{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T00:44:56Z","timestamp":1792111496854,"version":"4.4.0"},"reference-count":28,"publisher":"The Endocrine Society","issue":"11","license":[{"start":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T00:00:00Z","timestamp":1781136000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,10,16]]},"abstract":"Abstract<\/jats:title>\n \n Background<\/jats:title>\n Hemithyroidectomy is increasingly performed in women of reproductive age, but its implications for thyroid function during pregnancy and obstetric outcomes remain unclear.<\/jats:p>\n <\/jats:sec>\n \n Objective<\/jats:title>\n To assess gestational hypothyroidism and the risks of preterm birth and pregnancy loss among pregnancies in women with prior hemithyroidectomy vs matched pregnancies in women without thyroid surgery.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n We conducted a retrospective matched cohort study using anonymized electronic medical records from Maccabi Healthcare Services, Israel, from 2002 to 2023. Pregnancies with at least one thyroid-stimulating hormone (TSH) measurement were included. Pregnancies after hemithyroidectomy were matched to pregnancies without thyroid surgery using exact matching on maternal age, gravidity, and pregnancy year, followed by propensity-score matching on sociodemographic and clinical covariates. Gestational hypothyroidism was defined as TSH &gt;4.0 mIU\/L or levothyroxine initiation during pregnancy and analyzed using generalized estimating equations. Pregnancy loss and preterm birth were analyzed using a weighted time-varying Cox model with gestational age as the time scale, incorporating thyroid status and levothyroxine treatment as time-varying covariates and a hemithyroidectomy-by-trimester interaction.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n The matched cohort included 463 pregnancies after hemithyroidectomy and 2293 matched controls. Prior hemithyroidectomy was associated with higher odds of gestational hypothyroidism (adjusted odds ratio, 4.2; 95% CI, 2.9-6.3; P &lt; .01). In the time-varying outcome analysis, hemithyroidectomy was not associated with increased first-trimester pregnancy loss (hazard ratio [HR], 0.9; 95% CI, 0.7-1.1; P = .29), but was associated with higher hazard of preterm birth or pregnancy loss during the second and third trimesters (HR, 1.6; 95% CI, 1.3-2.0; P &lt; .01).<\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n Prior hemithyroidectomy was associated with gestational hypothyroidism and modestly higher later-gestation hazard of preterm birth or pregnancy loss, supporting enhanced thyroid surveillance during pregnancy.<\/jats:p>\n <\/jats:sec>","DOI":"10.1210\/clinem\/dgag235","type":"journal-article","created":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T11:48:59Z","timestamp":1781178539000},"page":"3042-3049","source":"Crossref","is-referenced-by-count":1,"title":["Gestational hypothyroidism and pregnancy outcomes following hemithyroidectomy: a nationwide matched cohort study"],"prefix":"10.1210","volume":"111","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2640-1924","authenticated-orcid":false,"given":"Dor","family":"Atias","sequence":"first","affiliation":[{"name":"Kahn Sagol Maccabi (KSM) Research & Innovation Center, Maccabi Healthcare Services , Tel Aviv 6801296 ,","place":["Israel"]},{"name":"Gray Faculty of Medical & Health Sciences, Tel Aviv University , Tel Aviv 6139001 ,","place":["Israel"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6639-9219","authenticated-orcid":false,"given":"Raviv","family":"Allon","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology, Head and Neck Surgery, Kaplan Medical Center , Rehovot 76100 ,","place":["Israel"]},{"name":"Faculty of Medicine, Hebrew University of Jerusalem , Jerusalem 9112102 ,","place":["Israel"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nofar","family":"Ben-Basat","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Hebrew University of Jerusalem , Jerusalem 9112102 ,","place":["Israel"]},{"name":"Shamir Medical Center (Assaf Harofeh), Affiliated to Gray Faculty of Medicine, Tel-Aviv University , Tel Aviv 70300 ,","place":["Israel"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5443-5670","authenticated-orcid":false,"given":"Michal","family":"Kovo","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Hebrew University of Jerusalem , Jerusalem 9112102 ,","place":["Israel"]},{"name":"Shamir Medical Center (Assaf Harofeh), Affiliated to Gray Faculty of Medicine, Tel-Aviv University , Tel Aviv 70300 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