“…We classified these covariates as demographic or potential confounders that may affect BMI, or fertility status in the NHANES database. 2 , 18 , 19 , 24 , 27 , 28 They were derived from self-reported data, examination data. Covariates included: age (18–45 years), race/ethnicity (Mexican-American, Other Hispanic, Non-Hispanic White, Non-Hispanic Black, Non-Hispanic Asian, Other Race), educational attainment (Less than high school, High school, More than high school), marital status (Married or Living with partner, Living alone), ratio of family income to poverty (ratio of household income to poverty indicators 29 ), alcohol consumption (at least 12 drinks of alcoholic beverages in the last year), active smoking (at least 100 cigarettes/year), diabetes mellitus, hypertension, and prior pregnancy.…”