Randomized controlled trial of vaginal misoprostol versus dinoprostone vaginal insert for labor induction

Objective: To compare the safety and efficacy of vaginal misoprostol versus dinoprostone vaginal inserts for cervical ripening and labor induction. Methods: Two hundred singleton gestations with an indication for cervical ripening and induction of labor were randomized to receive either 50 μg of misoprostol intravaginally every 3 h or a 10-mg dinoprostone vaginal insert every 12 h for a maximum of 24 h. Statistical analysis included Student's t test, the Mann-Whitney U test, χ² analysis and Fisher's exact test. Results: Ninety-seven women received vaginal misoprostol while 89 women received the dinoprostone vaginal insert. Fourteen women were removed from the study after randomization. The interval from start of induction to vaginal delivery (794.5 ± 408 min vs. 1005.3 ± 523 min; p < 0.02) was significantly shorter in the misoprostol group. Women receiving misoprostol were more likely to deliver vaginally both in < 12 h (44% vs. 12%; p < 0.0001) and < 24 h (68% vs. 38%; p < 0.001). A non-reassuring fetal heart rate tracing was the indication for 71.4% (20/28) of Cesarean deliveries in the misoprostol group compared to 40% (14/35) in the dinoprostone group (p = 0.03). There were no significant differences in neonatal outcomes. Conclusion: Intravaginal misoprostol and dinoprostone are safe and effective medications for use in cervical ripening before labor induction. Misoprostol results in a shorter interval from induction to delivery. However, Cesarean delivery for a non-reassuring fetal heart rate tracing was more common with misoprostol.