Thyroid functions of neonates with Down syndrome

We aimed to evaluate thyroid functions and volumes and detect abnormalities in 80 neonates with Down syndrome.

Data about free triiodothyronine, free thyroxine, thyroid stimulating hormone, thyroglobulin and urinary iodine levels, and ultrasonographic thyroid volume were collected.

Abnormal thyroid function tests were detected in 53.8% of the patients (n = 50) and these were hyperthyrotropinemia, hypothyroidism, iodine deficiency and iodine overload in 32, 2, 12 and 4 patients, respectively. Thyroid volumes were assessed in 36 patients and a total of 17 abnormalities were detected (7 hypoplasia, 3 agenesis and 7 goiter). In patients with hyperthyrotropinemia mean thyroid volume was significantly greater and mean TSH was significantly higher when compared to the patients without hyperthyrotropinemia.

Neonatal screening by thyroid function tests in Down syndrome should be performed to prevent further intellectual deterioration and improve overall development. In the neonatal period, the risk of hyperthyrotropinemia should be kept in mind.