Ethnic group and reason for assisted reproductive technology failure: analysis of the Human Fertilisation and Embryology Authority registry data from 2017 to 2018.

OBJECTIVE: To understand how the risk of different assisted reproductive technology (ART) failure types varies by ethnic group and explore the role of mediation by maternal age and suspected etiology. DESIGN: An observational study of 48,750 women who undertook treatment with ART in the United Kingdom between January 2017 and December 2018. SETTING: The Human Fertilisation and Embryology Authority national ART registry of the United Kingdom. PATIENT(S): Women who commenced a first cycle of ART for the purpose of primary fresh embryo transfer using their own oocytes were included. INTERVENTION(S): Maternal ethnic group. MAIN OUTCOME MEASURE(S): The ART failure types were modeled on the maternal ethnic group using the Poisson regression to produce relative risks (RRs) with 95% confidence intervals. The potential indirect effects of maternal age and etiology of subfertility were estimated, and the RRs with 95% confidence intervals were produced. RESULT(S): Black women were at greater risk of treatment failure with respect to live birth than women who were white: cycle cancellation, RR of 2.15 (1.78-2.62); failed fertilization, RR of 2.36 (1.90-2.93); unintended freeze-all, RR of 1.71 (1.43-2.05); failed implantation, RR of 1.23 (1.12-1.34); and pregnancy loss, RR of 1.38 (1.15-1.64). Women who were Asian were at moderately increased risk: RRs of 1.31 (1.17-1.47), 1.60 (1.42-1.80), 1.25 (1.14-1.38), 1.11 (1.07-1.16), and 1.13 (1.03-1.23), across the same outcomes, respectively. Inequality may have been reduced had women of all ethnicities initiated treatment at the same age. CONCLUSION(S): Black women were at greatest risk of all failure types, and women who were Asian were at intermediate risk compared with women who were white. Some of the risks among women who were black may be mediated by maternal age.