Medical treatments for incomplete miscarriage

Miscarriage occurs in 10% to 15% of pregnancies. The traditional treatment, after miscarriage, has been to perform surgery to remove any remaining placental tissues in the uterus ('evacuation of uterus'). However, medical treatments, or expectant care (no treatment), may also be effective, safe, and acceptable.

To assess the effectiveness, safety, and acceptability of any medical treatment for incomplete miscarriage (before 24 weeks).

We searched Cochrane Pregnancy and Childbirth's Trials Register (13 May 2016) and reference lists of retrieved papers.

We included randomised controlled trials comparing medical treatment with expectant care or surgery, or alternative methods of medical treatment. We excluded quasi-randomised trials.

Two review authors independently assessed the studies for inclusion, assessed risk of bias, and carried out data extraction. Data entry was checked. We assessed the quality of the evidence using the GRADE approach.

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.