Randomized trial of preinduction cervical ripening: misoprostol vs oxytocin.

Objective: The purpose of this study was to compare the vaginal delivery rate in women who undergo labor induction with preinduction misoprostol or oxytocin alone.

Study Design: Women with singleton pregnancies and Bishop scores <5 with labor induction at > or = 24 weeks of gestation were eligible; they were assigned randomly to oxytocin alone or preinduction cervical ripening with misoprostol. Labor characteristics, maternal complications, and neonatal outcomes were analyzed.

Results: One hundred sixty-three women received oxytocin, and 164 women received misoprostol. Maternal demographics, pretreatment Bishop scores, and labor analgesia were similar between groups. Vaginal delivery rates were also similar: 87% (n = 141) for oxytocin and 81% (n = 133) for misoprostol. Mean time from treatment to delivery was shorter for the oxytocin group, compared with the misoprostol group (13.1 vs 16.3 hours; P = .005). There was no difference in maternal complications or neonatal outcomes between groups.

Conclusion: Preinduction cervical ripening with misoprostol did not improve the vaginal delivery rate and resulted in longer intervals to active labor and delivery. Preinduction cervical ripening with misoprostol may not be necessary.