TY - JOUR
T1 - Antithyroid drug treatment in pregnancy
T2 - A first report from the Danish PRETHYR multicenter study
AU - Uldall-Torp, Nanna Maria
AU - Pedersen, Inge Bülow
AU - Carlé, Allan
AU - Karmisholt, Jesper Scott
AU - Ebbehøj, Eva
AU - Grove-Laugesen, Diana
AU - Brix, Thomas Heiberg
AU - Bonnema, Steen Joop
AU - Schrijvers, Bieke F
AU - Nygaard, Birte
AU - Sigurd, Lena Bjergved
AU - Feldt-Rasmussen, Ulla
AU - Klose, Marianne
AU - Rasmussen, Åse Krogh
AU - Andersen, Stig
AU - Andersen, Stine Linding
N1 - © The Author(s) 2026. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For commercial re-use, please contact [email protected] for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact [email protected]. See the journal About page for additional terms.
PY - 2026/3/6
Y1 - 2026/3/6
N2 - CONTEXT: Hyperthyroidism caused by Graves' disease (GD) should be treated in pregnancy to prevent maternal and fetal complications, however, side effects observed with antithyroid drugs (ATDs) may complicate current clinical management.OBJECTIVE: To investigate current treatment practices for hyperthyroidism during pregnancy in Denmark and the characteristics of women receiving ATDs.METHODS: The Danish multicenter study PRETHYR (Pregnancy Investigations on Thyroid Disease) included women with GD and women treated with ATDs in pregnancy. Maternal characteristics, pre-conception measurements of thyroid stimulating hormone (TSH), total triiodothyronine (TT3), and TSH-receptor antibodies (TRAb), and information on the clinical management and treatment before and during pregnancy, were obtained through patient questionnaires and review of the medical record.RESULTS: Of the 121 women included, 97.5% had GD. Among the 102 women with known thyroid disease preconceptionally and no prior definitive treatment, 58.8% (n = 60) received ATDs in pregnancy. These women were more often managed by endocrinologist at conception, had lower preconception TSH and higher TT3 and TRAb compared to women not treated with ATDs. Treatment was predominantly confined to the first half of the first trimester and generally discontinued by the second or third trimester. Prior to conception, 59.1% of women treated with methimazole (MMI) were switched to propylthiouracil (PTU), and 10.7% were switched from PTU to MMI.CONCLUSIONS: This is the first report from a multicenter study on pregnant women with GD and women treated with ATDs during pregnancy. The results provide insight into the current clinical treatment practices of hyperthyroidism in Denmark.
AB - CONTEXT: Hyperthyroidism caused by Graves' disease (GD) should be treated in pregnancy to prevent maternal and fetal complications, however, side effects observed with antithyroid drugs (ATDs) may complicate current clinical management.OBJECTIVE: To investigate current treatment practices for hyperthyroidism during pregnancy in Denmark and the characteristics of women receiving ATDs.METHODS: The Danish multicenter study PRETHYR (Pregnancy Investigations on Thyroid Disease) included women with GD and women treated with ATDs in pregnancy. Maternal characteristics, pre-conception measurements of thyroid stimulating hormone (TSH), total triiodothyronine (TT3), and TSH-receptor antibodies (TRAb), and information on the clinical management and treatment before and during pregnancy, were obtained through patient questionnaires and review of the medical record.RESULTS: Of the 121 women included, 97.5% had GD. Among the 102 women with known thyroid disease preconceptionally and no prior definitive treatment, 58.8% (n = 60) received ATDs in pregnancy. These women were more often managed by endocrinologist at conception, had lower preconception TSH and higher TT3 and TRAb compared to women not treated with ATDs. Treatment was predominantly confined to the first half of the first trimester and generally discontinued by the second or third trimester. Prior to conception, 59.1% of women treated with methimazole (MMI) were switched to propylthiouracil (PTU), and 10.7% were switched from PTU to MMI.CONCLUSIONS: This is the first report from a multicenter study on pregnant women with GD and women treated with ATDs during pregnancy. The results provide insight into the current clinical treatment practices of hyperthyroidism in Denmark.
U2 - 10.1210/clinem/dgag099
DO - 10.1210/clinem/dgag099
M3 - Journal article
C2 - 41790746
SN - 0021-972X
JO - The Journal of clinical endocrinology and metabolism
JF - The Journal of clinical endocrinology and metabolism
ER -