title: Thyroid aplasia in male sibling of heterozygotic twins born to the hyperthyroid mother treated with propylthiouracil during pregnancy (case report).
abstract: A 30-year-old pregnant female was diagnosed to have thyrotoxicosis (TSH= 0.005 µU/ml) at 13th week of gestation. Propylthiouracil (PTU; 200 mg daily) was prescribed to her and four weekly follow ups by the endocrinologist and obstetrician were ensured. At each examination TSH, FT4 and FT3 levels were normal and she became symptom free. Repeated ultrasound examination throughout the pregnancy did not reveal any fetal abnormality. The lady normally delivered heterozygotic twins. Umbilical cord blood of the baby boy twin showed a high TSH (541 µU/ml; reference range 0.270 - 4.20 μU/ml). He was started on thyroxine therapy (50 µg once daily). Ultrasound reported the absence of the thyroid gland. One month later TSH was within normal range and thyroxine dose was adjusted to 25 µg once daily. Repeated ultrasound confirmed the absence of thyroid gland. TSH was repeatedly normal. The boy is currently doing well on thyroxine replacement therapy. The other non-identical twin was a healthy girl with normal thyroid function tests and always thereafter. This case report suggested that PTU could be a hazardous drug to the fetus, since the mother gave birth to a baby with thyroid aplasia.
  
  
  BACKGROUND
  PTU, Thyroid aplasia, Thyrotoxicosis, TSH.
authors.affiliation: Department of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia. abdullahmarzouki@yahoo.com
authors.forename: A A
authors.initials: AA
authors.lastname: Almarzouki
mesh_terms: D000328:Adult; D004200:Diseases in Twins / Q000139:chemically induced* / Q000175:diagnosis; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000150:complications / Q000188:drug therapy; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy; D059285:Pregnancy, Twin / Q000187:drug effects; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000175:diagnosis* / Q000188:drug therapy; D011441:Propylthiouracil / Q000009:adverse effects* / Q000627:therapeutic use; D050033:Thyroid Dysgenesis / Q000139:chemically induced* / Q000175:diagnosis*; D014427:Twins
chemical_list: D011441:Propylthiouracil