P-320 The Effects of Endometriosis on Oocyte Morphology and Embryo Development

Study question What is the effect of the endometriosis on oocytes morphological abnormalities in intracytoplasmic sperm injection cycles.? Summary answer An increase in the detection rate of refractile body and polar body fragmentation was observed in the morphology of oocytes obtained from endometriosis patient. What is known already The quality of the oocyte is suspected for the lower clinical success in endometriosis patients compared to other patient groups. The oocyte quality is determined by its morphological, cellular, and molecular evaluations. However, there are limited studies on the association between endometriosis and oocyte morphology. Study design, size, duration This was a retrospective cohort study, conducted between January 2020 and August 2021, at a tertiary care hospital. The women aged 24-35 years and BMI 19-30 kg/m2 ranges who underwent fresh GnRH antagonist cycles and stimulated with 150-300 IU dose of recombinant FSH (rFSH) and then trigerred with 250 micrograms/0.5 ml of rhCG were included. Participants/materials, setting, methods The patients who were cycled with the etiology of endometriosis (n = 46 cycles, Group 1) and those who were cycled with the etiology of male infertility (n = 64 cycles, Group 2) were included in this study. In addition to the comparison of intracytoplasmic and extracytoplasmic (polar body, perivitelline space, zona pellisuda) anomalies observed in oocyte morphology between groups, morphology anomalies that affect fertilization and blastocyst development within the group were evaluated. Main results and the role of chance The patient age, BMI, antral follicle counts, duration of infertility, and basal endocrine parameters among patients who were cycled with the etiology of endometriosis (n = 46 cycles, Group 1) and those who were cycled with the etiology of male infertility (n = 64 cycles, Group 2) were not different (p>0.05). As a result of the comparison of intracytoplasmic anomalies of 800 oocytes in total (n = 263 Group 1; n = 537 Group 2) between the groups; the refractile body determination (OR:1.23; 95% CI 1.08 -1.4, p <0.00) was higher in the endometriosis group compared to the other group. As a result of the comparison of extracytoplasmic anomalies between the groups; the polar body fragmentation (OR:1.3; 95% CI 1.01 - 1.85, p> =0.03) determination was higher in the endometriosis group compared to the other group. When the effect of oocyte morphology anomalies on fertilization and blastocyst development within the groups was evaluated by logistic regression analysis, it was found that granulation of the perivitelline space had a negative effect on blastocyst development only in the endometriosis group (β = -0.69; p> =0.31). Limitations, reasons for caution The main limitation of our study was its retrospective design, which precludes us from reaching a more definitive conclusion on the relation between oocyte morphology of endometriosis an fertility outcomes. Wider implications of the findings The previous studies indicate that PVS and PBI abnormalities may be ascribed to over-mature oocytes and also be negatively correlated with fertilization rate and embryo quality. Our study suggest that endometriosis seems to negatively affect oocyte quality and maturation process. Trial registration number not applicable