Can too much iron harm pregnancy?

By Ana Espino | Published on February 19, 2026 | 3 min read


Iron-deficiency anemia is one of the most common nutritional disorders during pregnancy, resulting from insufficient iron to support maternal erythropoiesis and fetal development. To prevent it, routine iron supplementation is widely implemented in obstetric protocols. However, this uniform approach has limitations. It overlooks individual variability in iron stores and fails to account for the potentially harmful effects of iron excess, particularly in non-deficient women.

Elevated ferritin levels—reflecting both iron stores and inflammatory status—may be associated with metabolic and vascular complications of pregnancy, such as gestational diabetes, hypertension, and intrauterine growth restriction. These associations remain underexplored in current clinical practice, where ferritin is rarely used as a predictive tool.

One of the key challenges is to better individualize iron intake during pregnancy by identifying women at risk of iron overload. In this context, the present study was initiated to test the hypothesis that elevated maternal ferritin levels are associated with an increased risk of obstetric complications and to evaluate ferritin as a potential risk-stratification biomarker in obstetrics.

High ferritin, high-risk pregnancy ?

A total of 1,561 pregnant women were selected and divided into two groups according to ferritin levels: <40 ng/mL and ≥40 ng/mL, based on previously established data. The researchers compared the frequency of major obstetric complications between the two groups, including gestational diabetes mellitus (GDM), gestational hypertension (GH), preeclampsia, intrauterine growth restriction (IUGR), preterm birth, and amniotic fluid abnormalities.

The results showed a significant increase in several complications among women with ferritin levels ≥40 ng/mL. In particular, significant associations were observed with gestational diabetes, hypertensive disorders, and fetal growth restriction. No notable differences were found regarding amniotic fluid abnormalities or preterm birth. These findings support the hypothesis that elevated maternal ferritin may serve as a marker of metabolic or inflammatory risk rather than simply reflecting adequate iron stores.

Toward smarter supplementation ?

Iron-deficiency anemia is common during pregnancy, yet its standardized treatment does not account for interindividual differences in iron status. A major challenge lies in identifying women with iron excess or underlying inflammation who may be at increased risk of obstetric complications.

This study aimed to evaluate the association between maternal ferritin levels and adverse pregnancy outcomes. The findings suggest that elevated ferritin may be linked to a higher risk of complications, particularly gestational diabetes, preeclampsia, and impaired fetal growth, supporting a more individualized approach to iron supplementation.

However, important limitations remain and warrant further investigation. Future research should include larger-scale cohort studies, improved control for inflammatory confounders, and randomized controlled trials assessing personalized supplementation strategies based on baseline ferritin levels. A better understanding of the interactions among iron metabolism, inflammation, and oxidative stress will also be essential to develop more targeted interventions and improve maternal and neonatal outcomes.

Read next: Vaginal microbiome: a cause of miscarriage ?

About the author – Ana Espino
PhD in Immunology, specialized in Virology  
As a scientific writer, Ana is passionate about bridging the gap between research and real-world impact. With expertise in immunology, virology, oncology, and clinical studies, she makes complex science clear and accessible. Her mission: to accelerate knowledge sharing and empower evidence-based decisions through impactful communication.