Thyroid Function during Pregnancy

changes in thyroid activity that occur during pregnancy and the proper use of laboratory tests for the diagnosis of thyroid dysfunction in the pregnant patient. Case: A woman in the 18th week of pregnancy pre-sented with tachycardia, increased blood pressure, se-vere vomiting, increased total and free thyroid hormone concentrations, a thyroid-stimulating hormone (TSH) concentration within the reference interval, and an in-creased human chorionic gonadotropin (hCG) b-sub-unit concentration. Issues: During pregnancy, normal thyroid activity un-dergoes significant changes, including a two- to three-fold increase in thyroxine-binding globulin concentra-tions, a 30–100 % increase in total triiodothyronine and thyroxine concentrations, increased serum thyroglobu