Abstract: We included 24 studies (5577 women). There were no trials specifically of miscarriage treatment after 13 weeks' gestation. Three trials involving 335 women compared misoprostol treatment (all vaginally administered) with expectant care. There was no difference in complete miscarriage (average risk ratio (RR) 1.23, 95% confidence interval (CI) 0.72 to 2.10; 2 studies, 150 women, random-effects; very low-quality evidence), or in the need for surgical evacuation (average RR 0.62, 95% CI 0.17 to 2.26; 2 studies, 308 women, random-effects; low-quality evidence). There were few data on 'deaths or serious complications'. For unplanned surgical intervention, we did not identify any difference between misoprostol and expectant care (average RR 0.62, 95% CI 0.17 to 2.26; 2 studies, 308 women, random-effects; low-quality evidence). Sixteen trials involving 4044 women addressed the comparison of misoprostol (7 studies used oral administration, 6 studies used vaginal, 2 studies sublingual, 1 study combined vaginal + oral) with surgical evacuation. There was a slightly lower incidence of complete miscarriage with misoprostol (average RR 0.96, 95% CI 0.94 to 0.98; 15 studies, 3862 women, random-effects; very low-quality evidence) but with success rate high for both methods. Overall, there were fewer surgical evacuations with misoprostol (average RR 0.05, 95% CI 0.02 to 0.11; 13 studies, 3070 women, random-effects; very low-quality evidence) but more unplanned procedures (average RR 5.03, 95% CI 2.71 to 9.35; 11 studies, 2690 women, random-effects; low-quality evidence). There were few data on 'deaths or serious complications'. Nausea was more common with misoprostol (average RR 2.50, 95% CI 1.53 to 4.09; 11 studies, 3015 women, random-effects; low-quality evidence). We did not identify any difference in women's satisfaction between misoprostol and surgery (average RR 1.00, 95% CI 0.99 to 1.00; 9 studies, 3349 women, random-effects; moderate-quality evidence). More women had vomiting and diarrhoea with misoprostol compared with surgery (vomiting: average RR 1.97, 95% CI 1.36 to 2.85; 10 studies, 2977 women, random-effects; moderate-quality evidence; diarrhoea: average RR 4.82, 95% CI 1.09 to 21.32; 4 studies, 757 women, random-effects; moderate-quality evidence). Five trials compared different routes of administration, or doses, or both, of misoprostol. There was no clear evidence of one regimen being superior to another. Limited evidence suggests that women generally seem satisfied with their care. Long-term follow-up from one included study identified no difference in subsequent fertility between the three approaches. The available evidence suggests that medical treatment, with misoprostol, and expectant care are both acceptable alternatives to routine surgical evacuation given the availability of health service resources to support all three approaches. Further studies, including long-term follow-up, are clearly needed to confirm these findings. There is an urgent need for studies on women who miscarry at more than 13 weeks' gestation.

Plain-language summary: We searched for evidence on 13 May 2016 and identified 24 studies involving 5577 women, and all these studies were of women at less than 13 weeks' gestation. There were a number of different ways of giving the drugs and so there are limited data for each comparison. Overall, the review found no real difference in the success between misoprostol and waiting for spontaneous miscarriage (expectant care), nor between misoprostol and surgery. The overall success rate of treatment (misoprostol and surgery) was over 80% and sometimes as high as 99%, and one study identified no difference in subsequent fertility between methods of medication, surgery or expectant management. Vaginal misoprostol was compared with oral misoprostol in one study which found no difference in success, but there was an increase in the incidence of diarrhoea with oral misoprostol.  However, women on the whole seemed happy with their care, whichever treatment they were given. The review suggests that misoprostol or waiting for spontaneous expulsion of fragments are important alternatives to surgery, but women should be offered an informed choice. Further studies are clearly needed to confirm these findings and should include long-term follow-up. There is an urgent need for studies on women who miscarry at more than 13 weeks' gestation.