The sequential use of estradiol and prostaglandin E2 topical gels for cervical ripening in high-risk term pregnancies requiring induction of labor.

We compared the safety and efficiency of 200 mg of estradiol valerate prepared as a topical cervical gel as a preripening agent when used 6 hours before the application of 2 mg of prostaglandin E2 gel for the purpose of cervical ripening in 40 high-risk obstetric patients before indicated oxytocin induction of labor. When compared with a placebo prostaglandin E2 dosage, the estradiol had no effect on the change of Bishop score, length of labor, amount of oxytocin required, or the cesarean delivery rate. While no uterine contractions were noted after the application of the estradiol, 85% of patients had recordable uterine activity after the application of prostaglandin E2, suggesting that even at the 2 mg dosage this sequential regimen is not appropriate for local cervical ripening.