A Cochrane review included 10 trials with a total of 1 108 women. Mifepristone treated women were more likely to be in labour or to have a favourable cervix within 48 and 96 hours of treatment than were placebo treated/no treatment women (48 hours: RR 2.41, 95% CI 1.70 to 3.42, 4 studies, n= 293; 96 hours: RR 3.40, 95% CI 1.96 to 5.92, 2 studies, n=144). They were less likely to need augmentation with oxytocin (RR 0.80, 95% CI 0.66 to 0.97; 5 studies, n=499). Mifepristone treated women were less likely to undergo caesarean section (RR 0.74, 95% CI 0.60 to 0.92; 9 studies, n=1 043), but more likely to have an instrumental delivery (RR 1.43, 95% CI 1.04 to 1.96; 7 studies, n=814). Women receiving mifepristone were less likely to undergo a caesarean section as a result of failure to induce labour (RR 0.40, 95% CI 0.20 to 0.80). Abnormal fetal heart rate patterns were more common after mifepristone treatment (RR 1.85, 95% CI 1.17 to 2.93), but there was no evidence of differences in other neonatal outcomes. There is insufficient information on the occurrence of uterine rupture/dehiscence in the reviewed studies.
Comment: The quality of evidence is downgraded by imprecise results (few patients and wide confidence intervals).