Asian ethnicity in anonymous oocyte donors is associated with increased estradiol levels but comparable recipient pregnancy rates compared with Caucasians

ObjectiveTo determine if differences exist in ovarian response and pregnancy rates between Asian and Caucasian donors.DesignRetrospective cohort study.SettingUniversity-based clinic.Patient(s)Anonymous oocyte donors of self-reported Asian (n = 63) or Caucasian (n = 156) ethnicity who began ovarian stimulation between February 2000 and March 2008 and their matched recipients.Intervention(s)None.Main Outcome Measure(s)Recipient pregnancy rates and oocyte donor ovarian responsiveness.Result(s)Baseline characteristics were similar between Asian and Caucasian donors. Asian donors had peak serum estradiol levels that were 23% higher than their Caucasian counterparts (3715 ± 220 vs. 3013 ± 114 pg/mL). Adjusted estradiol levels per follicle measured and per oocyte retrieved were elevated in Asian donors (17% and 23% higher, respectively), and these differences were unchanged after adjusting for body mass index. No differences were noted in implantation rates (47.4% vs. 40.9%), clinical pregnancy rates (60.3% vs. 62.4%), or live-birth rates (55.5% vs. 59.9%) achieved using Asian vs. Caucasian oocyte donors.Conclusion(s)In contrast to autologous fresh in vitro fertilization cycles, Asian ethnicity is not associated with a lower pregnancy rate in recipient women using controlled hormone replacement when anonymous donor oocytes are used. Asian donors achieved statistically significantly higher serum estradiol levels during gonadotropin stimulation, suggesting an ethnic difference in steroid production and/or metabolism.