Effect of three concentrations of intracervical prostaglandin E2 gel for cervical ripening.

To evaluate the efficacy and safety of three concentrations of prostaglandin E2 (PGE2) gel for preinduction cervical ripening. Two hundred ninety-one patients with an unfavorable cervix scheduled for induction of labor were eligible to participate in a prospective, randomized, double-blind study of one or two doses of intracervical PGE2 gel. Group 1 received a dose of 0.125 mg/2 ml; group 2 received 0.25 mg/2 ml; and group 3 received 0.5 mg/2 ml. Outcome variables included change in Bishop score, uterine tachysystole, oxytocin use, route of delivery, and maternal and neonatal complications. Two hundred twenty-nine patients were included in the study, 79 in group 1, 70 in group 2, and 80 in group 3. Among the three groups, no statistically significant differences were noted for change in Bishop score, uterine tachysystole, oxytocin use, route of delivery, or incidence of maternal or neonatal complications, Subsequent labors were frequently complicated by fetal heart rate abnormalities (24.3%) and uterine tachysystole (9.6%); 84 (38.9%) patients were delivered by cesarean section. A dose-dependent influence on outcome variables was not identified. Complications from PGE2-ripening within 4 hours of gel application were not dose dependent and occurred infrequently. This study demonstrates that there is no dose in the range tested that assures an absences of tachysystole, limiting the role of outpatient cervical ripening without some period of observation.