Background: HIV-exposed uninfected (HEU) children experience increased mortality compared with their HIV-unexposed uninfected (HUU) peers. It is unclear whether HEU children are also at increased risk for undernutrition, a modifiable risk factor for mortality.

Methods: We conducted a cross-sectional, population-based survey of children <5 years of age in 5 health districts in Botswana. Linear mixed-effects models were used to assess continuous outcomes, and generalized estimating equations were used to estimate relative risks of stunting, wasting, and underweight between HEU (n = 396) and HUU (n = 1109) children. Secondary analyses examined potential mediation by low birth weight.

Results: The association between maternal HIV exposure and child stunting varied significantly by child age (P < 0.01). HEU children <1 and ≥2 years of age had 1.85 [95% confidence interval (CI): 1.03 to 3.31; P = 0.04] and 1.41 (95% CI: 1.06 to 1.88; P = 0.02) times the risk of stunting compared with HUU children after multivariate adjustment, respectively. During the period of 1-2 years of age, when breastfeeding cessation occurred among HUU children, HUU children had increased risk of stunting compared with HEU children who were predominantly formula fed (relative risk: 1.56; 95% CI: 1.05 to 2.32; P = 0.03). A mediation analysis estimated that 67% of the excess risk of stunting among HEU children ≥2 years was attributable to low birth weight (P = 0.02). There was no difference in risk of wasting or underweight.

Conclusion: HEU children are at increased risk of stunting compared with their HUU peers; however, interventions to increase birth weight may significantly ameliorate this excess risk. Interventions to support optimal growth during weaning are needed for all breast-fed children.