Objective: The purpose of this study was to determine whether there is a difference in body composition and the factors that are associated with fat mass in the large-for-gestational-age infants of women with gestational diabetes mellitus compared with the large-for-gestational-age infants of women with normal glucose tolerance levels.
Study design: Large for gestational age was defined as weight >90th percentile for gestational age, race, and sex on the basis of our population's normative data. Anthropometric measurements and/or total body electrical conductivity estimated body composition that included fat mass, percent body fat, and lean body mass were obtained. Multiple stepwise regression was used to determine factors correlating with fat mass.
Results: Fifty cases of women with gestational diabetes mellitus and 52 cases of women with normal glucose tolerance levels were evaluated. Infants of mothers with gestational diabetes mellitus had increased fat mass (662 vs 563 g; P = .02) and percent body fat (16.2% vs 13.5%; P = .002) but decreased lean body mass (3400 vs 3557 g; P = .0009), as compared with infants of mothers with normal glucose tolerance levels, despite similar birth weights. Stepwise regression on all 102 women showed gestational age and a diagnosis of gestational diabetes mellitus correlated with fat mass (r2 = 0.11; P = .001). For gestational diabetes mellitus alone, both gestational age and fasting value of the oral glucose tolerance test correlated with fat mass and percent body fat (r2 = 0.33 [P = .0009] and r2 = 0.26 [P = .005], respectively).
Conclusion: Large-for-gestational-age infants of mothers with gestational diabetes mellitus have increased fat mass and decreased lean body mass compared with infants of mothers with normal glucose tolerance levels. In gestational diabetes mellitus, gestational age and fasting value of the oral glucose tolerance test correlated best with fat mass.