Researchers from the University of Cape Town and King’s College London have suggested that babies born to mothers with anaemia have smaller brains, particularly in key regions linked to movement, learning and the regulation of emotion, reports The Guardian.
They said the differences, first detected at the age of one, could lead to cognitive problems when children started school.
More than a third of pregnant women worldwide have anaemia – typically caused by iron deficiency in which the number of red blood cells in the body is lower than normal. Symptoms include fatigue, shortness of breath and dizziness. Rates are highest in sub-Saharan Africa and south Asia.
The study teams followed more than 300 mothers and their babies in Cape Town, scanning the brains of the infants several times between the ages of three months and two years.
On average, the total brain volume of babies born to anaemic mothers was 4% lower than that of babies born to non-anaemic mothers, despite all of the anaemic mothers being diagnosed only with a mild version of the condition.
Differences were recorded in three specific regions of the brain: the putamen, caudate nucleus and corpus callosum.
“All three of these brain regions are implicated in key neuropsychological functions,” said Jessica Ringshaw, first author and researcher at King’s Institute of Psychiatry, Psychology & Neuroscience (IoPPN) and the University of Cape Town, citing processing speed, emotion regulation and executive function as examples.
Neuropsychologist Ringshaw recently completed her PhD in Paediatric Neuroscience as a Wellcome Trust Fellow at UCT’s Neuroscience Institute.
The gap between the groups of babies widened over the first two years of life – the corpus callosum, for instance, was about 4% smaller at 12 months in the group whose mothers had been anaemic but 6% by 24 months, she said.
Earlier research in South Africa looking at toddlers and school-age children found comparable differences in brain volume.
“These aren’t children who are catching up, where the brain differences are disappearing over time,” added Ringshaw. “They are still there when the children are six-years-old and going to school, and when these things might then start translating into more noticeable cognitive difficulties.”
The findings offer a potential explanation for earlier studies showing that children born to mothers with anaemia scored less well on tests of development.
The mothers with and without anaemia were otherwise very similar in terms of factors such as household income and food security, Ringshaw said, making her confident that maternal anaemia caused the differences the team observed.
The results reinforced the importance of tackling anaemia in women of reproductive age, she noted. “We should be screening for anaemia and iron deficiency, particularly during pregnancy,” she said, recommending the use of oral or even intravenous iron supplementation where appropriate.
The causes of anaemia were complex and could include infectious diseases, with the study finding higher rates of anaemia in HIV+ women, “so having iron interventions, but also appropriate infection management in conjunction with that, is important”.
While the WHO lists reducing rates of anaemia as a priority, progress has stagnated over the past two decades.
“Now more than ever, anaemia needs to be placed at the forefront of public health efforts if we are to ensure that children are not only surviving but thriving,” said Ringshaw.
The research, published in the journal Brain Communications, used special new MRI scanners that are cheaper and more portable than the conventional machines used in hospitals.
It compared images taken using the traditional “high-field” MRI machines with those taken by the portable “low-field” options, and found the latter were sensitive enough to detect the same differences in the brains of babies born to anaemic mothers.
Steve Williams, professor of neuroimaging at King’s, said: “This study has proved that our novel technology can measure the impact of malnutrition on the developing brain, at scale, in some of the most challenging environments. This will provide an early, sensitive assessment of planned interventions.”
Study details
Antenatal maternal anaemia and infant brain structure: high-field (3T) and ultra-low-field (64mT) MRI findings from South Africa
Jessica Ringshaw, Michal Zieff, Niall Bourke et al.
Published in Brain Communications on 8 September 2026
Abstract
With the evolution of ultra-low-field MRI and the recognition of antenatal maternal anaemia as an important driver of altered neurodevelopment in toddlers and children, it is critical to determine whether these effects are detectable at ultra-low-field (64 mT) in infancy. The aim of this study was to assess the impact of antenatal maternal anaemia on infant brain structure across the first 2 years of life, using high-field (3 T) and ultra-low-field (64 mT) MRI. This neuroimaging substudy was embedded within Khula, an observational population-based birth cohort in South Africa. Pregnant women were enrolled antenatally and postnatally. Mother-child dyads (n = 394) were followed prospectively with a subsample attending neuroimaging at ∼3, 6, 12, 18 and 24 months of age. Anaemia was classified using World Health Organization thresholds, and neuroimaging data were processed using MiniMORPH. Linear mixed-effects models were used to investigate associations between antenatal maternal anaemia status and absolute regional infant brain volumes using high-field and ultra-low-field MRI. In repeated measures high-field (n = 195) and ultra-low-field (n = 341) infant neuroimaging subsamples, the prevalence of antenatal maternal anaemia was 28.24% (37/131) and 29.76% (61/205), respectively. Maternal anaemia in pregnancy was associated with altered child brain structure across both MRI systems, with group differences becoming detectable at ∼12 months. In the ultra-low-field subsample, infants born to anaemic mothers had 3.77% smaller intracranial volume (β = −0.24, P = 0.004) and 3.32% smaller putamen volumes (β = −0.18, P = 0.040) across the first 2 years of life. The interaction between antenatal maternal anaemia and age was significant for the caudate nucleus (β = −0.13, P = 0.038) and corpus callosum (β = −0.15, P = 0.007). Antenatal maternal anaemia was associated with 3.70% and 4.29% smaller caudate nucleus volumes at 18 and 24 months of age, respectively. Similarly, infants born to anaemic mothers had 4.39% smaller corpus callosum volumes by 12 months and 6.27% smaller corpus callosum volumes by 24 months. Postnatal child anaemia and antenatal maternal iron deficiency status were not associated with total or regional child brain volumes in the ultra-low-field subsample from this cohort. Maternal anaemia remained a robust predictor of volume differences in sensitivity analyses. This study is the first to demonstrate that the impact of maternal anaemia in pregnancy on child brain structure is detectable as early as infancy. The implications of this research are 2-fold: (i) informing the feasibility of ultra-low-field MRI in low- and middle-income countries and (ii) the timing and optimisation of targeted recommendations for anaemia management in practice and policy.
The Guardian article – Babies born to anaemic mothers have smaller brains, study finds (Open access)
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High iron deficiency prevalence yet 40% of pregnant women don’t get simple screening test