Low Birth Weight Across Generations: The Effect of Economic Environment

Abstract

To determine whether economic environment across generations underlies the association of maternal low birth weight (<2,500 g, LBW) and infant LBW including its preterm (<37 weeks) and intrauterine growth retardation (IUGR) components. Stratified and multilevel logistic regression analyses were performed on an Illinois transgenerational dataset of White and African-American infants (1989-1991) and their mothers (1956-1976) with appended US census income data. Population Attributable Risk percentages were calculated to estimate the percentage of LBW births attributable to maternal LBW. Among Whites, former LBW mothers (N = 651) had an infant LBW rate of 7.1% versus 3.9% for former non-LBW mothers (N = 11,505); RR = 1.8 (1.4-2.5). In multilevel logistic regression models that controlled for economic environment and individual maternal risk factors, the adjusted OR of infant LBW, preterm birth, and intrauterine growth retardation for maternal LBW (compared to non-LBW) equaled 1.8 (1.3-2.5), 1.3 (1.0-1.8), and 1.8 (1.5-2.3), respectively. Among African-Americans, former LBW mothers (N = 3,087) had an infant LBW rate of 19.5% versus 13.3% for former non-LBW mothers (N = 18,558);RR = 1.5 (1.3-1.6). In multilevel logistic models of African-Americans, the adjusted OR of infant LBW, preterm birth, and IUGR for maternal LBW (compared to non-LBW) were 1.6 (1.4-1.8), 1.3 (1.2-1.5), and 1.6 (1.5-1.8), respectively. In both races, approximately five percent of LBW infants with mothers and maternal grandmother who resided in high-income neighborhoods were attributable to maternal LBW. A similar generational transmission of LBW including its component pathways of preterm birth and intrauterine growth retardation occurs in both races independent of economic environment across generations.