Data on 15 infants referred with elevated capillary TSH in whom capillary TSH was <40 mU/L and venous fT4 was <10 pmol/L
| Patient no. | BW (kg) | GA (weeks) | Sick? (Y/N) | cTSH (mU/L) (age in days) | vTSH (mIU/L) (age in days) | vfT4 (pmol/L) | Comment | First cTSH (mU/L) (age in days) | Other cTSH (mU/L) (age in days) |
|---|---|---|---|---|---|---|---|---|---|
| True congenital hypothyroidism | |||||||||
| 1 | 2.95 | 39 | N | 9.5* (12) | 22.7 (18) | 4.8 | Probable dyshormonogenesis on radio-isotope scan | 23.2 (5) | |
| 2 | 4.22 | 42 | N | 21.8* (17) | 49.9 (20) | 8.0 | Confirmed CH (rising TSH on diagnostic challenge) but no imaging performed | 9.42 (5) | |
| 3 | 3.54 | 39 | N | 25.7 (6) | 55.0 (15) | 9.0 | Dyshormonogenesis (no mutation found) | ||
| 4 | 2.8 | 40 | N | 26.4* (18) | N/A (22) | 7.1 | Dyshormonogenesis; IUGR | 15.3 (6) | |
| 5 | 3.08 | 38 | N | 14.3* (15) | 52.45 (24) | 6.6 | Confirmed CH but cause unknown (no uptake on RIS but on L-T4 for > 4 weeks prior to imaging) | 13.7 (6) | |
| 6 | 3.52 | 40 | N | 34.9* (14) | >100 (16) | 6.0 | Dyshormonogenesis (confirmed TPO defect) | 10.16 (5) | |
| 7 | 1.66 | 28 | Y | 32.3 (4) | 27.0 (9) | 7.5 | Respiratory distress syndrome with small IVH in perinatal period). Confirmed CH (TSH 15.9 mU/L after >1 year on L-T4 therapy) | ||
| Status uncertain | |||||||||
| 8 | 3.5 | 39 | Y | 15.0† (25) | 11.2 (29) | 6.6 | Interrupted aortic arch and Di George (died aged 3 months) | 10 (6) | 20 (16) |
| 9 | 1.04 | 29 | Y | 21.0* (15) | 41.8 (17) | 7.2 | Down syndrome with AVSD and chronic lung disease (died aged 6 months) | 7.4 (6) | 75 (23) NB after vTFTs |
| 10 | 1.49 | 31 | N | 21.0* (10) | 150 (15) | <5.0 | PDA (resolved). No imaging performed. Still on L-T4 | 5.77 (5) | 48.4 (17) NB after vTFTs |
| Transient TSH elevation | |||||||||
| 11 | 3.83 | 40 | N | 27.0* (27) | N/A (36) | 9.7 | No imaging; treatment never started | 16 (4) | |
| 12 | 2.9 | 37 | Y | 15.0* (18) | 110 (24) | 4.8 | ECMO for Group B Streptococcus sepsis | 14 (14) | |
| 13 | 3.65 | 37 | N | 33.0* (18) | 75.0 (22) | 9.8 | PAX8 mutation and thyrotropin receptor polymorphism | 9 (6) | |
| 14 | 3.01 | 37 | Y | 9.8 (10) | 73.5 (17) | 5.1 | Renal and lung dysplasia, imperforate anus | 182.03 (39) NB after vTFTs | |
| 15 | 1.01 | 27 | Y | 11.2† (28) | 17.9 (36) | 9.4 | Preterm/VLBW | 1.49 (5) at 28 weeks GA | 11.8 (25) |
*Repeat sample.†Second repeat sample.
AVSD, atrioventricular septal defect; BW, birthweight; CH, congenital hypothyroidism; cTSH, capillary thyroid-stimulating hormone; ECMO, extra-corporeal membrane oxygenation; fT4, free thyroxine; GA, gestational age; IUGR, intrauterine growth restriction; IVH, intraventricular haemorrhage; L-T4, levo-thyroxine; N/A, not available; NB, nota bene; PDA, patent ductus arteriosus; TPO, thyroperoxidase; TSH, thyroid-stimulating hormone; vfT4, venous free thyroxine; VLBW, very low birth weight; vTFT, venous thyroid function test.