Serial intravaginal prostaglandin E2 gel cervical ripening in preterm pregnancies

Objective: To determine if prostaglandin (PG) E₂ cervical ripening is safe and effective in high-risk preterm pregnant women who do not have an indication for immediate delivery.

Methods: This was a retrospective case-control study of preterm pregnant women treated with sequential PGE2 gel between 3/1/92 and 3/1/95. Study subjects were between 24 and 36 weeks gestation, had intact membranes, and complications requiring inpatient monitoring but not immediate delivery. PGE₂ gel was inserted serially until either maternal or fetal deterioration required intervention, fetal maturity was achieved, a Bishop ≥ 7 was reached, or the patient improved and was discharged. Control subjects were matched for inclusion criteria and diagnoses on admission.

Results: A total of 22 study and 22 control patients were evaluated. The gestational age at admission was 32.3 ± 2.8 versus 31.8 ± 2.9 weeks. The mean number of PGE₂ gel applications was 11.6 over a mean of 5.0 days. Intervention during ripening was required in 11 (50%). A Bishop score ≥ 7 without labor was achieved in 11 (50%), and labor during the ripening process occurred in 2 (9%). The mean time from Bishop ≥ 7 to delivery was 2.6 days. The total cesarean delivery rate was 10 (45%) versus 15 (68%), in the control group (P = NS). Neonatal outcomes were similar.

Conclusions: Sequential PGE₂ gel cervical ripening when used in preterm pregnant women improves the Bishop score, and has a low incidence of spontaneous preterm labor.