Supplementary Table 1 Age-specific reference values for thyroid hormone and thyroxine-binding globulin levels in neonates published by Lem et al.24

Age / -2 SDS / -1 SDS / 0 SDS / +1 SDS / +2 SDS
FT4 (pmol/L) / Day of birth / 12.12 / 15.81 / 21.78 / 32.65 / 56.54
1 day-7 days / 12.32 / 15.91 / 21.61 / 31.65 / 52.54
8 days-1 month / 12.81 / 16.12 / 21.12 / 29.28 / 44.33
TT4 (nmol/L) / Day of birth / 75.26 / 99.44 / 132.38 / 177.64 / 240.37
1 day-7 days / 75.90 / 99.96 / 132.64 / 177.36 / 239.10
8 days-1 month / 77.93 / 101.62 / 133.44 / 176.47 / 235.16
TT3 (nmol/L) / Day of birth / 0.30 / 1.23 / 2.18 / 3.13 / 4.09
1 day-7 days / 0.32 / 1.25 / 2.18 / 3.13 / 4.08
8 days-1 month / 0.39 / 1.29 / 2.21 / 3.13 / 4.06
rT3 (nmol/L) / Day of birth / 0.30 / 0.48 / 0.87 / 1.88 / 5.51
1 day-7 days / 0.30 / 0.48 / 0.86 / 1.82 / 5.20
8 days-1 month / 0.30 / 0.47 / 0.83 / 1.67 / 4.36
TSH (mU/L) / Day of birth / 2.43 / 3.84 / 6.44 / 11.75 / 24.03
1 day / 1.90 / 3.21 / 5.54 / 9.76 / 17.58
2 days / 1.40 / 2.61 / 4.64 / 7.94 / 13.10
3 days / 0.94 / 2.03 / 3.75 / 6.24 / 9.65
4 days / 0.60 / 1.48 / 2.85 / 4.63 / 6.82
5 days-7 days / 0.58 / 1.18 / 2.14 / 3.57 / 5.58
8 days-1 month / 0.58 / 1.18 / 2.14 / 3.57 / 5.57
TBG (mg/L) / Day of birth / 19.17 / 23.34 / 28.68 / 35.61 / 44.70
1 day-7 days / 19.16 / 23.34 / 28.67 / 35.59 / 44.68
8 days-1 month / 19.12 / 23.28 / 28.61 / 35.51 / 44.59

24. Lem AJ, de Rijke YB, van Toor H, de Ridder MA, Visser TJ, Hokken-Koelega AC. Serum thyroid hormone levels in healthy children from birth to adulthood and in short children born small for gestational age. J Clin Endocrinol Metab. 2012; 97: 3170-3178.

FT4: free thyroxine; TT4: total thyroxine;TT3: total triiodothyronine; rT3: reverse triiodothyronine; TBG: thyroxine-binding globulin; TSH: thyrotropin.