The estradiol/oocyte ratio predicts the MII oocyte rate, but not live-birth rate in a depot gonadotropin-releasing hormone agonist long protocol

OBJECTIVE To investigate whether the estradiol/oocyte ratio (E2 /O) can predict ovarian response and pregnancy outcomes. METHODS This is a retrospective cohort study on 1838 individuals undergoing in vitro fertilization with a depot gonadotropin-releasing hormone agonist (GnRH-a) long protocol. The patients were grouped by the quartiles of E2 /O: 242.9 pg/mL. ANOVA and χ2 test with the Bonferroni adjustment were used for statistical analysis. RESULTS With the rise of E2 /O, the MII oocyte rate increased, whereas the number of oocytes retrieved decreased. The number of MII oocytes, fertilization rate, and the number of high-grade embryos were similar among the four groups. There were no differences in live-birth rate, clinical pregnancy rate, ectopic pregnancy rate, and miscarriage rate, but there was a trend towards a higher miscarriage rate in the patients with E2 /O between 131.2 and 242.9 pg/mL. CONCLUSION E2 /O indicates the percentage of MII oocytes, but not the quality of an individual follicle. E2 /O does not predict live birth in a depot GnRH-a long protocol; however, there is a trend towards a higher risk for miscarriage in the patients with E2 /O between 131.2 and 242.9 pg/mL.