Comparison of intravenous oxytocin and vaginal prostaglandin E2 gel in women with unripe cervixes and premature rupture of the membranes.

To induce cervical priming and labor, 20 nulliparous term pregnant women with premature rupture of the membranes and unfavorable cervical states were randomly given either oxytocin intravenously or 4 mg prostaglandin E2 in gel intravaginally. One of ten women receiving oxytocin had a favorable cervical state within five hours and vaginal delivery within 24 hours after the start of the infusion compared with six of ten women after prostaglandin E2 gel application. This difference is statistically significant (P less than .01). The number of instrumental deliveries was nine (four cesarean sections and five vacuum extractions) in the oxytocin-treated patients compared with only two vacuum extractions in women who received prostaglandin E2 gel. This difference is also statistically significant (P less than .01, Fischer exact test). In a subsequent open study, 4 mg prostaglandin E2 gel was applied vaginally to 17 term pregnant women of mixed parity with premature rupture of the membranes and unfavorable cervixes. In 12 women a favorable cervical state was achieved within five hours after gel application, and all these women were delivered within 24 hours. None of the women required cesarean section but two required delivery by vacuum extraction. There were no perinatal losses, but two infants in the oxytocin-treated group had Apgar scores less than 7 at five minutes. At pediatric follow-up after two and six months, all infants were normal. In both obstetric and perinatal outcome prostaglandin E2 gel thus seems to be superior to oxytocin for labor induction in term pregnant patients with premature rupture of the membranes and unfavorable cervixes.