Weight gain in pregnancy and childhood body composition: findings from the Southampton Women's Survey.

BACKGROUND: Intrauterine life may be a critical period for the programming of later obesity, but there is conflicting evidence about whether pregnancy weight gain is an important determinant of offspring adiposity. OBJECTIVE: The purpose of this study was to examine the relation of pregnancy weight gain with neonatal and childhood body composition. DESIGN: The participants (n = 948) were children born to women in the Southampton Women's Survey who had dual-energy X-ray absorptiometry measurements of body composition at birth, 4 y, or 6 y. Pregnancy weight gain was derived from the mothers' measured weights before pregnancy and at 34 wk gestation and analyzed by using 2009 Institute of Medicine categories (inadequate, adequate, or excessive) and as a continuous measure. RESULTS: Almost one-half (49%) of the children were born to women who gained excessive weight in pregnancy. In comparison with children born to women with adequate weight gain, they had a greater fat mass in the neonatal period (SD: 0.17; 95% CI: 0.02, 0.32; P = 0.03), at 4 y (SD: 0.17; 95% CI: 0.00, 0.34; P = 0.05), and at 6 y (SD: 0.30; 95% CI: 0.11, 0.49; P = 0.002). Greater pregnancy weight gain, as a continuous measure, was associated with greater neonatal fat mass (SD: 0.10 per 5-kg weight gain; 95% CI: 0.04, 0.15; P = 0.0004) and was weakly associated with fat mass at 6 y (SD: 0.07 per 5-kg weight gain; 95% CI: 0.00, 0.14; P = 0.05) but not at 4 y (SD: 0.02 per 5-kg weight gain; 95% CI: -0.04, 0.08; P = 0.55). CONCLUSION: Appropriate pregnancy weight gain, as defined by 2009 Institute of Medicine recommendations, is linked to lower levels of adiposity in the offspring.