{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T14:08:12Z","timestamp":1790690892496,"version":"4.1.0"},"reference-count":30,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,11,26]],"date-time":"2021-11-26T00:00:00Z","timestamp":1637884800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012659","name":"Foundation for Innovative Research Groups of the National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["81970682, 81570709"],"award-info":[{"award-number":["81970682, 81570709"]}],"id":[{"id":"10.13039\/501100012659","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2017YFC0907403"],"award-info":[{"award-number":["2017YFC0907403"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100014555","name":"Foundation for Scientific and Technological Development in Health","doi-asserted-by":"publisher","award":["2019416021"],"award-info":[{"award-number":["2019416021"]}],"id":[{"id":"10.13039\/501100014555","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100016807","name":"Natural Science Foundation of Shenyang City","doi-asserted-by":"publisher","award":["17-230-9-02"],"award-info":[{"award-number":["17-230-9-02"]}],"id":[{"id":"10.13039\/100016807","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Hypothyroidism in the first trimester of pregnancy (T1) has great adverse effects on mothers and foetuses. However, few studies have investigated the influence on postpartum thyroid dysfunction. This study aimed to evaluate their long-term effect on postpartum thyroid function within one year after delivery.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>In total, 151 women were recruited from 1496 participants and were classified as newly diagnosed subclinical hypothyroidism (SCH) in T1 (ND-SCH, n=50), previously known SCH before pregnancy (PK-SCH, n=51) and previously known overt hypothyroidism (PK-OH, n=50). Their thyroid functions were dynamically monitored from pre-conception to one-year postpartum.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>During pregnancy, the first thyroid functions\u2019 test time in T1 were 5-8 gestational weeks. After delivery, the prevalence of postpartum thyroiditis (PPT) was comparable in women with previously known and newly diagnosed hypothyroidism [ND-SCH 62.0% <jats:italic>vs<\/jats:italic> PK-SCH 64.7% <jats:italic>vs<\/jats:italic> PK-OH 64.0%, P=0.96]. For the ND-SCH group, PPT was significantly related with thyroid-stimulating hormone (TSH) &amp;gt;4.0 mU\/L occurring at &amp;lt;8 gestational weeks [OR=8.06, 95% CI, 2.08-31.29] and TSH levels outside 1.0-2.5 mU\/L near childbirth [OR=3.73, 95% CI, 1.04-13.41]. For patients with known hypothyroidism before pregnancy (PK-SCH and PK-OH), TSH&amp;gt;2.5 mU\/L in T1 [OR=3.55, 95% CI, 1.43-8.81] and TPOAb\u2265300 \u03bcIU\/mL [OR=6.58, 95% CI, 2.05-21.12] were associated with PPT. Regardless of whether SCH was diagnosed before pregnancy or in T1, the levothyroxine (LT4) treatment was discontinued at delivery. More than 50% of the patients had to face the hypothyroidism phase of postpartum and restarted LT4 treatment in the first-year follow-up. The logistic regression analysis revealed that TSH elevation occurring at &amp;lt;8 gestational weeks [OR=2.48, 95% CI, 1.09-5.6], TSH levels outside 1.0-2.5 mU\/L near childbirth [OR=3.42, 95% CI, 1.45-8.05], and TPOAb\u2265300 \u03bcIU\/mL [OR=6.59, 95% CI, 1.79-24.30] were the risk factors.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>TSH elevation at &amp;lt;8 gestational weeks was associated with PPT after delivery in women with known and newly diagnosed hypothyroidism. Especially for SCH patients who stopped LT4 treatment at delivery, unsatisfactory TSH level at &amp;lt;8 gestational weeks and near childbirth, TPOAb\u2265300 \u03bcIU\/mL were the risk factors for LT4 retreatment in one-year postpartum.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fendo.2021.746329","type":"journal-article","created":{"date-parts":[[2021,12,1]],"date-time":"2021-12-01T07:21:04Z","timestamp":1638343264000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":7,"title":["Postpartum Thyroid Dysfunction in Women With Known and Newly Diagnosed Hypothyroidism in Early