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.