Mode of delivery in pregnancies with premature rupture of membranes at or before term following induction of labor with vaginal prostaglandin E2

Our aim was to evaluate the mode of delivery in pregnancies complicated with premature rupture of the membranes (PROM) at or before term following induction of labor with vaginal application of prostaglandin E2 (PGE2), and to identify possible predictors leading to cesarean section (CS). The study sample consisted of 220 women with term-PROM who did not enter spontaneous labor after 24 hours of expectant management and 42 with preterm (P)-PROM, who underwent labor induction with vaginal PGE2. Findings were compared with 115 women admitted for elective induction of labor, and 510 women with normal spontaneous-onset labor. There were no between-group differences in gravidity, parity, nulliparity rate, or number of PGE2 tablets used. Women with P-PROM were admitted at 34.6 +/- 2.4 weeks gestation, and delivered at 36.1 +/- 1.6 weeks (mean interval, 5.0 +/- 7.9 days; range, 0.5 to 40 days). The rate of CS was different only between the term-PROM (18.6%) and spontaneous onset of labor (9%) groups (odds ratio, 2.08; 95% confidence interval, 1.4 to 3.4). The rate of low 5-minute Apgar score (< 7) was similar in all groups, but the incidence of nonreassuring fetal heart rate pattern leading to CS was significantly lower in the PROM groups. A logistic regression model and forward likelihood analysis in the PROM groups yielded parity, higher number of PGE2 tablets used, and higher birth weight as independent and significant variables associated with increased risk of CS. Using our management protocol, 36.4% and 20.4% of women with term-PROM and P-PROM, respectively, required labor induction with PGE2, which was successful in more than 80% of cases, with no apparent serious maternal or fetal complications.