Efficacy and safety of controlled‐release dinoprostone vaginal delivery system ( PROPESS ) in Japanese pregnant women requiring cervical ripening: Results from a multicenter, randomized, double‐blind, placebo‐controlled phase III study

AIM: To evaluate the efficacy and safety of dinoprostone vaginal insert (PROPESS) in pregnant post-term Japanese women requiring cervical ripening. METHODS: This randomized, double-blind, placebo-controlled study included 114 pregnant Japanese women at term (41 weeks of gestation) requiring cervical ripening (baseline Bishop score (BS) ≤ 4). The primary end-point was the proportion of subjects with successful cervical ripening defined as BS ≥ 7 or vaginal delivery in 12 h. The secondary end-points were changes in BS, proportion of women with vaginal delivery, proportion of women receiving mechanical cervical ripening procedure and use of oxytocic drugs. RESULTS: PROPESS administration for a maximum of 12 h showed significantly higher successful cervical ripening rate (47.4% vs 14.3%, respectively; treatment contrast [TC]: 33.1%; P = 0.0002). The median time from administration to vaginal delivery was significantly shorter in the PROPESS group than in the placebo group (26.18 h vs 33.02 h; OR 2.51; 95% CI [1.60-3.92]; P < 0.0001). In the PROPESS group, the dosage of uterotonic drugs, such as oxytocin, decreased, and the number of patients who used these drugs also decreased. CONCLUSION: PROPESS administration for a maximum of 12 h was an effective and well-tolerated treatment for pregnant Japanese women post-term requiring cervical ripening.