What is the normal T4 and TSH levels in infants?

Tsh > 40 mU/L. All infants with a low T4 concentration and a TSH concentration greater than 40 mU per L are considered to have congenital hypothyroidism and should have immediate confirmatory serum testing. Replacement levothyroxine (LT4) treatment should be initiated as soon as confirmatory samples have been taken, without waiting for the results.