University College Cork (UCC) researchers have called for routine screening for iron deficiency in pregnant women, following new research that shows that iron deficiency in early pregnancy, even without anaemia, may be associated with lower language and motor development scores in children at two years of age.

The findings, published in The Journal of Nutrition, build on major research released last year which showed that four in five pregnant women in Ireland are iron deficient by the third trimester. This new study sheds light on how early in pregnancy this deficiency matters for a baby’s brain development and reinforces the importance of greater awareness, early screening and supporting women throughout pregnancy.

The latest findings are a result of research by the Irish Centre for Maternal and Child Health Research (INFANT) at UCC and partners at the University of Minnesota and the Masonic Institute of the Developing Brain.

This study included 189 mother-child pairs, who participated in the IMPROvED and COMBINE cohort studies at the INFANT Research Centre, UCC.

The key findings:

  • Over 40% of women in the study had low iron stores by mid-pregnancy, despite being a generally healthy, low-risk group.
  • Babies born to mothers who were iron deficient early in pregnancy had lower iron stores at birth, indicating that maternal iron levels directly influence a baby’s iron status.
  • Children were assessed at two years of age, using the Bayley Scales of Infant and Toddler Development, a gold-standard, internationally recognised measure of child neurodevelopment.

The study found that iron deficiency in early pregnancy may be associated with lower motor and language developmental scores at age two.

Why This Matters

Iron is essential for brain development throughout pregnancy, but the critical window appears to be much earlier than previously understood.

Lead researcher Dr Elaine McCarthy, Lecturer in Nutrition at UCC’s School of Food and Nutritional Sciences and Lead Investigator at the INFANT Research Centre, explains:

“We have previously shown that iron deficiency is very common in pregnancy, even in high-resource, low-risk settings like Ireland. This new research provides an early indication of the lasting consequences of iron deficiency without anaemia in pregnancy, further emphasising the importance of adequate iron nutrition during pregnancy to protect the developing infant brain. These findings highlight the need for screening for iron deficiency in women during pregnancy, and trials to look at the benefit of targeted supplementation in women with low iron stores; not just focusing on anaemia in pregnancy.”

Prof Mairead Kiely, Professor of Human Nutrition at UCC adds:

“This data shows that without a diagnosis of anaemia, more than two in five women had low iron stores by mid-pregnancy, which was associated lower language and motor scores in childhood developmental assessments at 2 years.  The widespread malnutrition of iron and other nutrients among women requires attention as malnutrition is intergenerational and has lasting effects which we are only starting to uncover now.”

Dr McCarthy also adds:

“Our aim is to support women. With the right information, dietary guidance and early screening, iron deficiency is something we can address effectively.”

New Free Guide: ‘A Guide on Iron During Pregnancy’

Following last year’s findings, the researchers at UCC and the Ireland South Women & Infants Directorate have developed a free, practical resource ‘A Guide on Iron During Pregnancy’ for expectant parents. Available to download here: https://www.infantcentre.ie/wp-content/uploads/2025/05/UCC-ISWID-A-Guide-on-Iron-During-Pregnancy-Final-PDF.pdf

It includes:

  • Clear information on the importance of iron in pregnancy
  • Practical tips for boosting iron intake
  • Simple, nourishing recipe ideas using accessible foods

Call for Updated Screening Practices

At present, routine screening for iron deficiency is not part of standard antenatal care in Ireland or many other countries, and there is no universally agreed definition for iron deficiency during pregnancy. The research team believes the evidence now strongly supports earlier pregnancy screening for iron deficiency, clearer diagnostic guidelines and greater awareness among healthcare providers and expectant parents.

This study sets the stage for opportunities for larger global collaborative research with the long-term goal of translating findings into policy change and clinical practice worldwide.