Cervical ripening: randomized comparison of intravaginal prostaglandin E2 gel with prostaglandin E2 gel plus laminaria tents

Abstract

The purpose of this study was to evaluate the efficacy of adding laminaria tents to sequential intravaginal prostaglandin E2 (PGE2) gel for cervical ripening. A prospective, randomized study was conducted from October 1994 to May 1995. Pregnant women with maternal or fetal indications for induction of labor at > or = 37 weeks gestation and a Bishop score of < or = 4 were eligible. Nineteen patients received laminaria tents in addition to 4 mg PGE2 gel, while 25 patients received PGE2 gel alone. After 4 hr, the laminaria tents were removed and the gel was continued in both groups at 4-hr intervals. Induction with oxytocin was initiated after a Bishop score of > or = 5 was achieved. The groups were comparable with respect to maternal age, parity, gestational age, reason for induction, and initial Bishop score. The addition of laminaria tents to sequential PGE2 gel did not statistically improve the time to a favorable cervix (control group 12.7 +/- 8.5 hr (95% CI, 9.1-16.3) and study group 10.9 +/- 7.1 hr (95% CI, 7.5-14.3) (P = 0.59). The 6-hr difference from the time of the initial PGE2 gel placement to delivery was not detected (control group 22.4 +/- 11.2 hr, 95% CI 17-27 and study group 23.4 +/- 13.1 hr, 95% CI 17-29.6 (P = 0.79). The combination approach of laminaria tents and PGE2 gel did not have a significant impact on the vaginal delivery rate, with 28.0% of patients in the control group and 26.3% of patients in the study group undergoing cesarean section (P = 0.90). Maternal and neonatal complications were rare in both groups. We had insufficient evidence to show that the addition of laminaria tents to PGE2 gel improved cervical ripening, the induction to delivery interval, or the cesarean section rate in patients at term undergoing induction of labor.