Table 3 Thyroid function test data of infants with initial and delayed thyroid-stimulating hormone elevations

Initial TFT

Age, HD

8.6 ± 1.1 (7–10)

7.3 ± 2.0 (5–14)

0.15

Corrected age

27.0 ± 1.6 (26^+ 3–30^+ 1)

26.0 ± 1.5 (24^+ 5–29^+ 2)

0.08

T4 (μg/dl)

–

2.4 ± 2.0 (0.2–8.4)

–

fT4 (ng/dl)^a

0.7 ± 0.4 (0.1–1.1)

0.5 ± 0.0 (0.1–1.1)

–

TSH (μIU/ml)

61.0 ± 81.9

3.3 ± 4.0

< 0.001

36.7 (20.2–207.1)^b

2.0 (0.4–17.4)^b

0.001

Delayed TSH elevation

Age, HD

-

36.0 ± 25.2 (11–93)

-

Corrected age

-

30.1 ± 3.9 (25^+ 3–38^+ 1)

-

T4 (μg/dl)

–

2.4 ± 1.4 (0.2–6.5)

–

fT4 (ng/dl)

–

0.7 ± 0.4 (0.02–1.6)

–

TSH (μIU/ml)

–

78.3 ± 138.4

–

35.3 (20.1–667.0)^b

Peak TSH (μIU/ml)

–

88.1 ± 146.7

–

37.3 (20.4–667.0)^b