Table 2. Repeat serum thyroid test results between 3 and 120 days of age in infants with Down syndrome (n=80).

Thyroid tests	Euthyroid (n=54)	Hypothyroidism needing treatment (n=14)	Compensated hypothyroidism (n=12)
Highest TSH (μIU/ml)
Median (Q1, Q3)	5.65 (3.5, 10.4)	22.2 (11.5, 42.2)	14 (10.7, 17.4)
Minimum, maximum	0.4, 42.9	3.3, 216.5	7.1,41.4
Lowest Total T4 (mcg/dl)
Median (Q1, Q3)	9.6 (4.6, 14.4)	7.2 (1.8, 7.7)	10.5 (10.2, 11.9)
Minimum, maximum	1.4, 17.1	1, 12.3	9.6,12.3
Lowest free T4 (ng/dl)
Median (Q1, Q3)	1.5 (0.9, 1.9)	1.5 (1.3, 1.8)	1.6 (1, 1.9)
Minimum, maximum	0.8, 2.3	1.3, 1.8	1, 1.9