Objective: The objective was to compare dual-energy x-ray absorptiometry-me
asured body composition between large (LGA) and appropriate (AGA) birth wei
ght for gestational age neonates.
Study design: LGA term infants (n = 47) with birth weights greater than or
equal to 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.
Results: Body weight and length were the dominant predictors of body compos
ition in LGA and ACA neonates. Howel er, LGA neonates had significantly (P
< .001, all comparisons) higher absolute amounts of total body fat, lean bo
dy mass, and bone mineral content and had significantly (P < .001, all comp
arisons) 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 bod
y fat and lean body mass as a percent of body weight were greatest (P < .00
1) in LGA infants whose mothers had impaired glucose tolerance.
Conclusion: LGA neonates have higher body fat and lower lean body mass than
AGA infants. Impaired maternal glucose tolerance exaggerated these body co
mposition changes.