The association of hyperthyroidism and pregnancy is a rare but potentially serious condition that occurs in 0.2% of pregnancies (1). However, during pregnancy, hyperthyroidism is frequently seen as a maternal endocrine disease; Graves' disease is the most frequent one in etiology (1-2). Maternal Graves' disease and the antithyroid drugs used to treat hyperthyroidism in pregnant women can affect fetus causing hyperthyroidism or hypothyroidism and goiter (3). Fetal hypothyroidism may be caused by transplacental passage of either maternal thyrotropic-binding inhibitory immunglobulin antibodies or maternal treatment with antithyroid drugs during pregnancy (4). Congenital hypothyroidism is seen in 1 in every 3500 neonates (5-6). We present a case of fetal goiter caused by maternal usage of propylthiouracil during pregnancy that was diagnosed on a prenatal ultrasonography.
Keywords: Fetal goiter, neonatal hypothyroidism