Primiparous singleton women with endometriosis have an increased risk of preterm birth: Meta-analyses

OBJECTIVE The objective of this study was to assess the association between women with endometriosis and risk of preterm birth. METHODS Two reviewers independently determined all prospective cohort study, retrospective cohort study, large population based cohort study, retrospective secondary analysis, and double blinded, multicentric, observational and cohort study, placebo-controlled, randomized clinical trial published using PubMed, Medline, Korea Education and Research Information Service, and Scopus from March 1994 through February 2016 without language restrictions comparing obstetric outcomes women with endometriosis and women without endometriosis. The meta-analysis was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Six studies met inclusion criteria, including 50,472 women. Among 50,472 pregnancies, 39,659 had endometriosis and 10,813 had no endometriosis. Meta-analyses were estimated with odds ratios and 95% confidence intervals using random effect analysis according to heterogeneity of studies. RESULTS Data from six effect sizes from six studies involving 50,472 patients were enrolled. These meta-analyses showed women with endometriosis have an increased risk of preterm birth (odds ratio, 1.473; 95% confidence interval, 1.216 to 1.785). CONCLUSION These meta-analyses demonstrate women with endometriosis at pregnancy have an increased risk of preterm birth. Therefore, it is worthy for obstetrics to increase the careful inspection in women with endometriosis during pregnancy.