Table 1.
Characteristics of pregnant women and their offspring by different SCH standards.
| Variables | ET | SCH | P value | P′ value |
|---|---|---|---|---|
| SCH diagnosed by 2011 standards | ||||
| Number | 971 | 585 | ||
| Maternal age (years) | 30 ± 5 | 29 ± 4 | 0.008 | — |
| Prepregnancy BMI (kg/m2)a | 22.58 (18.73–25.39) | 20.57 (17.95–22.59) | <0.001 | <0.001 |
| Number of pregnancies, n (%) | 0.377 | 0.865 | ||
| 1 | 408 (42) | 267 (45.6) | ||
| 2 | 283 (29.2) | 160 (27.4) | ||
| 3+ | 280 (28.8) | 158 (27) | ||
| Number of previous births, n (%) | 0.896 | 0.591 | ||
| 0 | 472 (48.6) | 286 (48.9) | ||
| 1 | 479 (49.3) | 285 (48.7) | ||
| 2+ | 20 (2.1) | 14 (2.4) | ||
| Primiparity, n (%) | 472 (48.6) | 286 (48.9) | 0.915 | 0.401 |
| Gestational age (weeks)a | 38 (36–39) | 39 (37–40) | <0.001 | <0.001 |
| Gestational weight gain (kg) | 12.1 ± 4.1 | 12.0 ± 4.0 | 0.584 | 0.405 |
| Neonatal | ||||
| Male, n (%) | 461 (49.4) | 311 (54) | 0.084 | 0.082 |
| Birth weight (g) | 3,288 ± 459 | 3,275 ± 501 | 0.595 | 0.647 |
| Birth height (cm) | 49.7 ± 2.3 | 49.7 ± 1.4 | 0.761 | 0.789 |
| Apgar scores | 9.9 ± 1.0 | 9.9 ± 0.7 | 0.219 | 0.249 |
| SCH diagnosed by 2017 standards | ||||
| Number | 1,404 | 152 | ||
| Maternal age (years) | 30 ± 4 | 29 ± 4 | 0.119 | — |
| Prepregnancy BMI (kg/m2)a | 21.64 (19.66–24.56) | 20.29 (18.81–22.04) | <0.001 | <0.001 |
| Number of pregnancies, n (%) | 0.571 | 0.790 | ||
| 1 | 603 (42.9) | 72 (47.4) | ||
| 2 | 402 (28.6) | 41 (27) | ||
| 3+ | 399 (28.5) | 39 (25.6) | ||
| Number of previous births, n (%) | 0.961 | 0.824 | ||
| 0 | 685 (48.8) | 73 (48) | ||
| 1 | 688 (49) | 76 (50) | ||
| 2+ | 31 (2.2) | 3 (2) | ||
| Primiparity, n (%) | 685 (48.8) | 73 (48) | 0.858 | 0.470 |
| Gestational age (weeks)a | 39 (36–39) | 39 (38–40) | <0.001 | 0.045 |
| Gestational weight gain (kg) | 12.1 ± 4.1 | 12.0 ± 4.1 | 0.142 | 0.554 |
| Neonatal | ||||
| Male, n (%) | 684 (50.3) | 88 (58.7) | 0.053 | 0.053 |
| Birth weight (g) | 3,292 ± 468 | 3,206 ± 533 | 0.036 | 0.039 |
| Birth height (cm) | 49.7 ± 2.0 | 49.5 ± 2.1 | 0.184 | 0.158 |
| Apgar scores | 9.9 ± 0.9 | 9.9 ± 1.1 | 0.054 | 0.501 |
ET, euthyroidism; SCH, subclinical hypothyroidism.
Continuous variables are expressed as mean ± SD or median with interquartile range, whereas categorical variables are expressed as percentages.
a
Non-normal distribution of continuous variables.
P′value, adjusted for age.