44 Six vs. Twelve Hours of Foley Catheter Placement for Induction: A Randomized Controlled Trial

Abstract

To evaluate whether time to delivery is shorter for women who undergo an induction with cook catheter and oxytocin for six as compared to twelve hours In this randomized controlled trial, labor induction was performed using combination cook catheter and oxytocin. Term women aged 18-50 years old with vertex singletons were included if they were undergoing induction of labor with a Bishop score less than 6 and dilation less than 2cm. Women were randomized to planned removal of the cook catheter at six or twelve hours. Primary outcome was insertion-to-delivery time. We were powered to detect a 4-hour difference with a sample size of 89 women per group (n=178). Planned sensitivity analyses were performed (a) excluding cesarean deliveries and (b) using Cox Proportional Hazards models censoring for cesarean delivery in labor. From February 2019-June 2020 237 women were screened and 178 were randomized 1:1. One person in the twelve-hour group was excluded because her induction was interrupted. Women were similar with regards to baseline characteristics including parity (71% nulliparous in six-hour group and 68% in the twelve-hour group; p=). Insertion-to-delivery time was significantly shorter in the six-hour group (19.2 vs. 24.3 hours, p=0.04) and the proportion of women delivered by 24 hours was significantly greater in the six-hour group (67% vs. 47%, p<0.01). There was no difference in Bishop score at removal. In the Cox Proportional Hazard Model, the six-hour group had a significantly shorter time to delivery (HR 0.67, p=0.02). (Figure 1). There were no differences in cesarean delivery rates (19% vs. 28%, p=0.15) nor any differences in other maternal or neonatal outcomes, including infection rates. Labor induction with a cook catheter and oxytocin with planned removal at 6 hours, rather than 12 hours, results in shorter time to delivery. Decreasing the planned length of time a cook catheter is in place should be considered in clinical protocols.