Losses of children’s cognitive potential over time: A South African example

About 250 million children under the age of 5 years in low-and middle-income countries (LMICs) lose lifelong cognitive potential. However, the primary focus of interventions has been to increase survival and promote growth. All pregnant women in 24 non-contiguous, low-income areas in Cape Town, South Africa (N=1 238) were recruited between 2009 and 2010 and reassessed six times over 8 years post birth. Mothers in half of the 24 areas were randomised to receive home visits by community health workers, concentrated during the pregnancy and the first 6 months of life. At 18 months, the children’s cognitive development was at the global norm, i.e a mean standard deviation (SD) value of 100 (15). By 5 years of age, the mean cognitive development fell to one SD below the global norm (<85; mean = 83) and 60% of children had scores below the global mean. By 8 years of age, cognitive development scores significantly fell again (mean = 73; 88% of children <85). The magnitude of the loss was substantial and warrants sustained interventions throughout childhood that support children’s cognitive development in LMICs. The first 1 000 days of life are important, but insufficient to inoculate children against the negative consequences of poverty and coping with multiple, chronic community challenges (e.g. HIV, alcohol abuse, interpersonal violence).