[Endometriosis and miscarriage: Systematic review]

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.

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.

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]).

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.