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.