Birth weight in the United States: Disparities by race/ethnicity and maternal age

This dissertation examines social disparities in birth weight in the United States, specifically relating to how risk profiles vary by race/ethnicity and maternal age. The analysis uses the Early Childhood Longitudinal Study-Birth Cohort, a new nationally representative data set, combined with U.S. vital statistics records for supplementary analyses, to examine how age patterns in low birth weight (LBW) prevalence vary by race/ethnicity.Chapter 4 indicates that African American mothers not only have higher LBW risk than other racial/ethnic groups, but also exhibit a different LBW risk profile by age. While some disparities are clearly accounted for, such as the fact that the unfavorable birth outcomes of white teenage mothers are mostly explained by high smoking and low marriage rates, disparities among African American mothers in most cases persist controlling for social and physiological factors. U.S.-born and foreign-born Hispanic mothers exhibit a birth weight profile similar to that of white mothers. This research highlights that the factors contributing to LBW may be variable by racial/ethnic group.Chapter 5 examines birth weight using more refined weight categories. African American mothers show higher rates of very and moderately low birth weight compared to other racial/ethnic groups. Findings for high birth weight indicate that the effects of maternal age are largely linear, although disparities by race/ethnicity persist, with African American and Asian mothers having the lowest rates and white and Native American mothers having the highest rates.Chapter 6 finds that LBW prevalence increases with maternal age among African American first births, but not second or later births. Similar findings emerge for Native American mothers, but much less so among other racial/ethnic groups. These findings have strong theoretical importance in the fact that different norms in timing of first childbearing may be a meaningful factor in understanding birth outcome profiles within and across racial/ethnic groups.Overall, this dissertation found that maternal age is an important factor in understanding LBW disparities by race/ethnicity. Differing social environments may produce widely divergent birth outcomes by race/ethnicity, and this wide array of social factors must be considered in working to eliminate disparities in birth outcomes.