OBJECTIVE: A randomized controlled trial was conducted in a university hospital in Malaysia from January 2022 to February 2023. Eligible 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 intervention. 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 interval, -6.4 to -0.7; P=.02). The median
induction of labor (Foley balloon
catheter 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 (interquartile 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
epidural 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 different. 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 neonatal outcomes were not significantly different either.
CONCLUSION: