[Endometriosis and miscarriage: Systematic review]

Objectives: In spontaneous pregnancies, endometriosis appears to be a risk factor of miscarriage. The aim of this study is to evaluate the association between endometriosis and miscarriage in spontaneous pregnancy.

Methods: We searched the Cochrane Library, Medline of eligible studies from inception to December 2016, without any restriction. We selected studies that compared endometriosis-affected pregnant women to disease-free pregnant women. To ensure the quality of the methodology, the PRISMA criteria have been met at all stages of the development of this meta-analysis. The primary adverse pregnancy outcomes studied was miscarriage. Three reviewers independently extracted the studies' characteristics and outcome data.

Results: Of 225 identified abstracts, 4 primary studies met our inclusion criteria by comparing spontaneous pregnant patients with endometriosis to disease-free women. Miscarriage rate was higher in the endometriosis group (OR 1.77 [CI 95% 1.13-2.78]).

Conclusion: In spontaneous pregnancies, endometriosis appears to be a risk factor of miscarriages (almost 80% increased risk). Further prospective studies are needed to confirm these results in order to establish the exact impact of endometriosis on spontaneous pregnancy course.