The Effects of Endometriosis on Oocyte and Embryo Quality

Endometriosis is a complex and multifaceted gynecological disorder characterized by the abnormal growth and presence of endometrial-like tissue outside the confines of the uterine cavity. It can lead to a wide range of distressing symptoms, including chronic pelvic pain, heavy and/or irregular menstrual bleeding, and significant challenges with fertility. While the association between endometriosis and infertility is well recognized, the precise mechanisms through which the disease affects oocyte and embryo quality remain controversial. Studies that utilized transcriptomic, metabolomic, and ultrastructural analyses indicated dysregulated energy metabolism, oxidative stress, mitochondrial dysfunction, and inflammatory alterations in the ovarian microenvironment. The impact of endometriosis on fertilization, embryo development, and implantation remains debated, with conflicting findings across different study designs. Some investigations reported impaired oocyte morphology, reduced fertilization rates, and poorer embryo quality, while others suggested that endometriosis does not significantly affect ART outcomes when confounding factors are controlled. Recent studies highlight the importance of distinguishing the disease severity, lesion location, and prior surgical interventions when assessing reproductive outcomes. The need for standardized methodologies in evaluating oocyte and embryo quality, alongside personalized treatment approaches, is emphasized. Further research is warranted to elucidate the precise molecular mechanisms underlying these effects and to develop targeted therapeutic strategies aimed at improving ART success in women with endometriosis. This narrative review provides a thorough examination of the previous research on the impact of endometriosis on oocyte and embryo quality, highlighting both the known mechanisms and the areas that require further investigation. This will help to guide future research and clinical management strategies to improve reproductive outcomes for women with endometriosis.