Differing intergenerational birth weights among the descendants of US-born and foreign-born whites and African Americans in Illinois

The authors analyzed Illinois vital records to determine the intergenerational birth weight patterns among the descendants of US-born and foreign-born White and African-American women. Among the descendants of the generation 1 US-born White women (n = 91,061), generation 3 females had a birth weight 65 g more than that of their generation 2 mothers (p < 0.0001); generation 3 infants had a 10% lower moderately low birth weight (1,500-2,499 g) rate than did their generation 2 mothers: 5.0% versus 5.5% percent, respectively (relative risk = 0.9, 95% confidence interval: 0.9, 0.9). Among the descendants of generation 1 European-born White women (n = 3,339), generation 3 females had a birth weight 45 g more than that of their generation 2 mothers (p < 0.0001). Among the descendants of generation 1 US-born African-American women (n = 31,699), generation 3 females had a birth weight 17 g more than that of their generation 2 mothers (p < 0.001). Among the descendants of generation 1 African/Caribbean-born women (n = 104), generation 3 females had a birth weight 57 g less than that of their generation 2 mothers; generation 3 females had a 40% greater moderately low birth weight rate than did their generation 2 mothers: 9.6% percent versus 6.7% percent (relative risk = 1.4, 95% confidence interval: 0.6, 3.6). Maternal age and marital status did not account for the birth weight trends. The authors conclude that the expected intergenerational rise in birth weight does not occur among the direct female descendants of foreign-born African-American women.