Table 1.
Clinical characteristics of individuals with permanent and transient congenital hypothyroidism
| Variable | Permanent CH (n = 360) | n | Transient CH (n = 109) | n | P |
|---|---|---|---|---|---|
| Sex, % | 357 | 109 | |||
| Female | 228 (63.9) | 58 (53.2) | |||
| Male | 129 (36.1) | 51 (46.8) | |||
| Gestational age at birth, wk a | 40.0 (38.0-41.0) | 349 | 39.0 (38.0-40.0) | 109 | .032 |
| Birth weight, kg a | 3.3 (3.0-3.7) | 358 | 3.3 (2.9-3.6) | 109 | .187 |
| Maternal thyroid disease, % | 44 (12.4) | 354 | 27 (24.8) | 109 | < .002 |
| Screening TSH, mIU/L a | 118.9 (39.1-222.1) | 360 | 29.7 (19.8-61.0) | 109 | < .001 |
| Diagnostic TSH a | 100.0 (32.5-300.0) | 355 | 18.4 (12.0-74.6) | 109 | < .001 |
| Diagnostic FT4 value a | 11.2 (6.1-17.3) | 343 | 17.4 (12.7-21.9) | 108 | < .001 |
| Imaging results, % | 311 | 73 | |||
| GIS | 91 (29.3) | 68 (93.2) | |||
| Apparent athyreosis | 77 (24.8) | 5 (6.8) | |||
| Ectopic | 143 (46.0) | 0 (0.0) | |||
| TSH > RI after 6 mo, % | 328 (91.6) | 358 | 20 (18.3) | 109 | < .001 |
| Free T4 < RI after 6 mo, % | 11 (3.1) | 359 | 0 (0.0) | 109 | .064 |
| LT4 dose, μg/kg/d a | |||||
| 6 mo | 4.3 (3.4-5.4) | 354 | 3.3 (2.7-3.7) | 106 | < .001 |
| 1 y | 4.0 (3.2-4.8) | 350 | 2.7 (2.1-3.1) | 107 | < .001 |
| 2 y | 3.8 (3.2-4.5) | 352 | 2.1 (1.6-2.5) | 109 | < .001 |
| 3 y | 3.7 (3.1-4.3) | 337 | 2.0 (1.8-2.4) | 36 | < .001 |
| Maximum LT4 dose, μg/kg/d a | 4.8 (4.0, 5.7) | 360 | 3.3 (2.7-3.7) | 109 | < .001 |
| Increasing LT4 dose requirements, % | 332 (92.2) | 360 | 18 (16.5) | 109 | < .001 |
| LT4 dose ≥ 50 μg/d, % | 275 (76.4) | 360 | 2 (1.8) | 109 | < .001 |
P values from Wilcoxon test (if continuous) or Pearson chi-square test (if categorial).
Abbreviations: GIS, gland in situ; LT4, levothyroxine; RI, reference interval; T4, thyroxine; TSH, thyrotropin.
a Median interquartile range, % = frequency.