Table 1.
Thyroid Function Parameters and Urinary Iodine Concentrations in Pregnant Women Negative for TPOAb and/or TgAb Without Overt Thyroid Disease
| First trimester | n | Second trimester | n | Third trimester | n | |
|---|---|---|---|---|---|---|
| Gestational week of samplea,b | 12 (9, 14) | 190 | 20 (17, 23) | 185 | 35 (30, 36) | 178 |
| Iodine concentration (μg/L)a,b | 39.4 (23.3, 84.4) | 190 | 55.4 (32.1, 103) | 186 | 73.2 (44.7, 126.5) | 177 |
| Iodine/creatinine ratio (μg/g)a,b | 104 (66, 172) | 190 | 119 (82, 186) | 186 | 127 (86, 184) | 177 |
| Tg (μg/L)a | 21 (13, 33) | 185 | 19 (12, 30) | 183 | 23 (13, 33) | 179 |
| TSH (mU/L)a | 1.3 (0.1, 4.2) | 190 | 1.8 (0.4, 4.0) | 185 | 2.0 (0.4, 5.4) | 179 |
| fT4 (pmol/L)a | 15.1 (1.8) | 190 | 12.6 (1.4) | 185 | 11.2 (1.4) | 179 |
a
Values are expressed as median (25th, 75th percentile) for iodine concentration, iodine-to-creatinine ratio, and Tg; fT4 values are expressed as mean (SD); TSH and gestational week are expressed as median (min, max).
b
Values differ from reference 13, as women with thyroid dysfunction are excluded here.
TPOAb, thyroid peroxidase antibodies; TgAb, thyroglobulin antibodies; Tg, thyroglobulin; TSH, thyrotropin; fT4, free thyroxine.