Maternal Body Mass Index Modifies The Impact Of Negative Energy Balance During Lactation On Infant Weight And Length Gain In Hiv-Exposed, Uninfected Malawian Females

Negative maternal energy balance during lactation may influence growth of exclusively breastfed infants through impaired quality or quantity of breastmilk. Malawian mother‐infant pairs (n=1,449) in the Breastfeeding, Antiretrovirals and Nutrition Study were randomized to receive a lipid‐based nutrient supplement (LNS), meeting nutritional needs of lactation, or no LNS and a maternal, infant or no antiretroviral (ARV) regimen. Linear regression models were used to relate negative maternal energy balance (weight loss 2–24 weeks) to infant weight and length gain from birth to 24 weeks, stratifying by gender and maternal BMI at 2 weeks (mean: 23.1 kg/m2), and controlling for birth measurement, parity, treatment arm and seasonality. Length (β: −3 cm, p=0.01) and weight gain (β: −1.3 kg, p=0.001) were lower in girls whose mothers had lower BMI at 2 weeks postpartum coupled with negative energy balance, compared to women in positive energy balance. Treatment arm was not associated with infant length or weight gain (p>0.13). Though effects were only observed in girls, suggesting possible gender differences in suckling and feeding behavior, these findings indicate that maternal negative energy balance with low energy reserves represents a risk factor for poor infant growth outcomes, possibly through reduced milk energy output. Grant Funding Source : CDC(U48 DP000059 01); Bill & Melinda Gates Foundation ( OPP53107 ); CPC(NICHD 5 R24 HD050924 )