Pregnancy"],"prefix":"10.3389","volume":"12","author":[{"given":"Xiaotong","family":"Gao","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xichang","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yutong","family":"Han","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haoyu","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiashu","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuanyuan","family":"Hou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Yang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huiru","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weiping","family":"Teng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhongyan","family":"Shan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2021,11,26]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1097\/01.AOG.0000152345.99421.22","article-title":"Subclinical Hypothyroidism and Pregnancy Outcomes","volume":"105","author":"Casey","year":"2005","journal-title":"Obstet Gynecol"},{"key":"B2","doi-asserted-by":"publisher","first-page":"85","DOI":"10.1097\/AOG.0b013e3181788dd7","article-title":"Maternal Thyroid Hypofunction and Pregnancy Outcome","volume":"112","author":"Cleary-Goldman","year":"2008","journal-title":"Obstet Gynecol"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199908193410801","article-title":"Maternal Thyroid Deficiency During Pregnancy and Subsequent Neuropsychological Development of the Child","volume":"341","author":"Haddow","year":"1999","journal-title":"N Engl J Med"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2265.2009.03743.x","article-title":"Abnormalities of Maternal Thyroid Function During Pregnancy Affect Neuropsychological Development of Their Children at 25-30 Months","volume":"72","author":"Li","year":"2010","journal-title":"Clin Endocrinol (Oxf)"},{"key":"B5","doi-asserted-by":"publisher","first-page":"44","DOI":"10.1089\/thy.2005.15.44","article-title":"Are Detection and Treatment of Thyroid Insufficiency in Pregnancy Feasible","volume":"15","author":"Mandel","year":"2005","journal-title":"Thyroid"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2003-031832","article-title":"Iodothyronine Levels in the Human Developing Brain: Major Regulatory Roles of Iodothyronine Deiodinases in Different Areas","volume":"89","author":"Kester","year":"2004","journal-title":"J Clin Endocrinol Metab"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM198103193041205","article-title":"Thyroid Development and Disorders of Thyroid Function in the Newborn","volume":"304","author":"Fisher","year":"1981","journal-title":"N Engl J Med"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa040079","article-title":"Timing and Magnitude of Increases in Levothyroxine Requirements During Pregnancy in Women With Hypothyroidism","volume":"351","author":"Alexander","year":"2004","journal-title":"N Engl J Med"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1210\/edrv.18.3.0300","article-title":"The Regulation of Thyroid Function in Pregnancy: Pathways of Endocrine Adaptation From Physiology to Pathology","volume":"18","author":"Glinoer","year":"1997","journal-title":"Endocr Rev"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2017-01560","article-title":"Dose Dependency and a Functional Cutoff for TPO-Antibody Positivity During Pregnancy","volume":"103","author":"Korevaar","year":"2018","journal-title":"J Clin Endocrinol Metab"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1089\/thy.2018.0097","article-title":"Different Thyroidal Responses to Human Chorionic Gonadotropin Under Different Thyroid Peroxidase Antibody and\/or Thyroglobulin Antibody Positivity Conditions During the First Half of Pregnancy","volume":"29","author":"Hou","year":"2019","journal-title":"Thyroid"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2014-3704","article-title":"Optimal and Safe Upper Limits of Iodine Intake for Early Pregnancy in Iodine-Sufficient Regions: A Cross-Sectional Study of 7190 Pregnant Women in China","volume":"100","author":"Shi","year":"2015","journal-title":"J Clin Endocrinol Metab"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1089\/thy.2016.0457","article-title":"2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum","volume":"27","author":"Alexander","year":"2017","journal-title":"Thyroid"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.n495","article-title":"Postpartum Thyroiditis","volume":"372","author":"Epp","year":"2021","journal-title":"BMJ"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.3389\/fendo.2020.00220","article-title":"Targeted Antenatal Screening for Predicting Postpartum Thyroiditis and Its Evolution Into Permanent Hypothyroidism","volume":"11","author":"Benvenga","year":"2020","journal-title":"Front Endocrinol (Lausanne)"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1210\/jcem.84.11.6144","article-title":"Postpartum Thyroiditis in Women With Hypothyroidism Antedating Pregnancy","volume":"84","author":"Caixas","year":"1999","journal-title":"J