Sustained-Release Dinoprostone Vaginal Pessary with Concurrent High-Dose Oxytocin Infusion Compared to Sustained-Release Dinoprostone Vaginal Pessary Followed 6 h Later by High-Dose Oxytocin Infusion for Labor Induction in Women at Term with Unfavorable Cervix: A Randomized Controlled Trial

Abstract

Objective: To compare the efficacy and safety of sustained-release dinoprostone vaginal pessary and concurrent high-dose oxytocin infusion with sustained-release dinoprostone vaginal pessary followed 6 h later by high-dose oxytocin infusion for cervical ripening and labor induction. Methods: A total of 500 nulliparous or multiparous women with a singleton pregnancy, Bishop score ≤4 and admitted for labor induction. Women were randomly assigned to induction of labor using intravaginal dinoprostone with concurrent high-dose oxytocin (n = 250) or intravaginal dinoprostone pessary followed 6 h later by high-dose oxytocin (n = 250). The primary outcome was the number of vaginal deliveries achieved within 24 h of labor induction. Results: Baseline characteristics of both groups were comparable. Vaginal delivery within 24 h of labor induction was significantly increased with sustained-release dinoprostone followed 6 h later by high-dose oxytocin infusion (92.8 vs. 82.0%, RR 2.82, 95% CI 1.58–5.04). There were more cesarean section deliveries in the dinoprostone with concurrent high-dose oxytocin group (16.8 vs. 6.8%, RR 0.36, 95% CI 0.20–0.65). Maternal outcomes did not differ significantly. An Apgar score of <7 at 5 min was found more often in the dinoprostone with concurrent high-dose oxytocin group (3.6%) in comparison to dinoprostone pessary followed 6 h later by high-dose oxytocin (0.8%), although this was not statistically different (RR 0.21, 95% CI 0.04–1.01). Conclusion: Sustained-release dinoprostone followed 6 h later by high-dose oxytocin infusion appears to be safer and more effective than sustained-release dinoprostone with concurrent high-dose oxytocin infusion in achieving cervical ripening and successful vaginal delivery.