{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T18:49:00Z","timestamp":1783018140369,"version":"3.54.6"},"reference-count":36,"publisher":"SAGE Publications","issue":"12","license":[{"start":{"date-parts":[[2021,12,1]],"date-time":"2021-12-01T00:00:00Z","timestamp":1638316800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Thyroid\u00ae"],"published-print":{"date-parts":[[2021,12]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>Iron deficiency affects thyroid hormone synthesis by impairing the activity of the heme-dependent thyroid peroxidase. The prevalence of iron deficiency is elevated particularly in pregnant women. This study aimed to investigate the effects of iron status on thyroid function in a nationally representative sample of mildly iodine-deficient pregnant women.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>\n                      The study population comprised a sample of pregnant women in Belgium during the first and third trimesters of pregnancy (\n                      <jats:italic toggle=\"yes\">n<\/jats:italic>\n                      \u2009=\u20091241). Women were selected according to a multistage proportional-to-size stratified and clustered sampling design. Urine and blood samples were collected, and a questionnaire was completed face to face with the study nurse. Concentrations of free thyroxine (fT4), total thyroxine (T4), free triiodothyronine, thyrotropin (TSH), thyroglobulin (Tg), thyroid peroxidase antibodies, Tg antibodies, hemoglobin, serum ferritin (SF), soluble transferrin receptor, urinary iodine concentrations (UICs) were measured and body iron stores (BIS) were calculated.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>\n                      Median UICs were 117 and 132\u2009\u03bcg\/L in the first and third trimesters of pregnancy, respectively (\n                      <jats:italic toggle=\"yes\">p<\/jats:italic>\n                      \u2009&lt;\u20090.05). The frequency of SF &lt;15\u2009\u03bcg\/L was 6.2% in the first trimester and 39.6% in the third trimester of pregnancy (\n                      <jats:italic toggle=\"yes\">p<\/jats:italic>\n                      \u2009&lt;\u20090.05). UIC was a significant predictor of serum Tg concentrations (\n                      <jats:italic toggle=\"yes\">p<\/jats:italic>\n                      \u2009&lt;\u20090.01) but not of thyroid hormone or TSH concentrations. The frequency of fT4&lt;percentile 10th in the third trimester of pregnancy was 24% and 14% in pregnant women with negative BIS and positive BIS, respectively (\n                      <jats:italic toggle=\"yes\">p<\/jats:italic>\n                      \u2009&lt;\u20090.05). SF and BIS were significant predictors of fT4 and T4 in the first trimester of pregnancy (\n                      <jats:italic toggle=\"yes\">p<\/jats:italic>\n                      \u2009&lt;\u20090.05). Hemoglobin was a significant predictor of fT4 in both trimesters (\n                      <jats:italic toggle=\"yes\">p<\/jats:italic>\n                      \u2009&lt;\u20090.01) and for T4 in the third trimester (\n                      <jats:italic toggle=\"yes\">p<\/jats:italic>\n                      \u2009=\u20090.015).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion:<\/jats:title>\n                    <jats:p>Iron deficiency, but not mild iodine deficiency, is a determinant of serum fT4 and T4 in pregnant women. Correcting iron deficiency may help to maintain optimal thyroid function, in addition to preventing anemia during pregnancy.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1089\/thy.2021.0286","type":"journal-article","created":{"date-parts":[[2021,9,20]],"date-time":"2021-09-20T03:58:36Z","timestamp":1632110316000},"page":"1868-1877","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":21,"title":["Iron Deficiency Is a Risk Factor for Thyroid Dysfunction During Pregnancy: A Population-Based Study in Belgium"],"prefix":"10.1177","volume":"31","author":[{"given":"Rodrigo","family":"Moreno-Reyes","sequence":"first","affiliation":[{"name":"Department of Nuclear Medicine, Laboratoire Hospitalier Universitaire de Bruxelles (LHUB-ULB); Universit\u00e9 Libre de Bruxelles (ULB), Brussels, Belgium."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bernard","family":"Corvilain","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Laboratoire Hospitalier Universitaire de Bruxelles (LHUB-ULB); Universit\u00e9 Libre de Bruxelles (ULB), Brussels, Belgium."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"Daelemans","sequence":"additional","affiliation":[{"name":"Department of Gynecology and Obstetrics, H\u00f4pital Erasme; Laboratoire Hospitalier Universitaire de Bruxelles (LHUB-ULB); Universit\u00e9 Libre de Bruxelles (ULB), Brussels, Belgium."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fleur","family":"Wolff","sequence":"additional","affiliation":[{"name":"Department of Department of Clinical Chemistry, Laboratoire Hospitalier Universitaire de Bruxelles (LHUB-ULB); Universit\u00e9 Libre de Bruxelles (ULB), Brussels, Belgium."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Camilo","family":"Fuentes Pe\u00f1a","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Laboratoire Hospitalier Universitaire de Bruxelles (LHUB-ULB); Universit\u00e9 Libre de Bruxelles (ULB), Brussels, Belgium."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefanie","family":"Vandevijvere","sequence":"additional","affiliation":[{"name":"Department of Public Health and Surveillance, Sciensano, Brussels, Belgium."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2021,12,16]]},"reference":[{"key":"e_1_3_6_2_2","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2012-3389"},{"key":"e_1_3_6_3_2","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2010-0415"},{"key":"e_1_3_6_4_2","doi-asserted-by":"publisher","DOI":"10.1017\/S0007114512004473"},{"key":"e_1_3_6_5_2","first-page":"258","article-title":"A randomized trial for the treatment of mild iodine deficiency during pregnancy: maternal and neonatal effects","volume":"80","author":"Glinoer D","year":"1995","unstructured":"Glinoer D, , De Nayer P, , Delange F, et al. 1995. A randomized trial for the treatment of mild iodine deficiency during pregnancy: maternal and neonatal effects. 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