Formula-feeding of HIV-exposed uninfected African children is associated with faster growth in length during the first six months of life in the Kesho Bora study

Background: Early feeding patterns may affect growth of HIV-exposed children and thus their subsequent health and cognition. Objective: An observational cohort study assessed the association of infant feeding mode (IF) with length-for-age z-score (LAZ) and stunting from age 2 days to 18 months in HIV-exposed African children within the Kesho Bora controlled randomized trial which evaluated triple antiretrovirals initiated during pregnancy and continued for six months postpartum to prevent HIV transmission.Methods: HIV-infected pregnant women with CD4+ counts 200-500 cells/mm3 from five sites in Burkina Faso, Kenya and South Africa were advised to exclusively breastfeed (EBF) for up to six months or formula-feed (FF) from birth. Factors associated with mean LAZ and change in LAZ with increasing age were investigated in all uninfected children using mixed-effects linear models; those associated with stunting (LAZ<-2) at 6 or 12 months were assessed in multiple logistic regression after exclusion of children stunted at age 2 days. Independent variables were IF: FF, EBF<3 months or EBF ?3 months (reference), sex, trial arm, maternal characteristics, and site. Results: Among 728 children, FF was associated with a greater increase in LAZ from 2 days to 6 months (+0.07 z-score/month, P<0.001). Between 6 and 18 months, FF and EBF <3 months were both associated with greater mean LAZ than EBF ?3 months (+0.52 z-scores and +0.43 z-z-scores, respectively, P<0.001). Among children not stunted at 2 days, FF was independently associated with reduced risk of stunting at 6 months (OR: 0.24; 95% CI: 0.07, 0.81; P: 0.021), while EBF<3 months was not (OR: 0.49; 0.22, 1.10; P: 0.09). Conclusion: In this observational study of HIV-exposed uninfected infants, growth in length in the first six months of life was faster in FF infants than in EBF infants. The plausibility of residual confounding and reverse causality is discussed.This trial was registered at Current Controlled Trials as ISRCTN71468401