Reproductive Health Disparities in the USA: Self-Reported Race/Ethnicity Predicts Age of Menarche and Live Birth Ratios, but Not Infertility

Self-identified race/ethnicity and socioeconomic status (SES) contribute to disparities in several health domains, although research on their effects on women's reproductive function has largely focused on links between SES and age of menarche. Here, we assessed whether race/ethnicity, SES, and downstream correlates of SES such as food security and health-insurance security are associated with age of menarche, infertility, and live birth ratios (ratios of recognized pregnancies resulting in live births) in the USA. We used cross-sectional data from 1694 women aged 12-18 years for menarche (2007-2016), 974 women aged 23-45 for infertility (2013-2016), and 1714 women aged 23-45 for live birth ratios (2007-2016) from the National Health and Nutrition Examination Survey. We estimated multiple linear and logistic regressions with survey weights to test these associations. When controlling for lifestyle (activity levels, smoking, alcohol consumption) and physiological factors (diabetes, weight status), non-Hispanic (NH) black and Hispanic girls reported a significantly lower age of menarche by about 4.3 (standard error [SE] = 0.08, p < 0.001), and 3.2 months (SE = 0.09, p < 0.001), respectively, relative to NH white girls. NH black women reported live birth ratios 9% (SE = 0.02, p < 0.001) lower than NH white women. Women with unstable health insurance reported live birth ratios 6% (SE = 0.02, p = 0.02) lower than women with stable health insurance. Race/ethnicity, SES, and its downstream correlates were not associated with infertility. One hypothesized explanation for observed disparities in age of menarche and live birth ratios is the embodiment of discrimination faced by NH black women within the USA. Our findings also underscore the importance of health insurance access for favorable reproductive health outcomes. Future work should elucidate the role of embodied discrimination and other downstream correlates of SES in modulating women's reproductive health outcomes to inform strategies to mitigate health disparities.