Racial and ethnic differences in assisted reproduction treatment outcomes: the benefit of racial admixture

The goal of the present study was to determine whether racial and ethnic differences affect the outcomes of assisted reproductive technology in the Brazilian population. 1497 patients undergoing intracytoplasmic sperm injection (ICSI) cycles were split into groups according to the patient's ethnicity: Caucasian (n = 2131), Mestizo (n = 358), Asian (n = 174), Black (n = 115) and Indian (n = 260). ICSI outcomes were compared among the groups. Body mass index was highest in the Black group, followed by the Mestizo, Indian, Caucasian and Asian groups (p > 0.001). The FSH dose (p > 0.001) was highest among Indians, followed by Asians and Caucasians, and the dose was lowest among Blacks and Mestizos. In contrast, the oocyte yield was highest among Mestizos, followed by Indians, Blacks and Caucasians, and lowest among Asians (p = 0.005). The fertilisation rate was highest among Mestizos, followed by Blacks, Indians and Caucasians, whereas Asians had the lowest fertilisation rate (p = 0.004). Pregnancy and implantation rates were also highest among Mestizos, followed by Blacks, Indians and Caucasians, whereas the Asian patients had the lowest rates (p = 0.008 and p > 0.001, respectively). In conclusion, our evidence suggests a possible beneficial effect of racial admixture on ICSI outcomes.