Single-Balloon Compared With Double-Balloon Catheters for Induction of Labor A Randomized Controlled Trial

OBJECTIVE: To estimate the efficacy of a single-balloon catheter compared with a double-balloon catheter among women with unfavorable cervices undergoing induction of labor. METHODS: 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. RESULTS: 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). CONCLUSION: 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. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials. gov, NCT00690040. (Obstet Gynecol 2011;118:79-86) DOI: 10.1097/AOG.0b013e318220e4b7