Mifepristone and Misoprostol Versus Misoprostol Alone in the Medical Management of Missed Miscarriage

Miscarriage is the most common complication of pregnancy. As many as 15-25% of pregnancies end in miscarriage, and the number of miscarriages in England is estimated to be approximately 125,000 per year. Miscarriage often brings not only physical pain, bleeding and risks of infection, but also psychological impacts on women and their families. This study will focus on women whose pregnancy sac remains inside the womb (known as a missed miscarriage) and opt for medical management of their miscarriage up to 13+6 weeks of pregnancy. NICE currently recommends that a drug called misoprostol (a vaginal pessary or oral tablet that makes the womb contract) should be used in the medical treatment of miscarriage. However, there is evidence to suggest that combining this drug with mifepristone (an oral tablet that reduces pregnancy hormones) may be more effective in treating miscarriage. Therefore, to test this in a clinical trial, participants will be allocated at random to receive either mifepristone followed by misoprostol, or a dummy drug (placebo) followed by misoprostol. Neither the participants nor the researchers will know what allocation is decided, which is necessary to test the treatments fairly. The main outcome of interest will be whether miscarriage is complete within 7 days of randomisation. If miscarriage is not complete then further treatment (more tablets or surgery) will be offered. A number of other key outcomes, such as the need for an operation, will also be assessed. We will also study the views and experience of the participants regarding the tablet treatment. We anticipate that 710 women will be required to take part in the study to answer this question with confidence. We estimate that we would be able to recruit this many women in two years.