This study reviewed the impact of endometriosis and its staging on assisted reproduction outcomes through a systematic review and meta-analysis. It found that while the presence of endometriosis did not affect clinical pregnancy or live birth rates, it was associated with a higher risk of miscarriage and fewer retrieved oocytes. More severe endometriosis (Stage III/IV) was also linked to fewer retrieved oocytes than less severe (Stage I/II) endometriosis.