| Gestation (weeks) | Age of infant | Free T4 (ng/dL) | T4 (mcg/dL) | T3 (ng/dL) | TSH (mU/L) |
| 23 to 27 weeks | Cord | 1.28±0.4 | 5.4±2.0 | 20±15 | 6.8±2.9 |
| 7 days | 1.47±0.6 | 4.0±1.8 | 33±20 | 3.5±2.6 | |
| 14 days | 1.45±0.5 | 4.7±2.6 | 41±25 | 3.9±2.7 | |
| 28 days | 1.50±0.4 | 6.1±2.3 | 63±27 | 3.8±4.7 | |
| 28 to 30 weeks | Cord | 1.45±0.4 | 6.3±2.0 | 29±21 | 7.0±3.7 |
| 7 days | 1.82±0.7 | 6.3±2.1 | 56±24 | 3.6±2.5 | |
| 14 days | 1.65±0.4 | 6.6±2.3 | 72±28 | 4.9±11.2 | |
| 28 days | 1.71±0.4 | 7.5±2.3 | 87±31 | 3.6±2.5 | |
| 31 to 34 weeks | Cord | 1.49±0.3 | 7.6±2.3 | 35±23 | 7.9±5.2 |
| 7 days | 2.14±0.6 | 9.4±3.4 | 92±36 | 3.6±4.8 | |
| 14 days | 1.98±0.4 | 9.1±3.6 | 110±41 | 3.8±9.3 | |
| 28 days | 1.88±0.5 | 8.9±3.0 | 120±40 | 3.5±3.4 | |
| ≥37 weeks | Cord | 1.41±0.3 | 9.2±1.9 | 60±35 | 6.7±4.8 |
| 7 days | 2.70±0.6 | 12.7±2.9 | 148±50 | 2.6±1.8 | |
| 14 days | 2.03±0.3 | 10.7±1.4 | 167±31 | 2.5±2.0 | |
| 28 days | 1.65±0.3 | 9.7±2.2 | 176±32 | 1.8±0.9 |
