The Impact of Endometriosis on Embryo Quality in in-vitro Fertilization/Intracytoplasmic Sperm Injection: A Systematic Review and Meta-Analysis

Background: The association between endometriosis and embryological outcomes remains uncertain. The meta-analysis aimed to evaluate the impact of endometriosis on embryo quality. Methods: A systematic review and meta-analysis was conducted to investigate the association between the endometriosis and embryo quality. Searches were performed on the three electronic databases: PubMed, EMBASE, and Web of Science. The detailed characteristics and data of the included studies were extracted. The risk ratio with 95% confidence intervals were calculated using the random and fixed effects model. The main outcome measures were high-quality embryo rate, cleavage rate, and embryo formation rate. Results: A total of 22 studies included were analyzed. Compared with the control group, women with endometriosis had a similar high-quality embryo rate (RR = 1.00; 95% CI, 0.94–1.06), a comparable cleavage rate (RR = 1.00; 95% CI, 0.97–1.02), and a similar embryo formation rate (RR = 1.10; 95% CI, 0.97–1.24). In women with stage III-IV endometriosis, there was no statistically significantly difference in high-quality embryo rate (RR = 1.02; 95% CI, 0.94–1.10), cleavage rate (RR = 1.00; 95% CI, 0.98–1.02), and embryo formation rate (RR = 1.05; 95% CI, 0.97–1.14), compared with those without endometriosis. For women with unilateral endometrioma, pooling of results from the affected ovaries did not show a statistically significantly difference in high-quality embryo rate (RR = 0.99; 95% CI, 0.60–1.63) in comparison to the normal contralateral ovaries. Conclusions: Our results seem to indicate that endometriosis does not compromise embryo quality from the perspective of morphology.