Combination of misoprostol and mechanical dilation for induction of labour: a randomized controlled trial

Abstract

Objective: To evaluate a combination of oral misoprostol (OM) and mechanical dilation of the cervix to improve efficacy in inducing labour.

Study design: This prospective, randomized study included 122 term pregnancies with an indication for induced labour. Each woman was randomly assigned to one of two groups. In the study group, a combination of OM and mechanical dilation with a double-balloon catheter for cervical ripening was used. In the control group, only OM was administered. The primary outcome measure was the rate of failure to induce labour, defined as no vaginal delivery within 48h.

Results: In the study group, the rate of failure to induce labour was significantly lower in comparison with the control group (9.3% vs. 21.2%; P=0.007). The median times for inducing labour were 15.3h in the study group and 20.8h in the control group (P=0.158). There were no significant differences between the two groups with regard to other outcome parameters. As there were no failures of induced labour among women with premature rupture of membranes, the study results were also evaluated after excluding these cases. Among those women without rupture of membranes, the median times for induction were 15.8h in the study group and 32.6h in the control group (P=0.024). The rates of failure to induce labour were 10.8% vs. 28.2% (P=0.002).

Conclusion: A combination of OM and a double-balloon catheter improves the efficacy of labour induction in term pregnancies, particularly in women without premature rupture of the membranes.