Birth weight, infant mortality, and race: twin comparisons and genetic/environmental inputs.

Genetic and environmental inputs may shape population health disparities in varying ways. In this article, we use unique variation involved in twin births to attempt to untangle how genetic and prenatal environmental variation may make different contributions to infant health among white and black populations in the United States. Using twin fixed effects models and data from the 1995-1997 Matched Multiple Birth Dataset we compare birth weight-mortality associations across twin sex composition, zygosity, and race. Findings reveal suggestive differences between fraternal and imputed identical twin estimates for white and black twin pairs.