Does in utero exposure to HIV, without infection, affect child development? UCT researchers investigate…

01 Dec 2023 | By Hayley Tomes
01 Dec 2023 | By Hayley Tomes

Our early development defines us. From influencing academic outcomes to socioeconomic factors, there is no escaping the role it plays on our later lives. Understanding factors that affect early child development is critical to improving child outcomes.

While child HIV infection is a known risk factor for neurological outcomes, there has been remarkable success in preventing vertical transmission of HIV and reducing child HIV infection through maternal antiretroviral therapy. However, the antenatal HIV prevalence remains high in many countries and so there is now a growing population of 16 million children who are exposed to HIV in pregnancy but remain uninfected. Over 90% of these children live in sub-Saharan Africa. What remains unclear is the developmental outcomes for children who are HIV-exposed but uninfected in the era of maternal antiretroviral therapy.   

In a landmark systematic review published in the Lancet Child & Adolescent Health, Wedderburn et al (2022) scoured 6 databases and screened 35 527 records from the past two decades. In the end they included 45 articles. They had two aims: 1. To compare the neurodevelopment of HIV-exposed uninfected children with HIV-unexposed children aged 0-5 years; and 2. To analyse the effects of different maternal antiretroviral treatment regimens on the neurodevelopment of HIV-exposed, uninfected children.

The meta-analysis, including eight high quality studies comparing almost 5000 HIV-exposed and unexposed children, found that, on average, children who were HIV-exposed but uninfected had poorer expressive language and gross motor function than HIV-uninfected children by 24 months of age. However, they had similar cognitive development, receptive language development, and fine motor skills, and there was little or no evidence of an effect of specific maternal antiretroviral regimens on neurodevelopment.

The differences in language and motor abilities, despite being clear, are subtle. However, given the numbers of HIV-exposed children who remain free from HIV infection are growing globally, particularly in Africa, even a modest impairment may impact at an individual level and also have a substantial effect at a population level. These findings must be seriously considered and it is important for healthcare workers in areas of high HIV prevalence to be aware of this vulnerable population.

Dr Wedderburn’s work, mentored by Professor Kirsty Donald, has been instrumental in elucidating the impact of antenatal HIV exposure and associated factors on brain outcomes and neurocognitive development, which is critical for child health. She received the best early career oral presentation award at the International workshop on HIV & Pediatrics in Montreal last year. Further work to understand what is causing these differences has been ongoing. In 2023, research using brain magnetic resonance imaging at the Cape University Body Imaging Centre is beginning to reveal neurobiological pathways that may underly the differences in language and motor development that they’re seeing.

Today, on World AIDS Day, we highlight the need to bring communities together and work to ensure that children affected by HIV not only survive, but also thrive. This includes the growing population of children with perinatal HIV exposure who are uninfected but still affected. At the recent fifth International Developmental Paediatrics Associations (IDPA) conference, organised by Professor Donald, the importance of HIV exposure has been highlighted (keynote address by Professor Abubakar). Dr Wedderburn will, furthermore, be speaking on this work at the 2nd International Paediatric HIV Symposium in Africa (IPHASA conference 2023) and the South African Child Health Priorities Association 2023 Conference. Both are virtual and free to register for. Further information on the neurological and neurodevelopmental impact of HIV may be found in a recent book publication edited by Neuroscience Institute members and scientific advisory board members: Jo Wilmshurst, Kirsty Donald, Charles Newton and Amina Abubakar.