Congenital Hypothyroidism (CH)

In infants with CH, T4 levels are low, which causes the hypothalamus to stimulate TSH production.  However, there is not an increase in T4 to regulate the TSH concentration.  Therefore, the TSH continues to be produced and the levels will elevate dramatically.  The combined clinical manifestation of low T4 levels and high TSH levels are indicative of CH.  Diagnosis and treatment of CH within the first three months of life are crucial to prevent the neurological and mental deficiencies caused by thyroid hormone deprivation.  

Screening Method:

Both a fluoroimmunometric assay for measurement of TSH and time-resolved fluoroimmunoassay for measurement of T4.


Medication to replace thyroid hormones.


1:3,500 births