Relation of parental birth weights to infant birth weight among African Americans and whites in Illinois: a transgenerational study.

The authors used a transgenerational data set of Illinois vital records to ascertain the relation between parental birth weights and infant birth weight. The infant generation consisted of all African Americans and whites born in Illinois during 1989-1991. The parent generation included the mothers and fathers who were also born in Illinois between 1956 and 1975. In the infant cohort, the rate of low birth weight (LBW) (<2,500 g) was 11.7% for African Americans (n = 15,287) versus 5.0% for whites (n = 117,708) (relative risk (RR) = 2.3, 95% confidence interval (CI) 2.2-2.5). For African Americans, the LBW rate was 17.9% among those born to LBW mothers (n = 1,943) compared with 10.8% among those born to non-LBW mothers (n = 13,344) (RR = 1.8, 95% CI 1.6-1.9). For whites, the LBW rate was 8.5% among those born to LBW mothers (n = 2,174) compared with 4.8% among those born to non-LBW mothers (n = 115,534) (RR = 1.7, 95% CI 1.6-2.0). A weaker association was observed between paternal birth weight and infant birth weight. The authors conclude that parental birth weights are important risk factors for LBW in both African Americans and whites.