Socio-economic status and z-score standardized height-for-age of US-born children (ages 2-6)

This study explores socio-economic gradients in height (stature-for-age) among a nationally representative sample of 2-6 year old children in the United States. We use NHANES 111 (1988-1994) Youth data linked with a special Natality Data supplement which contains information from birth certificates among sampled NHANES III Youth who are <7 years of age. Our results indicate significant socio-economic gradients for both maternal education and family income, net of controls for confounders, including: birth weight, gestational age, family size, and parental heights. These results are in stark contrast to those from other developed countries that seem to indicate diminished or eliminated socio-economic disparities, net of known confounders. In the United States, it appears that socio-economic gradients have an effect on birth outcomes, and continue to have an additional direct and independent effect on height, even in early childhood. (C) 2011 Elsevier B.V. All rights reserved.