A clinical study coordinated by researchers from Spain, in collaboration with international partners, has shown that administering a single dose of intravenous iron during pregnancy can significantly improve both maternal and neonatal health outcomes. The findings address a frequently overlooked condition — non-anaemic iron deficiency — and suggest that current prenatal screening strategies may require revision.

The trial was led by the University of Granada (UGR) together with the Biomedical Research Networking Centre in Epidemiology and Public Health (CIBERESP), based in Spain, and was conducted in three hospitals in Pakistan, where iron deficiency during pregnancy remains highly prevalent. The results underline the importance of identifying and treating iron depletion before it progresses to full anaemia.

Non-anaemic iron deficiency is characterised by low iron stores, detectable through reduced ferritin levels, despite normal haemoglobin values. Because routine prenatal check-ups often focus solely on haemoglobin measurements, this condition is frequently missed. However, previous research has linked depleted iron reserves to adverse outcomes such as maternal fatigue, impaired quality of life, fetal growth restriction and reduced iron stores in newborns.

The multicentre clinical trial, known as FAIR-TRIAL, enrolled 600 pregnant women over the age of 18 diagnosed with non-anaemic iron deficiency at their first antenatal visit. During the second trimester, researchers assessed whether adding a single intravenous dose of 1,000 mg of iron to the standard daily oral supplementation of 30 mg could improve maternal haemoglobin levels before delivery.

Participants were randomly assigned to two groups: a control group receiving oral iron alone, and an intervention group receiving both oral supplementation and intravenous iron. The results showed that women in the intervention group experienced a mean increase in haemoglobin of 0.74 g/dL compared with the control group. Importantly, no serious or life-threatening adverse events were reported, supporting the safety of the intravenous approach.

The clinical impact was substantial. While 74% of women treated exclusively with oral iron developed anaemia before childbirth, this proportion fell to 23% among those who received intravenous iron. Women in the intervention group also reported lower levels of fatigue, indicating a tangible improvement in well-being during pregnancy.

Benefits extended to neonatal health. Fetal growth restriction affected 11% of babies born to mothers in the control group, compared with just 1% in the intervention group. Newborns whose mothers received intravenous iron also had a higher birth weight and increased iron reserves in umbilical cord blood, factors associated with healthier early development.

Based on these findings, the authors recommend revisiting current antenatal screening protocols. The research team argues that relying exclusively on haemoglobin measurements is insufficient to identify women at risk. Instead, they propose the systematic assessment of ferritin levels at the beginning of pregnancy to enable earlier and more effective intervention.

According to the study’s lead investigator, Khalid Saeed Khan of the University of Granada in Spain, early identification of iron depletion would allow clinicians to apply safe and effective treatments, such as intravenous iron, before complications arise. The study adds to growing evidence that proactive management of micronutrient deficiencies during pregnancy can yield long-term benefits for both mothers and their children.