Intergenerational change in birthweight: Effects of foreign-born status and race/ethnicity

Background: Foreign-born women have heavier infants than US-born women, but it is unclear whether this advantage persists across generations for all races and ethnicities. Methods: Using 1971-2015 Florida birth records, we linked records of female infants within families to assess intergenerational changes in birthweight and prevalence of low birthweight by grandmother's race/ethnicity and foreign-born status. We also assessed educational gradients in low birthweight in two generations. Results: Compared with daughters of US-born black women, daughters of foreign-born black women had substantially higher birthweights (3,199 vs. 3,083 g) and lower prevalence of low birthweight (7.8% vs. 11.8%). Daughters of foreign-born Hispanic women had moderately higher birthweights (3,322 vs. 3,268 grams) and lower prevalence of low birthweight (4.5% vs. 6.2%) than daughters of US-born Hispanic women. In the next generation, a Hispanic foreign-origin advantage persisted in low birthweight prevalence (6.1% vs. 7.2%), but the corresponding black foreign-origin advantage was almost eliminated (12.2% vs. 13.1%). Findings were robust to adjustment for sociodemographic and medical risk factors. In contrast to patterns for other women, the prevalence of low birthweight varied little by maternal education for foreign-born black women. However, a gradient emerged among their US-born daughters. Conclusions: The convergence of birthweight between descendants of foreign-born and US-born black women is consistent with theories positing that lifetime exposure to discrimination and socioeconomic inequality is associated with adverse health outcomes for black women. The emergence of a distinct educational gradient in low birthweight prevalence between generations underscores hypothesized adverse effects of multiple dimensions of disadvantage.