Single-balloon compared with double-balloon catheters for induction of labor: a randomized controlled trial

To estimate the efficacy of a single-balloon catheter compared with a double-balloon catheter among women with unfavorable cervices undergoing induction of labor.

This prospective randomized study was conducted at a university teaching medical center between June 2008 and December 2010. Pregnant women admitted for induction of labor with a live singleton gestation in cephalic presentation with intact membranes and a Bishop score of 6 or less were randomly assigned for cervical ripening by a single-balloon catheter or a double-balloon catheter. The primary outcome was the length of time from catheter insertion until delivery. The secondary outcome was mode of delivery.

Of 368 eligible women screened during the study period, 293 were included in the final analysis; 145 were randomly assigned to receive a single-balloon catheter and 148 received a double-balloon catheter. Demographic and obstetric parameters were comparable between the two groups. Length of time from catheter insertion until delivery was 19.4 (±6.0) and 19.1 (±6.8) hours among the single-balloon and the double-balloon catheter groups, respectively (P=.80). Length of time did not differ when primiparous women were analyzed separately. Incidence of cesarean delivery was 10.3% and 17.6% among the single-balloon and double-balloon catheter groups, respectively (P=.09). The incidence of either vacuum deliveries or cesarean deliveries was significantly lower among the single-balloon group (14.4%) compared with the double-balloon catheter group (25.7%; odds ratio 0.49, 95% confidence interval 0.26-0.92; P=.02).

Both the single-balloon and double-balloon catheters are equally efficacious for inducing labor. The double-balloon catheter may be associated with more operative deliveries.