Tugging the Foley Catheter Balloon Every Three Hours in Induction of Labor After One Previous Cesarean: A Randomized Controlled Trial.

Background: Induction of labor after one previous cesarean (IOLAC) with unripe cervixes is at especially high risk for unplanned cesarean birth and uterine rupture. Balloon mechanical ripening is often preferred over prostaglandin during IOLAC, as uterine rupture is associated with prostaglandin use. The transcervical Foley balloon can dislodged past the ripened cervix and be comfortably retained in the vagina during passive placement. Tugging of the Foley catheter can be a non-invasive and tolerated method for timelier retrieval of the retained balloon; expediting discovery of a ripened cervix, permitting follow-on amniotomy and oxytocin infusion, thus hastening birth.

Objective: To evaluate tugging the Foley balloon for 30 seconds every three hours compared to standard care (no tugging) during the 12 hours of scheduled placement on the induction to birth interval and patient satisfaction.

Method: A randomized controlled trial in a university hospital in Malaysia recruited participants from April 2023 to March 2024. Eligible participants admitted for Foley balloon induction of labor who had one previous cesarean were recruited. After balloon insertion, participants were randomized to tugging or standard care. Following balloon displacement, a vaginal examination was performed to check the cervix. The examination findings then dictated follow-on IOLAC management according to usual practice. The primary outcomes were the induction (Foley insertion) to delivery interval and participants' satisfaction with the birth process. Secondary outcomes were largely derived from the core outcome set for trials (CROWN) on IOL. A sample size of 126 was calculated to cover for a 4 hours reduction in the induction to delivery interval and a 1.5 point increase in satisfaction score based on 0-10 numerical rating scale predicated on a superiority hypothesis with the level of significance set at 0.05, power at 80% and a 10% drop out rate. Analysis was by t-test, Mann-Whitney U test, Chi square test and Fisher exact test as appropriate to the data on an intention-to-treat basis.

Results: 126 participants were randomized; 63 to each trial arm. The induction to birth interval was (mean±standard deviation) 29.7±9.6 hours vs. 29.8±9.1 hours p=0.950 and maternal satisfaction with the IOLAC birth process assessed by 0-10 numerical rating scale was median [interquartile range] 8[7-9] vs. 8[7-9] p=0.936 for 3-hourly tugging and standard care respectively. Caesarean delivery rate was 37/63 (59%) vs. 41/63 (65%) p=0.238 and the main indication for unplanned caesarean was failure to progress was 24/37 (65%) vs. 24/41 (59%) p=0.914 in tugging vs. standard care arms respectively. Three-hourly tugging also did not shorten the intervals from induction to balloon displacement, amniotomy, start of oxytocin infusion or the second stage.

Conclusion: At Foley balloon IOLAC with a scheduled 12 hour balloon placement, tugging the catheter every three hours compared to standard care did not hasten birth or improve patient satisfaction.