Racial Variation in Semen Quality at Fertility Evaluation.

OBJECTIVE To identify racial differences in semen quality among men living in the same geographic area and seeking fertility evaluation. METHODS Men obtaining a semen analysis for infertility evaluation or treatment between 2012 and 2016 at a single center were identified, and demographic data including height, weight, body mass index (BMI), and age were described. Mean semen parameters and the proportions of men with suboptimal parameters based on the World Health Organization's fifth edition criteria were also compared based on race. Multivariable regression analysis was conducted incorporating age, BMI, and year of evaluation. Further subanalyses based on BMI were subsequently performed. RESULTS White men produced greater volumes of semen on average; however, Asian men had higher sperm concentrations and total sperm count. A lower proportion of Asian men compared to white men had semen quality in the suboptimal range for most semen parameters, whereas a higher proportion of white men were found to have azoospermia. Stratification by BMI groups attenuated the observed differences between whites and Asians, yet Asian male semen quality remained higher. CONCLUSION Among men evaluated for infertility at a single center, Asians had lower volume but higher sperm concentrations compared with whites, which was influenced by differences in azoospermia prevalence. Although anthropometric and demographic factors attenuated the differences, even after adjustment, the contrasts remained. Our study suggests that racial differences exist in semen quality at the time of infertility evaluation.