Disproportionate alterations in body composition of large for gestational age neonates.

Abstract

The objective was to compare dual-energy x-ray absorptiometry-measured body composition between large (LGA) and appropriate (AGA) birth weight for gestational age neonates. LGA term infants (n = 47) with birth weights > or =4000 g were compared with 47 gestational age-matched AGA infants; 11 LGA infants were born to mothers with gestational (9) or pregestational diabetes (2). Dual-energy x-ray absorptiometry scans were performed at 1.8 +/- 1.0 days after birth. Body weight and length were the dominant predictors of body composition in LGA and AGA neonates. However, LGA neonates had significantly (P <.001, all comparisons) higher absolute amounts of total body fat, lean body mass, and bone mineral content and had significantly (P <.001, all comparisons) higher proportions of total body fat and bone mineral content but lower lean body mass as a percent of body weight. The changes for total body fat and lean body mass as a percent of body weight were greatest (P <.001) in LGA infants whose mothers had impaired glucose tolerance. LGA neonates have higher body fat and lower lean body mass than AGA infants. Impaired maternal glucose tolerance exaggerated these body composition changes.