Oocyte quality in endometriosis-associated infertility: a narrative analysis of mechanisms and therapeutic options.

Endometriosis is a challenging gynaecological condition that can lead to infertility. This unique narrative review summarises the impact of endometriosis, focusing on oocyte quality, its subcellular and molecular mechanisms, clinical effects, and therapeutic options. The disease is associated with a hostile follicular microenvironment caused by inflammation, oxidative stress, granulosa and cumulus cell dysfunction, and hormonal dysregulation. It further leads to spindle disorders, mitochondrial DNA breakdown, and delayed cytoplasmic maturation. Women with stage III-IV endometriosis have low ovarian reserve, fewer retrieved and matured (MII) oocytes, and lower fertilisation and blastocyst development rates, resulting in worse cumulative pregnancy outcomes. However, when good-quality embryos are transferred, implantation and live birth rates are often similar to those of controls, suggesting that the problem is primarily oocyte-driven rather than endometrium-related. Therapeutic options include lifestyle modifications with a healthy diet, yoga, exercise, adequate sleep, and stress management, in addition to individualised assisted reproductive technology (ART) treatments, to enhance prognosis, though with sub-optimal proven mechanisms.