce the incidence of cesarean section. Inthis same trial, however, the rate of cesareans for womenhaving a diagnosis of labor dystocia doubled. Conse-quently, additional studies were undertaken by the FDAto explain these unexpected findings.

This second randomized trial was organized and car-ried out by the National Institute of Child Health andHuman Development Maternal-Fetal Medicine UnitsNetwork in 14 university-based centers between 2002and 2005. Didactic and hands-on training sessions pre-pared all physicians and nurses participating in the trial.After screening and consent, 5341 nulliparous womenhaving non-reassuring fetal heart rate patterns wererandomly assigned to “open” or “masked” fetal pulseoximetry. Though its status was continuously recordedand monitored by research nurses, values in the“masked” group were not known to physicians, and inboth groups labor was managed by physicians accordingto their discretion.

No significant differences were found between the twostudy groups in cesarean section rates, forceps use,vacuum-assisted births, or dystocia. In a subgroup ofwomen noted to have non-reassuring fetal heart ratepatterns before randomization, no differences in rates ofcesarean delivery were found. The sensor was removedfrom women (n � 238 open group, n � 267 in maskedgroup) for reasons including patient or physician requestand technical problems. An unexpected finding was thatnuchal cords were subsequently identified among womenwho had a prolonged deceleration during sensor insertion(n � 54), a rate more than twice what was expected.Trapping of the sensor or inadvertent manipulation of the

fetal head or nuchal cord during insertion was consideredmost likely responsible for these prolonged decelera-tions.

Authors found that low levels of fetal oxygen satura-tion were common among women with both normal andabnormal fetal heart rate patterns and thus the signifi-cance of low oxygen saturation detected on the fetalcheek in labor remains uncertain. At this time, knowl-edge of fetal oxygen saturation appears to have no effecton cesarean rates and shows no benefit when used as anadjunct to fetal heart rate monitoring. The knowledge offetal oxygen saturation does not appear to improve thecondition of newborns. The authors concluded by com-paring fetal pulse oximetry to electronic fetal monitoring.Both represent examples of technology widely applied inpractice before its benefits have been thoroughly re-searched.

PRIMIGRAVIDAS ARE AT INCREASED RISK FOR MENTALHEALTH DISORDERS EARLIER THAN AND BEYOND THE6-WEEK POSTPARTUM CHECK-UP

Munk-Olsen T, Munk Laursen T, Bøcker Pedersen C, Mors O,Mortensen PB. New parents and mental disorders: A population-based register study. JAMA 2006;296:2582–9.Wisner K, Chambers C, Sit D. Postpartum depression: A majorpublic health problem. JAMA 2006;296:2616 – 8.

Reviewed by: Sharon Bond, CNM, APRN-BC.

Postpartum “blues” lasts 1 to 2 weeks and affects 50% ofnew mothers, while postpartum depression (PPD) ismore extreme, affecting 10% to 15% of new mothers,and it may last several weeks, months, or longer. Acombination of hormonal shifts after birth and sleepdeprivation, coupled with the physical and emotionaldemands of caring for a newborn, are a few of thephysiologic and psychosocial factors at work in thedevelopment of PPD. In some women, true depressioncan develop when the “blues” linger or turn increasinglysevere. The objectives of this study were to evaluate therisk of postpartum mental health disorders among newmothers and fathers for 1 year after the birth of their firstchild and to compare these risks with similar individualswho are not parents.

The country of Denmark has a highly centralized andcomputerized record system which allowed researchersto access an extensive database to study 630,373 womenand 547,431 men in the year following the birth of theirfirst child (the study used data collected between 1995–2005). Munk-Olsen et al. designed their study by merg-ing information from two health registries (a civil serviceregistry and a psychiatric central register). They lookedat hospitalizations and outpatient contacts for several

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© 2007 by the American College of Nurse-Midwives 1526-9523/07/$32.00Issued by Elsevier Inc.