Growth trajectories of breastfed HIV-exposed uninfected and HIV-unexposed children under conditions of universal maternal antiretroviral therapy: a prospective study

Abstract

Background: Over 1 million HIV-exposed uninfected (HEU) children are born in sub-Saharan Africa annually. Little data exist on the risk of impaired growth in this population under current policies of universal maternal antiretroviral therapy (ART) with breastfeeding. We aimed to study the growth of breastfed HEU children born to women who initiated ART during pregnancy and compare their growth with that of breastfed HIV-unexposed (HU) children drawn from the same community.

Methods: A prospective cohort of HIV-uninfected and HIV-infected pregnant women, who were initiating ART, were enrolled at their first antenatal care visit in a primary care centre in Gugulethu, Cape Town, South Africa. HIV infected women were participants of the Maternal Child Health Antiretroviral Therapy (MCH-ART) study, and HIV-uninfected pregnant women were participants in the HIV-Unexposed-Uninfected (HU2) study. All women were followed up during pregnancy, through delivery, to the early postnatal visit, which was scheduled for the first week after birth. At this visit, eligible breastfeeding mother-child pairs were recruited for continuation of postnatal follow-up until approximately age 12 months. Child anthropometry was measured at around 6 weeks, and every 3 months from month 3 to month 12. Weight-for-age (WAZ), length-for-age (LAZ), weight-for-length (WLZ), head circumference-for-age, and body-mass index-for-age Z scores were compared between HEU and HU children longitudinally using mixed effects linear regression. At 12 months, proportions of HEU and HU children with moderate or severe malnutrition were compared cross-sectionally using logistic regression. MCH-ART is registered with ClinicalTrials.gov, number NCT01933477.

Findings: Between June, 2013, and April, 2016, 884 breastfeeding mothers and their newborn babies (HEU, n=471; HU, n=413) were enrolled into postnatal follow-up. Excluding 12 children who tested HIV positive during follow-up, 461 HEU and 411 HU children attended 4511 study visits in total, with a median of 6 visits (IQR 5-6) per child. Birth characteristics were similar (overall, 94 [11%] of 872 preterm [<37 weeks] and 90 [10%] small-for-gestational age [birthweight <10th percentile]). Median duration of breastfeeding was shorter among HEU than HU children (3·9 months [IQR 1·4-12·0] vs 9·0 months [IQR 3·0-12·0]). Although WAZ scores increased over time in both groups, HEU children had consistently lower mean WAZ scores than HU children (overall β -0·34, 95% CI -0·47 to -0·21). LAZ scores decreased in both groups after 9 months. At 12 months, HEU children had lower mean LAZ scores than HU children (β -0·43, -0·61 to -0·25), with a higher proportion of children stunted (LAZ score <-2: 35 [10%] of 342 HEU vs 14 [4%] of 342 HU children; odds ratio [OR] 2·67, 95% CI 1·41 to 5·06). Simultaneously, overweight (WLZ score >2) was common in both groups of children at 12 months (54 [16%] of 342 HEU vs 60 [18%] of 340 HU children; OR 0·87, 95% CI 0·58 to 1·31).

Interpretation: Compared with HU children, HEU children have small deficits in early growth trajectories under policies of universal maternal ART and breastfeeding. Large proportions of both HEU and HU children were overweight by 12 months, indicating substantial risks for early onset obesity among South African children. Although the longer-term metabolic effects of ART exposure in the context of childhood obesity warrants further investigation, addressing childhood obesity should be an urgent public health priority in this setting.

Funding: Eunice Kennedy Shriver National Institute of Child Health and Human Development, Elizabeth Glaser Pediatric AIDS Foundation, South African Medical Research Council, and the Fogarty Foundation.