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Hyperthyroidism during pregnancy: Treatment

Douglas S Ross, MD
Section Editors
David S Cooper, MD
Charles J Lockwood, MD, MHCM
Deputy Editor
Jean E Mulder, MD


The treatment of pregnant women with hyperthyroidism parallels that of nonpregnant women but presents unique problems. There are several important issues to be considered when hyperthyroidism occurs during pregnancy. These include understanding indications for treatment, therapeutic options for pregnant women, and goals of antithyroid drug (ATD) therapy.

The treatment of hyperthyroidism during pregnancy is presented here. The clinical manifestations, diagnosis, and causes of hyperthyroidism and other aspects of thyroid disease during pregnancy are discussed separately. (See "Hyperthyroidism during pregnancy: Clinical manifestations, diagnosis, and causes" and "Overview of thyroid disease in pregnancy".)


The Endocrine Society and the American Thyroid Association (ATA) have published clinical guidelines for the management of thyroid dysfunction during pregnancy that are similar to the approach outlined here [1-3]. Treatment recommendations are predominantly based upon observational studies and clinical experience.

Goals — A good fetal and maternal outcome depends upon controlling the mother's hyperthyroidism. There are changes in thyroid physiology during normal pregnancy that are reflected in altered thyroid function tests. Thyroid function tests, therefore, should be interpreted with an understanding of trimester-specific reference ranges for the individual tests. (See "Overview of thyroid disease in pregnancy", section on 'Trimester-specific reference ranges'.)

The goal of treatment is to maintain persistent but mild hyperthyroidism in the mother in an attempt to prevent fetal hypothyroidism [4]. Overtreatment of maternal hyperthyroidism with thionamide antithyroid drugs (ATDs) can cause fetal goiter and primary hypothyroidism. On the other hand, transient central hypothyroidism may be seen in infants whose mothers had poorly controlled hyperthyroidism during pregnancy, presumably due to suppression of the fetal pituitary-thyroid axis [5].

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Literature review current through: Nov 2017. | This topic last updated: Jan 18, 2017.
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