Randomized trial of Dilapan and Laminaria as cervical ripening agents before induction of labor.

A randomized trial was conducted to evaluate the comparative effectiveness of Dilapan cervical dilators and Laminaria japonicum as cervical ripening agents before induction of labor at term. Patients with Bishop scores of 4 or less and a fetal or maternal indication for induction at 34 or more weeks' gestation were eligible for the study. The outcome variables of interest were Bishop score upon removal of the devices, number of devices used, induction-to-delivery time, and induction-to-complete dilatation time. In the Dilapan group, an average of 4.3 devices per patient was used, compared with 9.7 devices in the laminaria group (P less than .01). Among patients who eventually achieved complete dilatation, the mean (+/- SD) time for the Dilapan group was 10.8 +/- 6.1 hours, compared with 14.7 +/- 9.2 hours with laminaria. For women undergoing induction of labor at term with an unripe cervix, Dilapan appeared to be a preferable alternative to Laminaria japonicum because its use may result in a shorter induction-to-delivery interval with fewer devices required to obtain significant cervical ripening.