Assessment of oocyte quality in polycystic ovarian syndrome and endometriosis by spindle imaging and reactive oxygen species levels in follicular fluid and its relationship with IVF-ET outcome

OBJECTIVES: The aim of this study is to examine meiotic spindle in oocytes along with reactive oxygen species (ROS) levels in follicular fluid of women undergoing IVF and to correlate these findings with embryo quality and pregnancy outcome. MATERIALS AND METHODS: 167 women aged 25–35 years with endometriosis (Group A), polycystic ovarian syndrome (PCOS) (Group B) and tubal block (Group C) were included. Long protocol downregulation using recombinant follicular stimulating hormone was used for ovarian stimulation. Aspirated follicular fluid containing mature oocytes were analyzed for ROS levels and the oocytes were assessed for the presence of meiotic spindle using Cri-Oosight™ Polscope. Fertilization, embryo quality, endometrial assessment, and final pregnancy outcome were assessed. RESULTS: Meiotic spindles were visualized in a higher proportion of mature oocytes retrieved from women with endometriosis (66%) as compared to those with PCOS (50.5%) and tubal block (62.3%). ROS levels were also observed to be significantly less in the follicular fluid of oocytes in women with endometriosis (Group A) as compared to the other two groups (P ≤ 0.001). However, pregnancy rates were observed to be lower in Group A (32%) than Groups B (39%) and C (44%), respectively. Within each group, oocytes with spindle visualization yielded a higher number of Grade 1 embryos (P < 0.05) as well as lower ROS levels in follicular fluid (P ≤ 0.001) as compared to those where spindle could not be visualized. CONCLUSIONS: There was good correlation between spindle imaging and ROS levels as reliable predictors of oocyte assessment. Women with endometriosis had low ROS levels and good spindle imaging results suggesting a possible role of endometrial receptivity accounting for lower pregnancy rates in these women. Poor oocyte quality, as reflected by higher mean ROS levels and low number of oocytes with spindle visualization, could be the factor impeding pregnancy in women with PCOS as compared to women with tubal block.