Endometriosis Affects Oocyte Morphology in Intracytoplasmic Sperm Injection Cycles

To identify associations between presence of endometriosis and oocyte defects, embryo developmental potential, and cycle outcomes.This study looked into the impact of endometriosis on oocyte and embryo quality, and blastocyst formation probability. Endometriosis was also correlated with cycle characteristics. In order to avoid age-related bias, in the first analysis only patients aged 36 years or younger were included, and the cycles were split into endometriosis infertility cycles (n=431; 3172 oocytes) and other cycles (n=2510; 24480 oocytes).The number of retrieved oocytes (10.6±21.2 vs. 14.6±21.1, P<0.001), oocyte yield (68.1±20.0% vs. 70.6±19.6%, P=0.015), and embryos obtained (6.1±4.43 vs. 7.8±5.12, P<0.001) were lower among patients with endometriosis. Implantation rates (28.1%±38.9% vs. 33.9±42.7, P<0.001) were lower among patients with endometriosis, but fertilization, pregnancy, miscarriage and cycle cancelation rates were not different. There was a significant increase in the incidence of extra-cytoplasmic, but not intra-cytoplasmic, oocyte defects among patients with endometriosis. The quality of embryos (45.3% vs. 47.3%, P=0.037) collected from patients with endometriosis was lower, but blastocyst formation rates were unaltered.A possible explanation for the lower implantation rates seen in patients with endometriosis is the poorer quality of the oocytes and embryos observed in this group of patients.