Neonatal size of low socio-economic status Black and White term births in Albany County, NYS

Birth weight has long been a focus of study by epidemiologists and human bi ologists, because it reflects the quality of the intrauterine environment a nd may be used as a predictor of future growth and development. Comparisons of Black and White neonates in the USA have consistently shown differences in birth weight. Confounding variables are a major problem in any such inv estigation, especially socio-economic status which is highly correlated wit h race in the USA. This study was distinctive in the sampling of one socioe conomic stratum (low income), and the use of five anthropometric measures i n addition to birth weight. The goals of this study were as follows: to det ermine if there were differences in body size and body composition at birth in Black and White neonates of low socio-economic status (SES), and to inv estigate what variables might account for any observed variability. The sam ple consisted of full term Black and White neonates of low SES (n = 323) bo rn in Albany, NY (1986-1997). Birth weight, length, head and arm circumfere nce, and subscapular and triceps skinfolds were compared. Race was determin ed through maternal self-identification. White neonates were significantly larger than Black neonates in birth weight, length and head circumference. Among female neonates none of the anthropometric dimensions differed betwee n Blacks and Whites. Among male neonates, Whites were significantly larger than Blacks in birth weight, length, head and arm circumferences. Principal components analysis reduced the six anthropometric dimensions to two summa ry measures: body size and composition. When controlling for social and bio logical variables, race and sex were significant predictors of body composi tion, but not body size. Interpretation of results and possible causal rela tionships are discussed.