Increased neonatal fat mass, not lean body mass, is associated with maternal obesity.

OBJECTIVE: The purpose of this study was to compare body composition measures in neonates of women who were overweight/obese (body mass index, > or = 25 kg/m2) versus women who were lean/average (body mass index, < 25 kg/m2), all of whom had normal glucose tolerance levels. STUDY
DESIGN: Seventy-six neonates (34 female and 42 male) of singleton pregnancies of pregravid overweight/obese women and 144 neonates (67 female and 77 male) of lean/average women were assessed with anthropometric measures and total body electrical conductivity evaluation of body composition at birth.
RESULTS: There was a borderline increase in birthweight (3436 +/- 567 g vs 3284 +/- 534 g; P = .051) but not lean body mass (3020 +/- 410 g vs 2950 +/- 400 g; P = .23) in the overweight/obese versus lean/average weight groups. However, there were significant increases in percent body fat (11.6% +/- 4.7% vs 9.7 +/- 4.3%; P = .003) and fat mass (420 +/- 220 g vs 380 +/- 170 g; P = .01) in neonates of overweight/obese women versus lean/average weight women.
CONCLUSION: Overweight/obese women with normal glucose tolerance levels have neonates who are heavier than lean/average weight women because of increased adiposity. We speculate that this increased obesity in offspring of obese women with normal glucose tolerance levels is a significant risk for adolescent obesity and components of the metabolic syndrome.