The frequency of endometriosis in the general and selected populations: A systematic review

Background: In this article, we have reviewed available data on the frequency of endometriosis considering separately the incidence and the prevalence of the disease using data from papers published from 2000 to June 2019. Study design: Systematic review and meta-analysis. PubMed and EMBASE were searched for observational studies reporting data on the incidence or prevalence rates or ratios for the following pre-specified populations: general population, infertile women, women reporting pelvic pain, women who underwent pelvic surgical procedures unrelated with endometriosis. Results: A total of 42 papers were included in this review. Considering the 11 studies that have analysed the prevalence of endometriosis in the general population, the reported prevalence ranged from 0.8% to 28.6% with an overall estimated of 4.4% (95% CI 3.6–5.2). When we considered separately the estimates reported in each study according to geographic area, the pooled estimate was lower in the European studies (1.4%), increased to 5.7% in the US studies and was 15.4% in the Asian ones. The pooled estimated prevalence of endometriosis was 33.5% (95% CI 24.3–42.8, Figure 2(c)) in women who underwent surgery for benign gynaecological conditions, 23.8% (95% CI 16.1–31.5, Figure 2(d)) in infertile women, and 49.7 % (95% CI 14.4–85.0) in women with chronic pelvic pain. Conclusion: This review offers an overview of the available data on the frequency of endometriosis in the general population and in selected population, in particular among infertile women and women with chronic pelvic pain.