The US population is increasingly diverse, and many racial and ethnic groups suffer from disparities in fertility, fertility care, and during assisted reproduction. In an effort to reduce and ultimately eliminate health disparities in the United States, the National Institutes of Health (NIH) requires collection and reporting of data on race and ethnicity for all NIH-supported clinical research. Collecting this data assumes an accurate definition of “race.” The NIH uses the same categories as other US federal agencies, but those are sociopolitical constructs and are not biologically based. Traditional concepts of race and ethnicity are brought into question in the post-genomic era. Single nucleotide polymorphisms that have different frequencies between groups are called Ancestry Informative Markers and may be of use in categorizing research participants. Ongoing extensive research into Developmental Origins of Health and Disease provides a framework for an epigenetic, transgenerational source of health disparities in disadvantaged groups and may provide further insight into the perpetuation of disparities in racial and ethnic groups. Consideration of genetic ancestry and epigenetic markers in addition to self-identified race and ethnicity may help to untangle and identify the complex interplay of disease and disparity in fertility research.