Cervical Ripening

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 ≥37 weeks gestation and a Bishop score of ≤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 >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.