Hypoechoic thyroid nodules on ultrasound 4 years after prenatal exposure to radioiodine: resolution with thyroxine therapy

Perry, R.J., Ainine, A., Butler, S. and Donaldson, M.D.C. (2008) Hypoechoic thyroid nodules on ultrasound 4 years after prenatal exposure to radioiodine: resolution with thyroxine therapy. Acta Paediatrica, 97(4), pp. 509-512. (doi: 10.1111/j.1651-2227.2008.00725.x)

Abstract

<p>We describe an infant inadvertently exposed to radioiodine at 17 weeks gestation. His mother had received 400 MBq of ¹³¹I for hyperthyroidism (total T4 178 nmol/L, thyroid stimulating hormone (TSH) <0.1 mU/L, 4-h ¹³¹I uptake 16%). Following cordocentesis at 27 weeks (free T4 12.7 pmol/L, TSH 35.4 mU/L) intra-amniotic thyroxine was withheld and a male infant was born at 39 weeks gestation, birthweight 3520 g. Cord TSH was low (0.1 mU/L), total T4 151 nmol/L on day 4, the mother having received no medication during pregnancy. Postnatal follow-up showed mild TSH elevation (11.0–19.4 mU/L) but normal free T4 (9–12.7 pmol/L) during the first 2 years of life following which the child was discharged still untreated. On recall at 4.3 years, TSH elevation persisted (15.4 mU/L) and ultrasound showed several hypoechoic thyroid nodules within the left lobe that disappeared after thyroxine treatment.</p> <p>Conclusion: In the event of inadvertent exposure to radioiodine in utero, the infant should receive thyroxine therapy from birth in order to protect the thyroid gland from TSH over-stimulation, however mild.</p>

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Donaldson, Dr Malcolm and Perry, Dr Rebecca
• Authors: Perry, R.J., Ainine, A., Butler, S., and Donaldson, M.D.C.
• Subjects: R Medicine > R Medicine (General); R Medicine > RJ Pediatrics
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Clinical Specialities
• Journal Name: Acta Paediatrica
• ISSN: 1651-2227
• Published Online: 07 March 2008