Mifepristone and misoprostol versus placebo and misoprostol for resolution of miscarriage in women diagnosed with missed miscarriage: the MifeMiso RCT

TRIAL DESIGNA randomised, parallel-group, double-blind, placebo-controlled multicentre study with health economic and nested qualitative studies to determine if mifepristone (Mifegyne®, Exelgyn, Paris, France) plus misoprostol is superior to misoprostol alone for the resolution of missed miscarriage. METHODSWomen diagnosed with missed miscarriage in the first 14 weeks of pregnancy were randomly assigned (1 : 1 ratio) to receive 200 mg of oral mifepristone or matched placebo, followed by 800 μg of misoprostol 2 days later. A web-based randomisation system allocated the women to the two groups, with minimisation for age, body mass index, parity, gestational age, amount of bleeding and randomising centre. The primary outcome was failure to pass the gestational sac within 7 days after randomisation. The prespecified key secondary outcome was requirement for surgery to resolve the miscarriage. A within-trial cost-effectiveness study and a nested qualitative study were also conducted. Women who completed the trial protocol were purposively approached to take part in an interview to explore their satisfaction with and the acceptability of medical management of missed miscarriage. RESULTSA total of 711 women, from 28 hospitals in the UK, were randomised to receive either mifepristone plus misoprostol (357 women) or placebo plus misoprostol (354 women). The follow-up rate for the primary outcome was 98% (696 out of 711 women). The risk of failure to pass the gestational sac within 7 days was 17% (59 out of 348 women) in the mifepristone plus misoprostol group, compared with 24% (82 out of 348 women) in the placebo plus misoprostol group (risk ratio 0.73, 95% confidence interval 0.54 to 0.98; p = 0.04). Surgical intervention to resolve the miscarriage was needed in 17% (62 out of 355 women) in the mifepristone plus misoprostol group, compared with 25% (87 out of 353 women) in the placebo plus misoprostol group (risk ratio 0.70, 95% confidence interval 0.52 to 0.94; p = 0.02). There was no evidence of a difference in the incidence of adverse events between the two groups. A total of 42 women, 19 in the mifepristone plus misoprostol group and 23 in the placebo plus misoprostol group, took part in an interview. Women appeared to have a preference for active management of their miscarriage. Overall, when women experienced care that supported their psychological well-being throughout the care pathway, and information was delivered in a skilled and sensitive manner such t