Resolution of fetal goiter after discontinuation of propylthiouracil in a pregnant woman with Graves' hyperthyroidism

We report a case of Graves' hyperthyroidism in a 34-year-old pregnant woman treated with propylthiouracil (PTU) complicated by the development of a fetal goiter. Because of the fetal goiter and normal maternal thyroid function tests, the PTU was discontinued. Over the next 10 weeks, there was a progressive decrease in the fetal thyroid volume as documented by ultrasonography. The fetal neck returned to a normal flexed position, fetal growth and amniotic fluid remained normal, and the patient remained asymptomatic. A normal infant was delivered at term. This is the first report to demonstrate that noninvasive management may be appropriate for fetuses with goiter caused by antithyroid drug therapy.