Clin Endocrinol Metab"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1089\/thy.2009.0391","article-title":"Increased Postpartum Thyroxine Replacement in Hashimoto's Thyroiditis","volume":"20","author":"Galofre","year":"2010","journal-title":"Thyroid"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1111\/cen.12604","article-title":"Changes Suggestive of Post-Partum Thyroiditis in Women With Established Hypothyroidism: Incidence and Predictors","volume":"83","author":"Sergi","year":"2015","journal-title":"Clin Endocrinol (Oxf)"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2013-2768","article-title":"Five-Year Follow-Up for Women With Subclinical Hypothyroidism in Pregnancy","volume":"98","author":"Shields","year":"2013","journal-title":"J Clin Endocrinol Metab"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.1089\/thy.2019.0714","article-title":"Postpartum Follow-Up of Patients With Subclinical Hypothyroidism During Pregnancy","volume":"30","author":"Li","year":"2020","journal-title":"Thyroid"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1016\/j.midw.2015.12.006","article-title":"The Effect of Gestational Weight Gain on Likelihood of Referral to Obstetric Care for Women Eligible for Primary, Midwife-Led Care After Antenatal Booking","volume":"34","author":"Daemers","year":"2016","journal-title":"Midwifery"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1007\/s12020-013-9913-2","article-title":"The Pattern of Thyroid Function of Subclinical Hypothyroid Women With Levothyroxine Treatment During Pregnancy","volume":"44","author":"Yu","year":"2013","journal-title":"Endocrine"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1089\/thy.2016.0002","article-title":"Reference Intervals of Thyroid Function During Pregnancy: Self-Sequential Longitudinal Study Versus Cross-Sectional Study","volume":"26","author":"Zhang","year":"2016","journal-title":"Thyroid"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1530\/EJE-10-1041","article-title":"More Than Adequate Iodine Intake may Increase Subclinical Hypothyroidism and Autoimmune Thyroiditis: A Cross-Sectional Study Based on Two Chinese Communities With Different Iodine Intake Levels","volume":"164","author":"Teng","year":"2011","journal-title":"Eur J Endocrinol"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.1097\/01.psy.0000127692.23278.a9","article-title":"What You See May Not be What You Get: A Brief, Nontechnical Introduction to Overfitting in Regression-Type Models","volume":"66","author":"Babyak","year":"2004","journal-title":"Psychosom Med"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1089\/thy.2019.0067","article-title":"Efficacy and Safety of Long-Term Universal Salt Iodization on Thyroid Disorders: Epidemiological Evidence From 31 Provinces of Mainland China","volume":"30","author":"Li","year":"2020","journal-title":"Thyroid"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2011-2576","article-title":"Approach to the Patient With Postpartum Thyroiditis","volume":"97","author":"Stagnaro-Green","year":"2012","journal-title":"J Clin Endocrinol Metab"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1210\/clinem\/dgaa197","article-title":"Postpartum Thyroiditis in Women With Euthyroid and Hypothyroid Hashimoto's Thyroiditis Antedating Pregnancy","volume":"105","author":"Moleti","year":"2020","journal-title":"J Clin Endocrinol Metab"},{"key":"B29","doi-asserted-by":"publisher","DOI":"10.1016\/j.beem.2004.03.010","article-title":"Physiological and Pathological Aspects of the Effect of Human Chorionic Gonadotropin on the Thyroid","volume":"18","author":"Hershman","year":"2004","journal-title":"Best Pract Res Clin Endocrinol Metab"},{"key":"B30","doi-asserted-by":"publisher","DOI":"10.1016\/S2213-8587(13)70086-X","article-title":"Hyperthyroidism in Pregnancy","volume":"1","author":"Cooper","year":"2013","journal-title":"Lancet Diabetes Endocrinol"}],"container-title":["Frontiers in Endocrinology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2021.746329\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,12,1]],"date-time":"2021-12-01T07:21:06Z","timestamp":1638343266000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2021.746329\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,11,26]]},"references-count":30,"alternative-id":["10.3389\/fendo.2021.746329"],"URL":"https:\/\/doi.org\/10.3389\/fendo.2021.746329","relation":{},"ISSN":["1664-2392"],"issn-type":[{"value":"1664-2392","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,11,26]]},"article-number":"746329"}}