Race, ovarian responsiveness, and live birth after in vitro fertilization

Abstract

Objective: To determine if ovarian responsiveness to gonadotropin stimulation differs by race/ethnicity and whether this predicts live birth rates (LBRs) in non-White patients undergoing in vitro fertilization (IVF).

Design: Retrospective cohort study.

Setting: Academic infertility center.

Patient(s): White, Asian, Black, and Hispanic patients undergoing ovarian stimulation for IVF.

Intervention(s): Self-reported race and ethnicity.

Main outcome measure(s): The primary outcome was ovarian sensitivity index (OSI), defined as (the number of oocytes retrieved ÷ total gonadotropin dose) × 1,000 as a measure of ovarian responsiveness, adjusting for age, body mass index, infertility diagnosis, and cycle number. Secondary outcomes included live birth and clinical pregnancy after first retrievals, adjusting for age, infertility diagnosis, and history of fibroids, as well as miscarriage rate per clinical pregnancy, adjusting for age, body mass index, infertility diagnosis, duration of infertility, history of fibroids, and use of preimplantation genetic testing for aneuploidy.

Result(s): The primary analysis of OSI included 3,360 (70.2%) retrievals from White patients, 704 (14.7%) retrievals from Asian patients, 553 (11.6%) retrievals from Black patients, and 168 (3.5%) retrievals from Hispanic patients. Black and Hispanic patients had higher OSIs than White patients after accounting for those with multiple retrievals and adjusting for confounders (6.08 in Black and 6.27 in Hispanic, compared with 5.25 in White). There was no difference in OSI between Asian and White patients. The pregnancy outcomes analyses included 2,299 retrievals. Despite greater ovarian responsiveness, Black and Hispanic patients had lower LBRs compared with White patients, although these differences were not statistically significant after adjusting for confounders (adjusted odds ratio, 0.83; 95% confidence interval [CI], 0.63-1.09, for Black; adjusted odds ratio, 0.93; 95% CI, 0.61-1.43, for Hispanic). Ovarian sensitivity index was modestly predictive of live birth in White and Asian patients but not in Black (area under the curve, 0.51; 95% CI, 0.38-0.64) and Hispanic (area under the curve, 0.50; 95% CI, 0.37-0.63) patients.

Conclusion(s): Black and Hispanic patients have higher ovarian responsiveness to stimulation during IVF but do not experience a consequent increase in LBR. Factors beyond differences in responsiveness to ovarian stimulation need to be explored to address the racial/ethnic disparity established in prior literature.

Keywords: Racial disparity; gonadotropin dosing; in vitro fertilization; ovarian reserve; ovarian stimulation.