Induction of labor with vaginal prostaglandin E2

Abstract

Objective: To determine the effects of labor induction with vaginal prostaglandin E 2 (PGE2) on mode of delivery in post-term pregnancies and to identify possible predictors of successful vaginal delivery. Methods: The study group consisted of 211 women with post-term pregnancy (gestational age more than a full 41 weeks) admitted for induction of labor with vaginal applications of PGE 2. Findings were compared with women with spontaneous onset of labor (group 2, n = 510). Women with previous Cesarean section were excluded from both study and control groups. Results: The rate of Cesarean section was significantly higher in the study group (19.4%) than in the control group (9%). A logistic regression model was used to control for maternal and gestational age, gravidity, parity, nulliparity rate, number of used PGE 2 tablets, oligohydramnios and delivery weight as possible predictors of Cesarean section ( R 2 = 0.56, p < 0.001). On stepwise analysis, nulliparity (OR 45.2, 95% CI 2.93‐ 695.5), number of PGE 2 applications (OR 2.79, 95% CI 1.04‐ 7.52) and maternal age (OR 1.23, 95% CI 1.01‐ 1.50) were independently and significantly associated with increased risk of Cesarean section. PGE 2 induction was a significant independent predictor of Cesarean section (OR 2.3, 95% CI 1.3‐ 3.9). Conclusion: PGE2 induction of labor was successful in approximately 80% of patients with postterm pregnancy, with apparently no serious maternal or fetal complications. Risk factors intrinsic to the patient, and labor induction itself, were the reasons for excess Cesarean deliveries in women with prolonged pregnancies.