Black/White Differences in the Relationship of Maternal Age to Birthweight: A Population-Based Test of the Weathering Hypothesis

This study seeks to explore whether early health deterioration ('weathering') among young adult African American women contributes to observed increases with maternal age of the black/white disparity in birth outcome. Theoretically, 'weathering' is constructed as being a physical consequence of social inequality. Thus, the author examines whether African American mothers vary in their age trajectories of poor birth outcome with respect to social class. Black or white singleton first births to Michigan residents aged 15-34 in 1989 (N=54,888 births) are analyzed, using data drawn from linked birth and infant death certificates augmented with census-based economic information. The study finds that among blacks, but not whites, advancing maternal age above 15 years is associated with increased odds of LBW and VLBW. Among blacks in low-income areas, the odds of LBW increase three-fold, and of VLBW four-fold, between maternal ages 15 and 34. The findings suggest that African American women, on average, and those residing in low-income areas, in particular, experience worsening health profiles between their teens and young adulthood, contributing to their increasing risk of LBW or VLBW with advancing maternal age and to the black-white gap in this risk. The findings suggest the importance of comprehensive prevention strategies to improve the health of socioeconomically disadvantaged African American women prior to pregnancy and the reduction of social inequalities that impact health.