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: <131.2, 131.2-178.0, 178.0-242.9, and >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.
Keywords: Depot gonadotropin-releasing hormone agonist long protocol; Estradiol/oocyte ratio; Live birth; Ovarian stimulation; Pregnancy.
© 2020 International Federation of Gynecology and Obstetrics.