Early versus late amniotomy during induction of labor using oxytocin: A randomized controlled trial

Abstract

Objective To assess the effect of early amniotomy on labor duration, maternal and neonatal outcomes during induction of labor (IOL). Methods This was a randomized controlled trial, conducted over a period of eight months at a monocentric site. Singleton pregnancies in nulliparous and parous patients with cephalic presentation and Bishop score ≥ 6 were enrolled in the study. One hundred participants were randomized into two groups: early amniotomy (initiating IOL with amniotomy followed by oxytocin) versus late amniotomy (initiating IOL with oxytocin followed by amniotomy 4 hours later). The primary endpoint was the time to active phase (cervical dilation ≥ 5 cm) during IOL. Secondary outcomes were time to vaginal delivery, mode of delivery, and maternal and fetal outcomes. Results Early amniotomy reduced time to active phase by 2 hours and 46 minutes compared to the late amniotomy group (3 h 42 min vs. 6 h 28 min; p<0.0001). It also reduced time to vaginal delivery by 2 hours and 52 minutes (5 h 17 min vs. 8 h 9 min; p = 0.0003). The rate of cesarean section (CS) for failed IOL was significantly lower in the early amniotomy group (31.2% vs. 70.0%; p = 0.02), without any significant difference in the overall rate of cesarean section between the two groups (32.0% vs. 40.8%; p = 0.36). There was no significant difference in maternal or fetal outcomes. Conclusions Early amniotomy in IOL significantly shortens the time to active phase as well as the overall duration of labor without compromising maternal and neonatal safety.