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

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 16 h 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 induction-delivery intervals (7.9 h vs 12.0 h, P < 0.001; and 5.7 vs 10.4 h, 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 20 h. 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.