Table.
Characteristics of the total study population (N=48,145*)
| Maternal characteristics | |
| Age, years | 29·0 (5·1) [N=47,661] |
| Gestational age at the time of sampling, weeks | 12·8 (7·0 to 39·7) [N= 47,979] |
| BMI, kg/m2 | 24·0 (4·4) [N=32,586†] |
| Parity, N (%) | |
| 0 | 24,589 (51·1) |
| 1 | 13,805 (28·7) |
| 2 | 4,400 (9·1) |
| ≥3 | 2,486 (5·2) |
| Missing† | 2,865 (6.0) |
| Smoking status, N (%) | |
| Non/past smoker | 39,788 (82·6) |
| Current smoker | 5,038 (10·5) |
| Missing† | 3,319 (6.9) |
| Education, N (%) | |
| Low | 10,085 (20·9) |
| Medium | 11,122 (23.1) |
| High | 11,744 (24·4) |
| Missing† | 15,194 (31.6) |
| Maternal test results | |
| TSH (mU/L) | 1·32 (0·13–4·50) [N=47,524] |
| FT4 (pmol/L) | 13·0 (7·3–21·9) [N=47,394] |
| TPOAb positivity, N (%) | 3,128 (7·5) [N=41,706] |
| TgAb positivity, N (%) | 1,063 (5·8) [N=18,355] |
| Child characteristics | |
| Birth weight, grams | 3,400 (536) |
| Small for gestational age, N (%) | 4,771 (9·9) |
| Large for gestational age, N (%) | 4,736 (9·8) |
| Gestational age at birth, weeks | 39·9 (35·5–42·0) |
| Sex, N (%) | [N=37,181] |
| Female | 19,644 (40.8) |
| Male | 19,054 (39.6) |
| Missing† | 9,447 (19.6) |
Table shows descriptive statistics of the characteristics of all included women as the mean (SD), median (95% range) or count (percentage), as appropriate. Cohort-specific descriptive characteristics are shown in appendix p10–13.
*
Number of participants with available data on either of thyroid function tests, unless otherwise indicated.
†
Missing mostly due to lack of data from one or some cohorts.
For detailed description of missing data of covariates per cohort see appendix p14.