Blastocyst formation rate for Asians versus Caucasians and within body mass index categories

Purpose: There are well-documented racial and ethnic disparities for in vitro fertilization (IVF) outcomes, including disparities in clinical pregnancy and live birth rate. Obesity has also been associated with an increase in the risk of infertility and reduction in the efficacy of fertility treatment. However, there are limited data regarding the potential effect of race and obesity on in vitro embryo development. The purpose of this study was to determine whether blastocyst formation rates vary with race and body mass index (BMI). Methods: This retrospective analysis included 1134 fresh autologous cycles (N = 8266 embryos), which took place from January 2013 to December 2016. Women were categorized as Caucasian, Asian (not Indian), and Indian (South Asian) and by BMI categories (normal, overweight, and obese). Regression analyses were performed using race and BMI as the primary predictor variables and blastocyst formation as the outcome. Results: Compared to Caucasian, the adjusted OR for blastocyst development was 0.85 (95% CI 0.72–1.00) for Asian women and 1.15 (95% CI 0.95–1.38) for Indian women. Women who were overweight (aOR 0.93; 95% CI 0.77–1.12) or obese (aOR 0.92; 95% CI 0.74–1.12) had similar odds of blastocyst formation comparing to women with normal BMI. Furthermore, analyses examining combined effects of race and BMI revealed no differences in blastocyst formation among Asian or Indian women with varied BMI categories compared to Caucasian women with normal BMI. Conclusion: Blastocyst formation did not differ based on race or BMI.