Infants without HIV suffer no growth check, despite maternal infection

HIV-exposed but uninfected children grew as well as children of HIV-uninfected mothers, no matter how they were fed in the first two years of life in a non-randomised cohort study in KwaZulu Natal, South Africa from 2001-2004, Deven Patel and colleagues reported in a study published in advance online by the journal AIDS.

Exclusive breastfeeding, however, significantly improved the long-term health of children born to HIV-infected mothers, lending further support to the recently revised World Health Organization (WHO) guidelines on infant feeding.

Poor growth and consequently decreased survival is more likely in HIV-infected children. However significantly lower mean birth weight is more frequently observed in children born to HIV-infected mothers compared to children born to uninfected mothers.

Little, however, is known about subsequent growth of HIV-exposed but uninfected children in Africa. Studies in Europe have shown normal patterns of growth in this population, whereas a few studies in Africa have suggested lower growth patterns.

Being undernourished is predictive of death as well as poor early development in low- and middle- income countries where HIV is prevalent.

Infant feeding patterns affect growth; the mean weight of children who are breastfed is greater than most children who are formula-fed during the first half of infancy.

The authors state that no studies have compared growth in exposed but HIV-uninfected children to growth in those born to HIV-uninfected mothers in large African cohorts. Nor, they note, have early life growth patterns by feeding mode been described in detail in this population.

In this non-randomised intervention cohort, children of HIV-infected and uninfected women were weighed and assessed for HIV status from birth until nine months of age on a monthly basis and every three months from 10-24 months of age. Daily infant feeding practices were recorded weekly.

This allowed for detailed and unique analyses of weight gain in children of HIV-infected women compared to infants born to HIV-uninfected women (the reference group) from the same setting.

The HIV prevalence rate among pregnant women in the study area was approximately 40%. High rates of exclusive breastfeeding were achieved with a median duration of breastfeeding of 175 weeks regardless of maternal HIV status.

The objective, the authors stress, was not to describe growth of children in KwaZulu Natal compared to other settings but to determine if maternal HIV infection status and how children are fed make a difference in the long-term growth of children. So the authors deliberately developed their own reference standard rather than using a WHO methodology.

The 1261 children of HIV-infected mothers grew as well as the reference group of 1061 children of HIV-uninfected mothers, regardless of feeding mode.

Exposed and HIV-infected children had weight-for-age scores lower than exposed but HIV-uninfected children (a difference of 420 grammes for male children and 405 grammes for female children at 52 weeks of age)

Of importance in these findings is the fact that HIV-exposed but uninfected children had a growth rate as good as that of the reference group. The authors note this is significant for two reasons:

• Of the approximately 40% of infants born to HIV-infected mothers in Southern Africa most will be exposed but uninfected. While important, the growth and development of these children is often ignored.
• Other studies have shown that in poor rural areas exposed, HIV-uninfected children are at greater risk of death and illness than children born to uninfected mothers. This study was conducted at in seven rural, one semi-urban and one urban primary health care clinic.

Breastfed HIV-infected infants had higher scores for weight for age than those who were not, in particular during the first six weeks of life—a difference of 130 grammes for male children and 110 grammes for female children.

The few HIV-infected women who chose to formula feed were carefully counselled and were in good financial standing and so able to provide replacement feeding in a hygienic way.

Factors affecting infant growth included:

• Mother’s HIV status (lower birth weight in children of HIV-infected mothers)
• Maternal weight (children of larger women were consistently heavier for age from birth than children of smaller women)
• Infants born to HIV-infected mothers with advanced disease (CD4 cell count <200 cells/ml) always weighed less.

These findings support early identification and immediate start of antiretroviral treatment of HIV-infected pregnant women with low CD4 cell counts to improve their virological, immunological and nutritional status and so improve survival and long-term health of themselves and their children.

HIV-infected children, unsurprisingly, weighed less than children exposed but uninfected. The differences continued until the children reached 6-9 months of age and then levelled out.

The authors note European studies show the same differences until children begin antiretroviral treatment, when growth improves. The major challenge is identifying infected children as early as possible and getting them onto treatment as soon as possible after that.

The authors conclude that with “good counselling for appropriate feeding choices and support for optimal feeding practices, HIV-uninfected children of HIV-infected mothers grew as well as those of uninfected women.”

And, in line with recent WHO recommendations, they conclude: “These finding strengthen the recommendations of exclusive breastfeeding for HIV-infected women in resource-poor settings, for long-term child health.”