407: Association between timing of rupture of membranes and length of labor induction: Secondary analysis of a randomized controlled trial

Abstract

Evaluate the impact of timing of rupture of membranes (ROM) on length of labor on women admitted for induction of labor. This study was a secondary analysis of a randomized, multicenter, trial of women with a singleton pregnancy at 24 weeks of gestation or greater undergoing labor induction with cervical ripening, who were randomized to intracervical Foley catheter with or without concurrent oxytocin. Women with premature rupture of membranes (PROM) or preterm PROM were excluded. Patients were analyzed in two cohorts based on timing of ROM in relation to catheter expulsion: within 4 hours versus greater than 4 hour from expulsion. Primary outcome was length of induction (from first agent to delivery), and secondary outcomes included rates of delivery within 12 and 24 hours, cesarean delivery rate, estimated blood loss (EBL), clinical chorioamnionitis, endometritis, umbilical cord prolapse, neonatal ICU admission, and culture-proven neonatal sepsis. In women undergoing labor induction, early ROM was associated with a significant decrease in length of induction (16.3 vs 23.8, p= 0.003). Early ROM was also associated with significantly more women delivering within 12 (33 vs 10 percent, p=0.005) and 24 hours (91 vs 59 percent, p=0.009), compared to late ROM. Cesarean delivery rates did not differ between early and late ROM groups. Maternal and neonatal complications were not significantly different between the groups. There were no cases of cord prolapse or neonatal sepsis in either group. In women undergoing labor induction requiring cervical ripening, early membrane rupture is associated with significant decrease in length of labor, without increasing maternal or neonatal adverse outcomes.