Induction of labor via Foley balloon catheter placement for 6 vs 12 hours in women with 1 previous cesarean delivery and unfavorable cervices: a randomized controlled trial

BACKGROUND: Induction of labor in women with 1 previous cesarean delivery and unripe cervices is a high-risk process, carrying an increased risk of uterine rupture and the need for cesarean delivery. Balloon ripening is often chosen as prostaglandin use is associated with an appreciable risk of uterine rupture in vaginal birth after cesarean delivery. A shorter duration of placement of the balloon typically expedites delivery; however, this has not been evaluated in induction of labor after 1 previous cesarean delivery. OBJECTIVE: This study aimed to compare Foley balloon catheter placement for 6 vs 12 hours in induction of labor after 1 previous cesar-ean delivery.STUDY DESIGN: A randomized controlled trial was conducted in a university hospital in Malaysia from January 2022 to February 2023. Eligi-ble women with 1 previous cesarean delivery admitted for induction of labor were enrolled. Participants were randomized after balloon catheter insertion for 6 or 12 hours of passive ripening before balloon deflation and removal to check cervical status for amniotomy. The primary outcome was the induction of labor to delivery interval. The secondary outcomes were largely derived from the core outcome set for trials on induction of labor (Core Outcomes in Women's and Newborn Health [CROWN]). The Student t test, Mann-Whitney U test, chi-square test, and Fisher exact test were used as appropriate for the data.RESULTS: Overall, 126 women were randomized, 63 to each interven-tion. The mean induction of labor to delivery intervals were 23.0 (standard deviation, +/- 8.9) in the 6-hour arm and 26.6 (standard deviation, +/- 7.1) in the 12-hour arm (mean difference,-3.5 hours; 95% confidence inter -val,-6.4 to-0.7; P=.02). The median induction of labor (Foley ballooncatheter insertion) to Foley balloon catheter removal intervals were 6.0 hours (interquartile range, 6.0-6.3) in the 6-hour arm and 12.0 hours (interquartile range, 12.0-12.5) in the 12-hour arm (P<.001). The median induction of labor to amniotomy intervals were 14.1 hours (inter -quartile range, 9.3-21.8) in the 6-hour arm and 19.0 hours (interquartile range, 15.9-22.0) in the 12-hour arm (P=.02). The usage rates of epidu-ral analgesia in labor were 46.0% (29/63) in the 6-hour arm and 65.1% (41/63) in the 12-hour arm (relative risk, 0.71; 95% confidence interval, 0.51-0.98; P=.03). Spontaneous balloon catheter expulsion rates were 22.2% (14/63) in the 6-hour arm and 17.5% (11/63) in the 12-hour arm (relative risk, 1.27; 95% confidence interval, 0.63-2.58; P=.50), and additional ripening use rates (Foley reinsertion) were 46.0% (29/63) in the 6-hour arm and 31.7% (20/63) in the 12-hour arm (relative risk, 1.45; 95% confidence interval, 0.92-2.27; P=.10). The results were not differ-ent. Moreover, maternal satisfaction scores (0-10 numerical rating scale) of 9 (range, 8-10) in the 6-hour arm and 9 (range, 8-10) in the 12-hour arm (P=.41) were not different. Other secondary maternal and neo-natal outcomes were not significantly different either.CONCLUSION: Foley balloon catheter placement for 6 hours hastened birth and reduced epidural analgesia use in labor without a change in maternal satisfaction.