Perinatal Outcomes in Cephalic Compared with Noncephalic Singleton Presentation in the Setting of Preterm Premature Rupture of Membranes before 32 Weeks of Gestation

OBJECTIVE: To investigate the relationship between fetal presentation at the time of admission for preterm premature rupture of membranes (PROM) and perinatal outcomes, including gestational latency, among women in a large and well-characterized population with preterm PROM at less than 32 weeks of gestation. METHODS: This was a secondary analysis of data from women randomized to receive magnesium sulfate compared with placebo in the previously reported Maternal-Fetal Medicine Units Network Beneficial Effects of Antenatal Magnesium Sulfate (1997-2004) trial. Women with a singleton gestation and preterm PROM were included. Fetal presentation at the time of randomization was recorded. Associations of fetal position (cephalic compared with noncephalic) with perinatal outcomes were compared using χ 2, Fisher exact, and Wilcoxon rank-sum tests. Perinatal outcomes included gestational latency, abruption, and neonatal morbidity and mortality. Multivariable regression (logistic, linear, and Cox) analyses were used to adjust for potential confounding factors. RESULTS: Of the 1,767 eligible women, 439 (24.5%) had a noncephalic presentation. Noncephalic presentation was associated with an earlier median gestational age at the time of preterm PROM (26.6 compared with 28.4 weeks of gestation, P<.001), but no difference in gestational latency (7.5 compared with 7.7 days, P.7, adjusted hazard ratio 1.09, 95% confidence interval [CI] 0.97-1.23). There were no differences in odds of abruption or neonatal morbidity in multivariable analyses. However, even after controlling for potential confounding factors including gestational age at delivery and mode of delivery, odds of neonatal death before discharge was greater for noncephalic gestations (11.5% compared with 3.4%, P<.001; adjusted odds ratio 2.24, 95% CI 1.12-4.48). CONCLUSION: Even after controlling for gestational age and route of delivery, noncephalic fetuses in the setting of preterm PROM are at greater risk of neonatal death.