Total and trimester-specific gestational weight gain and infant anthropometric outcomes at birth and 6 months in low-income Hispanic families

Objective: To describe total and trimester-specific gestational weight gain (GWG) among low-income Hispanic women and determine whether these GWG exposures are associated with infant anthropometric outcomes at birth and 6 months. Study Design: Data were from 448 mother-infant pairs enrolled in the Starting Early child obesity prevention trial. Prenatal weights were used to calculate total GWG and 2^nd and 3^rd trimester GWG rates (kg/week) and categorized as inadequate, adequate, and excessive according to the 2009 Institute of Medicine recommendations. Multivariable linear and modified Poisson regressions estimated associations of infant anthropometric outcomes (birthweight, small-for-gestational age [SGA], large-for-gestational age [LGA], rapid weight gain, and weight-for-age, length-for-age, and weight-for-length z-scores at 6 months) with GWG categories. Results: For total GWG, 39% and 27% of women had inadequate and excessive GWG, respectively. 57% and 46% had excessive GWG rates in the 2^nd and 3^rd trimesters, respectively, with 29% having excessive rates in both trimesters. Inadequate total GWG was associated with lower infant weight and length outcomes (ß range for z-scores = −0.21 to −0.46, p < 0.05) and lower risk of LGA (adjusted Relative Risk, aRR = 0.38; 95% confidence intervals, CI: 0.16, 0.95) and rapid weight gain (aRR = 0.72; 95%CI: 0.51, 1.00). GWG rates above recommendations in the 2^nd trimester or 2^nd/3^rd trimesters were associated with greater weight outcomes at birth and 6 months (ß range for z-scores = 0.24 to 0.35, p < 0.05). Conclusions: Counseling women about health behaviors and closely monitoring GWG beginning in early pregnancy is necessary, particularly among populations at high-risk of obesity.