The Effect of Endometriosis on In Vitro Fertilization Outcomes: A Systematic Review and Meta-Analysis

The purpose of this study was to evaluate the impact of endometriosis on various outcomes of in vitro fertilization (IVF), including live birth rates, clinical pregnancy rates, fertilization rates, and implantation rates, through a systematic review and meta-analysis. Methods: Systematic searches were carried out using PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Scopus, EMBASE, and Web of Science from January 2010 to November 2023. Studies comparing IVF outcomes in women with and without endometriosis were included. The primary outcome was live birth rate; secondary outcomes included clinical pregnancy, fertilization, and implantation rates. Data were extracted and analyzed using odds ratio (OR) and 95% confidence interval (CI) with fixed or random-effects models, depending on heterogeneity. Results: From 1340 studies initially identified, 40 studies met the inclusion criteria, encompassing 8970 women with endometriosis and 42,946 control participants. There were no significant differences between the endometriosis and control groups in terms of live birth rate (OR 1.03, 95% CI 0.75–1.41, p = 0.84), clinical pregnancy rate (OR 0.86, 95% CI 0.72–1.02, p = 0.1), or fertilization rate (OR 0.96, 95% CI 0.79–1.15, p = 0.64). However, endometriosis was associated with a significantly lower implantation rate (OR 0.85, 95% CI 0.74–0.97, p = 0.02). Conclusions: Endometriosis significantly negatively affects implantation rates in women undergoing IVF, despite the absence of significant differences in live birth, clinical pregnancy, and fertilization rates. Further research is needed to evaluate the impact of different stages of endometriosis on IVF outcomes and to develop optimized management protocols for these patients.