Racial/Ethnic Variation in Ovarian Responsiveness and Live Birth After In Vitro Fertilization.

OBJECTIVE 1) To evaluate racial/ethnic variation in ovarian responsiveness to stimulation during in vitro fertilization (IVF) and 2) to compare the association between ovarian responsiveness and live birth by race/ethnicity DESIGN: Retrospective cohort study SUBJECTS: Women who underwent ovarian stimulation for IVF between 2017-2019 as reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System.

EXPOSURE 1) Race/ethnicity (Asian, Black, Hispanic, Other/Mixed, White); 2) ovarian sensitivity index (OSI) MAIN OUTCOME MEASURES: 1) OSI (number of oocytes retrieved / total gonadotropin dose x 1000) adjusting for age at retrieval, body mass index, reporting year, number of prior cycles, Anti-Mullerian Hormone, and infertility diagnosis; 2) cumulative live birth adjusting for the above confounders and stratified by race/ethnicity RESULTS: A total of 246,132 retrieval cycles with race/ethnicity data were included: 46,939 (19.1%) among Asian patients, 17,013 (6.9%) among Black, 18,334 (7.4%) among Hispanic, 2,817 (1.1%) among Other/Mixed, and 161,029 (65.4%) among White. Adjusting for confounders, Black participants had a higher OSI compared to White participants (5.4, 95% CI 5.3-5.5, versus 5.1, 95% CI 5.1-5.1, p<0.001) and Asian participants had a lower OSI (4.8, 95% CI 4.7-4.8, p<0.001). Of the retrieval cycles, 68,107 resulted in fresh embryo transfers, and a total of 169,405 frozen embryo transfers were performed. Despite higher OSI, Black participants had lower cumulative live birth compared to White participants (45.5% versus 60.8%, p<0.001). When stratifying by race/ethnicity, higher OSI was consistently associated with an increased odds of cumulative live birth (adjusted odds ratio [aOR] ranging from 1.23, 95% confidence interval [CI] 1.02-1.48, for Other/Mixed to 1.49, 95% CI 1.45-1.53, for White), with no significant difference in the strength of association by race/ethnicity (interaction p=0.33).

CONCLUSION Higher ovarian responsiveness is associated with increased odds of cumulative live birth. However, despite higher ovarian responsiveness to stimulation, Black participants experience lower odds of cumulative live birth compared to White participants. This disparity in IVF outcomes likely arises from factors beyond differences in responsiveness to stimulation.