Oxytocin versus sustained-release dinoprostone vaginal pessary for labor induction of unfavorable cervix with Bishop score >= 4 and >= 6: A randomized controlled trial

Abstract

Aim To compare the efficacy and safety of high-dose intravenous oxytocin and sustained-release dinoprostone vaginal pessaries for cervical ripening and labor induction in pregnant patients at term with poor Bishop scores. Material and Methods Women at term with a Bishop score 4 and 6 were randomized into two groups to undergo induction of labor with either high-dose oxytocin administered intravenously (n=90) or dinoprostone-only vaginal pessary without oxytocin augmentation (n=90). The main outcome measures were rate of cesarean delivery, induction to delivery interval, number of deliveries achieved within 4, 8, 12, and 16h of labor induction, maternal complications during induction, fetal outcome, and total hospital stay. In this study, per-protocol analysis was performed. Results There were fewer cesarean deliveries with oxytocin compared to dinoprostone-only groups (7/79 vs 14/89); however, the difference was not statistically significant. The inductiondelivery intervals (7.9h vs 12.0h, P<0.001; and 5.7 vs 10.4h, P<0.001; oxytocin vs dinoprostone-only for primiparous and multiparous patients, respectively) were significantly shorter in oxytocin-induced patients compared to dinoprostone-only. A significantly higher percentage of patients delivered in the oxytocin group compared to the dinoprostone-only group in 4, 8, 12, 16, and 20h. Conclusion Intravenous oxytocin is effective to stimulate labor at term for patients with Bishop scores 4 and 6, with a shorter time interval from induction to vaginal delivery.