A mouse study suggests that iron deficiency before and during pregnancy can leave persistent changes in brain minerals and gene activity even after blood iron levels are restored at birth.
A study from the University of Rochester has added to evidence that iron shortages in pregnancy may have consequences that extend well beyond birth. Researchers reported that when mice were deprived of iron before and during gestation, the offspring showed lasting changes in brain development even after their blood iron levels were restored at birth. The findings, published in The Journal of Nutrition, suggest that a normal blood test may not always reflect what is happening in the brain.
Margot Mayer-Proschel, a professor of Biomedical Genetics and Neuroscience at the University of Rochester School of Medicine and Dentistry, said pregnancy is a crucial period for iron-dependent brain development and that current clinical measures may underestimate the long-term effects of deficiency. In the experiment, mice were fed iron-sufficient or iron-deficient diets before conception and throughout pregnancy. After birth, all of the animals were switched to iron-sufficient diets, yet the researchers still found disruptions in brain iron levels, with some areas remaining depleted and others showing excess accumulation.
The study also found broader mineral imbalances in the brain, including changes in calcium, magnesium, manganese, copper and zinc. These shifts were more pronounced in the brain than in the blood, leading the researchers to conclude that blood tests alone may miss important developmental damage. They also reported changes in gene activity linked to brain development, communication between nerve cells and myelin, the protective coating that helps electrical signals travel efficiently along nerve fibres.
Several of the strongest changes appeared in the superior colliculus, a region involved in processing sensory information and directing attention. That matters because earlier human studies have linked low maternal iron in early pregnancy with a higher risk of later cognitive and developmental difficulties, including autism, attention deficit hyperactivity disorder and learning problems. A 2025 systematic review also found that prenatal iron deficiency is associated with a range of neurodevelopmental concerns, although another review in 2024 said the benefits of iron supplementation for child neurodevelopment in higher-income countries remain unclear and need further study. Taken together, the research points to the same basic message: iron is a small nutrient with an outsized role in early brain development, and deficiency during pregnancy may have consequences that are not quickly reversed.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
