Table 4.
Associations between maternal thyroid hormone levels during pregnancy (27 weeks' gestation) and child neurodevelopment at 6, 12 and 24 months of age.
| Bayley scales | Preschool language scale | ||||||
|---|---|---|---|---|---|---|---|
| Mental development index | Psychomotor development index | Auditory comprehension | Expressive comprehension | Total score | |||
| 6 Months1 | Free T4 | β | −3.14 | −3.27 | −2.03 | 1.65 | −0.10 |
| (95% CI) | (−7.65, 1.36) | (−9.36, 2.82) | (−9.80, 5.75) | (−5.48, 8.79) | (−6.45, 6.25) | ||
| Total T4 | β | 0.03 | −0.06 | −0.24 | 0.58 | 0.19 | |
| (95% CI) | (−0.57, 0.62) | (−0.86, 0.74) | (−1.28, 0.80) | (−0.37, 1.53) | (−0.66, 1.05) | ||
| TSH | β | 0.85 | 1.46 | 1.51 | 0.24 | 1.06 | |
| (95% CI) | (−0.49, 2.18) | (−0.33, 3.26) | (−0.81, 3.84) | (−1.91, 2.38) | (−0.87, 2.98) | ||
|
| |||||||
| 12 Months2 | Free T4 | β | −0.48 | −6.40 | 4.39 | 1.26 | 3.45 |
| (95% CI) | (−6.22, 5.26) | (−13.89, 1.08) | (−3.56, 12.34) | (−7.20, 9.72) | (−4.76, 11.67) | ||
| Total T4 | β | −0.12 | −0.45 | 0.33 | −0.15 | 0.12 | |
| (95% CI) | (−0.92, 0.68) | (−1.53, 0.63) | (−0.79, 1.46) | (−1.34, 1.04) | (−1.05, 1.28) | ||
| TSH | β | 1.71 | 0.10 | 2.92 | 0.46 | 1.91 | |
| (95% CI) | (0.05, 3.37)* | (−2.16, 2.35) | (0.59, 5.25)* | (−2.04, 2.95) | (−0.51, 4.33) | ||
|
| |||||||
| 24 Months3 | Free T4 | β | −4.29 | −2.67 | |||
| (95% CI) | (−11.60, 3.02) | (−8.95, 3.62) | |||||
| Total T4 | β | −0.17 | 0.43 | ||||
| (95% CI) | (−1.20, 0.85) | (−0.43, 1.30) | |||||
| TSH | β | 0.33 | −1.31 | ||||
| (95% CI) | (−1.97, 2.63) | (−3.25, 0.63) | |||||
*P < 0.05.
1Models adjusted for maternal age, employment status at enrollment and at the 6-months visit, country of birth, time lived in the US, Diet Quality Index, blood lead levels and delivery complications; child hospitalization before 6 months, season of assessment and psychometrician.
2Models adjusted for maternal age, employment status at enrollment and at the 6 months visit, country of birth, time lived in the US, Diet Quality Index, Kotelchuck Adequacy of Prenatal Care Utilization Index, blood lead levels, delivery complications and PPVT score; child age, preterm birth, hospitalization at 6 months and 1 year, family structure at 1 year; season, and language spoken at the time of assessment.
3Models adjusted for maternal age, income, employment status at enrollment, 6 months and 1 year, country of birth, Diet Quality Index, Kotelchuck Adequacy of Prenatal Care Utilization Index, blood lead levels, delivery complications, PPVT score; child hospitalization at 1 year; number of children in the home at 6 months, home density at 2 years, family structure at 1 year; season, psychometrician and language of assessment.
4Since TSH was expressed on a log2 basis, β are equal to the change in neurodevelopmental outcomes for a doubling in TSH levels.