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Published on: May 10, 2022
Iron deficiency predicts poor maternal thyroid status during pregnancy
Michael B Zimmermann1, Hans Burgi, Richard F Hurrell
1Laboratory for Human Nutrition, Swiss Federal Institute of Technology (Eidgenössische Technische Hochschule) Zürich, Schmelzbergstrasse 7, LFV E 19, CH-8092 Zürich, Switzerland. michael.zimmermann@ilw.agrl.ethz.ch
The Journal of Clinical Endocrinology and Metabolism
|June 15, 2007
Summary
Poor maternal iron status during pregnancy is linked to altered thyroid function. This may impact fetal development, highlighting the importance of iron for expectant mothers.
Area of Science:
- Obstetrics and Gynecology
- Endocrinology
- Nutritional Science
Background:
- Iron deficiency is prevalent in pregnant women, potentially affecting thyroid metabolism.
- Impaired maternal thyroid function can lead to neurodevelopmental issues in offspring.
Purpose of the Study:
- To determine if maternal iron status influences thyroid-stimulating hormone (TSH) and total thyroxine (TT4) levels during pregnancy.
Main Methods:
- A national sample of 365 pregnant Swiss women (second/third trimester) provided blood and urine samples.
- Measured: TSH, TT4, hemoglobin, ferritin, transferrin receptor, and urinary iodine.
- Calculated body iron stores and used stepwise regression for associations.
Main Results:
- Nearly 40% of women had negative iron stores; 16% had low TT4, and 6% had high TSH.
- Negative iron stores significantly increased the risk of low TT4 (RR 7.8).
- Iron status markers (ferritin, transferrin receptor, body iron) strongly predicted TSH and TT4 (P < 0.0001).
Conclusions:
- Poor maternal iron status is a significant predictor of elevated TSH and reduced TT4 in pregnancy.
- Findings are relevant for areas with borderline iodine deficiency.
- Emphasizes the critical role of iron in maintaining maternal thyroid health during gestation.
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