Congenital hypothyroidism due to maternal radioactive iodine exposure during pregnancy.
Radioactive iodine (RAI) is used effectively in the treatment of hyperthyroidism and thyroid cancer, but it is contraindicated during pregnancy. RAI treatment during pregnancy can lead to fetal hypothyroidism, mental retardation and increased malignancy risk in the infant. Pregnancy tests must be performed before treatment in all women of reproductive age. However, at times, RAI is being used before ruling out pregnancy.  We herein present a male newborn infant with congenital hypothyroidism whose mother was given a three-week course of methimazole  therapy for her multiple hyperactive nodules and subsequently received 20 mCi RAI during the 12th week of her pregnancy. The patient was referred to our neonatology unit at age two weeks when his thyrotropin (TSH) level was reported to be  high in the neonatal screening test. Physical examination was normal. Laboratory investigations revealed hypothyroidism (free triiodothyronine 1.55 pg/mL, free thyroxine 2.9 pg/mL, TSH 452 mU/L, thyroglobulin 20.1 ng/mL). The thyroid gland could not be visualized by ultrasonography. L-thyroxine treatment was initiated.
Erciyes University Faculty of Medicine, Department of Pediatrics, Division of Neonatology, Kayseri, Turkey.
Selim
S
Kurtoğlu
Mustafa Ali
MA
Akin
Ghaniya
G
Daar
Leyla
L
Akin
Seyma
S
Memur
Levent
L
Korkmaz
Osman
O
Baştuğ
Selcan
S
Yilmaz
D003409:Congenital Hypothyroidism / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007457:Iodine Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000532:radiotherapy; D016606:Thyroid Nodule / Q000532:radiotherapy
D007457:Iodine Radioisotopes