Relationship between the oestradiol/oocyte ratio and the outcome of assisted reproductive technology cycles with gonadotropin releasing hormone agonist.

The aim of this study was to evaluate the relationship of oestradiol level on the day of hCG (peak E2)/oocyte ratio and the outcome of ART cycles. Of the patients who underwent IVF-ET, 600 normal and high responders to the first cycle of COH with gonadotropin releasing hormone (GnRH)-agonist were included in the study. Patients were designated into three groups based on peak E2/oocyte ratio (Group A: <100 pg/ml per oocyte, Group B: 100-200 pg/ml per oocyte, Group C: >200 pg/ml per oocyte). A comparison among groups was made regarding ovarian stimulation characteristics, fertilisation, implantation and pregnancy rates. After the division based on E2/oocyte ratio, in Group C, the number of oocytes retrieved, 2PN and M2 oocyte were statistically lower than both of the other two groups (p = 0.001, 0.001, 0.001, 0.045). HCG day E2 level was significantly different in all groups (p = 0.001), and fertilisation rate was meaningfully highest in Group C and lowest in Group A (p = 0.001). No difference existed among the three groups with respect to the number of embryos transferred and implantation rates. However, clinical pregnancy rate was significantly lower in Group A than others (p = 0.04). In ART cycles suppressed by GnRH-agonist, IVF outcomes are lower in patients with an E2/oocyte proportion of <100 pg/ml per oocyte.