IronNEW2026-10

Pregnancy and iron: Bridging metabolic demands and supplementation needs.

Bedran Michelle, Manceau Hana, Ollivier Helyett, Deleschaux Cécile et al. — Clinical nutrition ESPEN

Summary

During pregnancy, a woman's body needs significantly more iron to support both herself and her developing baby. While iron supplements are crucial for preventing deficiency-related issues like anemia and poor fetal development, this paper highlights the delicate balance required. Both too little and too much iron can lead to health risks, emphasizing the importance of careful management and personalized supplementation strategies.

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Key points

Pregnant women need more iron to support their health and the baby's development.
Not getting enough iron during pregnancy can lead to health problems for both the mother and the baby.
While iron supplements are beneficial for those with low iron, too much iron can also pose risks.
It's important to assess individual iron levels to determine the right approach to supplementation.

What the study looked at

This paper explores the complex needs for iron during pregnancy, examining how the body's demands change and the role of iron supplementation. It also investigates the potential risks associated with both too little and too much iron. As a review paper, this study synthesized existing scientific literature and knowledge on iron metabolism, placental transfer, and the effects of iron status on maternal and fetal health outcomes. It did not involve new experiments or direct participant recruitment but rather analyzed a broad range of previous research. The review found that iron requirements significantly increase during pregnancy, and deficiency can lead to serious issues like maternal anemia, premature birth, and impaired infant development. However, it also highlighted that excessive iron levels can be harmful, potentially contributing to preterm birth and low birthweight. The authors emphasize that supplementation should be carefully managed, ideally based on individual iron status rather than a universal approach, and point out remaining knowledge gaps in optimal dosing and regulation.

Dietary takeaway

For pregnant individuals, it's crucial to discuss iron levels with a healthcare provider to determine if supplementation is needed. While iron-rich foods like lean meats, beans, and fortified cereals are important, relying solely on diet might not be enough to meet increased demands for everyone. Remember that this is one study, and individual needs vary, so always consult your doctor for personalized advice on iron intake during pregnancy.

Abstract

Maternal iron requirements increase during pregnancy. Placental transfer is unidirectional via transferrin receptor 1 and ferroportin, and most fetal iron accumulation occurs in the third trimester. Iron deficiency during pregnancy is associated with maternal fatigue, reduced work capacity, and increased risk of anemia, as well as adverse outcomes such as preterm birth, low birthweight, and impaired neonatal iron stores, which may affect early neurodevelopment. Oral iron supplementation reduces anemia and improves iron status. In women at risk of deficiency, lower prophylactic doses are commonly used. Intravenous iron is effective and generally safe from the second trimester in women who do not respond to or tolerate oral therapy. However, iron status shows a U-shaped association with outcomes: elevated maternal iron has been associated with preterm birth, low birthweight, and possible neurodevelopmental effects. Excess iron may induce oxidative stress and placental iron loading. Hepcidin suppression in the second and third trimesters enhances iron absorption. Important gaps remain regarding hepcidin regulation, placental transport mechanisms, safe upper supplementation limits, and optimal dosing strategies. While supplementation clearly benefits iron-deficient women, current evidence supports screening-based rather than universal supplementation in iron-replete populations. Herein, we discuss the need for iron during pregnancy, the impact of dysmetabolism, and the molecular actors at the cellular and systemic levels to build a translational bridge between clinical unmet needs and fundamental knowledge.

View on PubMed →DOI: 10.1016/j.clnesp.2026.103390