Cape Town study links maternal anaemia to smaller infant brain volumes

Brain differences emerged during infancy

A study following mothers and babies in Cape Town has associated anaemia during pregnancy with smaller infant brain volumes, including differences in regions involved in movement, learning and emotional regulation. The research, reported by the Guardian on September 9, tracked more than 300 mother-child pairs and used repeated brain scans from early infancy through the age of two. The findings give policymakers another reason to treat maternal anaemia as a development issue rather than only a short-term pregnancy complication.

Researchers found that total brain volume was, on average, 4% lower among babies born to mothers diagnosed with anaemia than among babies in the comparison group. Differences were also recorded in the putamen, caudate nucleus and corpus callosum. In the corpus callosum, the reported gap grew between 12 and 24 months, indicating that the observed differences did not simply disappear during the first two years of life.

The study was observational, so its results should be understood as a strong association rather than proof that anaemia alone caused every measured difference. The researchers nevertheless reported that the two groups were similar on important household measures, including income and food security. They also connected the brain-imaging results with earlier research in South Africa that found continuing developmental differences among older children exposed to maternal anaemia.

A widespread nutrition challenge

The findings arrive against a difficult global backdrop. The UN Food and Agriculture Organization's 2026 food-security and nutrition report says progress on maternal and child nutrition remains too slow to meet international targets. It identifies worsening anaemia among women aged 15 to 49 across nearly all regions, alongside persistent gaps in dietary diversity and access to healthy food. That institutional evidence supplies global context but does not independently confirm the Cape Town study's new measurements.

Anaemia has multiple possible causes, including iron and other micronutrient deficiencies, infections, inflammation and chronic disease. The Cape Town researchers found higher rates among women living with HIV, underscoring why nutrition programmes may need to operate alongside infection diagnosis and treatment. Screening and interventions therefore have to be adapted to local causes instead of assuming that every case can be addressed with the same supplement.

The research also tested lower-cost portable MRI scanners against conventional hospital machines and found that the portable equipment could detect the same group-level differences. That could matter in places where large scanners are scarce or inaccessible. The next questions are whether the results are reproduced in other populations, how the observed brain differences affect later learning and behaviour, and which combinations of nutrition, antenatal screening and infection management most effectively reduce the risk.