Evaluation of Thyroid Function during Pregnancy: Have We Taken a Wrong Turn?

Normal pregnancy is associated with profound hormonal and metabolic changes in the mother, including changes in thyroid hormones.  These normal changes include increased thyroid binding globulin, increased total T3 and total T4, transient decrease in TSH, and in some patients, a transient increase in serum FT4 during the first trimester. In 2017, the American Thyroid Association issued new guidelines for the diagnosis and management of thyroid diseases during pregnancy, which can be difficult due to the numerous normal physiological changes.  Most would agree that the document is an excellent review of current literature relating to the assessment of thyroid status during pregnancy.  However, one researcher wonders if a particular recommendation of the document is misguided.