Six versus twelve hours of single-balloon catheter placement with oxytocin administration for labor induction: a randomized controlled trial

Induction of labor is common in the United States. Multiple previous studies have tried to outline a faster time to delivery to improve maternal and fetal outcomes.This study aimed to evaluate whether women who undergo induction of labor with a single-balloon catheter and oxytocin have a shorter time to delivery with planned removal of the catheter at 6 vs 12 hours.In this randomized controlled trial, induction of labor was performed using a combination of single-balloon catheter and oxytocin. Term women, both nulliparous and multiparous, aged 18 to 50 years old with cephalic singletons were included if they were undergoing induction of labor with a Bishop score of6 and cervical dilation of2 cm. Women were randomized to planned removal of the single-balloon catheter at 6 hours vs 12 hours. The primary outcome was time from catheter insertion to delivery. We were powered to show a 4-hour time difference with a sample size of 89 women per group (n=178). Planned sensitivity analyses were performed to account for cesarean delivery in labor.From February 2019 to June 2020, 237 women were screened, 178 women were randomized, and 177 women were included in the final analysis (89 women in the 6-hour group and 88 women in the 12-hour group). Insertion to delivery time was significantly shorter in the 6-hour group (19.2 vs 24.3 hours; P=.04), and the proportion of women delivered by 24 hours was significantly greater in the 6-hour group (67.4% vs 47.4%; P.01). There was no difference in the Bishop score at removal of the catheter or secondary maternal or neonatal outcomes. In a Cox proportional-hazards model censoring for cesarean delivery, the 6-hour group had a significantly shorter insertion to delivery time (hazard ratio, 0.67; P=.02).Induction of labor with a single-balloon catheter and oxytocin with planned removal of the catheter at 6 hours rather than 12 hours results in a shorter time from insertion to delivery without increasing the rate of cesarean delivery. Decreasing the length of time a single-balloon catheter is in place should be considered in clinical protocols.