Use of mifepristone to ripen the cervix and induce labor in term pregnancies

Objective This study was undertaken to determine the efficacy of mifepristone for ripening the cervix and inducing labor in term pregnancies. Study design In a double-blind placebo-controlled dose-finding study, 346 women received 50, 100, 200, 400, or 600 mg of mifepristone or placebo. The main endpoint for efficacy was the number of patients in whom labor occurred between 12 and 45 and 54 hours after treatment or who had a Bishop score 6 or greater. Maternal and fetal tolerability was also studied. Results No significant efficacy was observed whatever the dose of mifepristone. Mifepristone was well tolerated by the mother and fetus. Conclusion Mifepristone, at doses up to 600 mg, does not induce labor within 54 hours in patients with unfavourable cervical status.