Growth faltering due to breastfeeding cessation in uninfected children born to HIV-infected mothers in Zambia

Background: The effect of breastfeeding on growth in HIV-exposed infants is not well described. Objective: The objective was to evaluate the effect of early breastfeeding cessation on growth. Design: In a trial conducted in Lusaka, Zambia, HIV-infected mothers were randomly assigned to exclusive breastfeeding for 4 mo followed by rapid weaning to replacement foods or exclusive breastfeeding for 6 mo followed by introduction of complementary foods and continued breastfeeding for a duration of the mother's choice. Weight-for-age z score (WAZ), length-for-age z score (LAZ), and weight-for-length z score (WLZ) and the self-reported breastfeeding practices of 593 HIV-uninfected singletons were analyzed. Generalized estimating equations were used to adjust for confounders. Results: WAZ scores declined precipitously between 4.5 and 15 mo. The decline was slower in the breastfed infants. At 9, 12, and 15 mo, mean WAZs were, respectively, -0.74, -0.92, and -1.06 in infants who were reportedly breastfed and were -1.07, -1.20, and -1.31 in the weaned infants (P = 0.003, 0.007, and 0.02, respectively). No differences were observed past 15 mo. Breastfeeding practice was not associated with LAZ, which declined from -0.98 to -2.24 from 1 to 24 mo. After adjustment for birth weight, maternal viral load, body mass index, education, season, and marital and socioeconomic status, not breastfeeding was associated with a 0.28 decline in WAZ between 4.5 and 15 mo (P < 0.0001). During the rainy season, not breastfeeding was associated with a larger WAZ decline (0.33) than during the dry season (0.22; P for interaction = 0.02). Conclusions: Early growth is compromised in uninfected children born to HIV-infected Zambian mothers. Continued breastfeeding partially mitigates this effect through 15 mo. Nutritional interventions to complement breastfeeding after 6 mo are urgently needed. This trial was registered at clinicaltrials.gov as NCT00310726.