Table 4.

Association between early pregnancy maternal thyrotropin (TSH) and productive vocabulary in the offspring aged 12–36 months (models 5 and 6). The association between maternal TSH and the productive vocabulary is estimated by conditional growth models, including effects of time (offspring age) and main effects of covariates. The outputs of the conditional growth models are reported as odds ratios (OR), standard error (SE), and 95% confidence intervals (95% CI). Numbers represent complete cases included in the analyses. P-values <0.05 are significant and marked in bold.

	Girls (n = 277)				Boys (n = 298)
	OR	SE	95% CI	P	OR	SE	95% CI	P
TSH (≤2.5 vs >2.5 mIU/L)
Intercept	1.00	0.00	1.00; 1.00	<0.001	1.00	0.00	1.00; 1.00	<0.001
Offspring age	9.93	6.26 × 10−3	9.80; 10.05	<0.001	9.35	6.13 × 10−3	9.24; 9.46	<0.001
TSH (>2.5 mIU/L)	1.00	0.08	0.85; 1.17	0.97	0.74	0.09	0.62; 0.88	<0.001
Maternal age	0.89	0.10	0.73; 1.08	0.22	0.77	0.10	0.64; 0.93	0.006
Breastfeeding	1.19	0.08	1.02; 1.40	0.03	1.20	0.08	1.02; 1.42	0.026
Maternal education
Linear	1.18	0.09	0.99; 1.41	0.06	1.02	0.09	0.85; 1.22	0.86
Quadratic	1.11	0.09	0.94; 1.32	0.22	0.87	0.09	0.73; 1.03	0.10
Primi- and multi-parous	0.77	0.10	0.64; 0.93	0.008	0.94	0.09	0.78; 1.13	0.53
Pre-pregnancy BMI
<18.5	0.87	0.10	0.71; 1.06	0.17	1.10	0.09	0.92; 1.31	0.32
>25	1.03	0.09	0.87; 1.22	0.70	0.96	0.09	0.81; 1.14	0.64
Offspring age × TSH (>2.5 mIU/L)	1.06	0.02	1.03; 1.10	<0.001	1.29	0.02	1.24; 1.34	<0.001
TSH (linear)
Intercept	1.00	0.00	1.00; 1.00	<0.001	1.00	0.00	1.00; 1.00	<0.001
Offspring age	9.31	0.00	9.13; 9.50	<0.001	8.49	0.00	8.33; 8.65	<0.001
TSH (linear)	0.87	0.08	0.74; 1.03	0.102	0.65	0.09	0.54; 0.78	<0.001
Maternal age	0.88	0.10	0.73; 1.07	0.207	0.76	0.10	0.63; 0.92	0.005
Breastfeeding	1.19	0.08	1.01; 1.40	0.036	1.20	0.08	1.02; 1.41	0.029
Maternal education
Linear	1.18	0.09	0.99; 1.41	0.067	1.02	0.09	0.85; 1.23	0.825
Quadratic	1.11	0.09	0.94; 1.32	0.220	0.86	0.09	0.73; 1.02	0.090
Primi- and multi-parous	0.77	0.10	0.64; 0.94	0.009	0.93	0.10	0.77; 1.12	0.442
Pre-pregnancy BMI
<18.5	0.87	0.10	0.71; 1.06	0.164	1.09	0.09	0.91; 1.31	0.328
>25	1.03	0.09	0.87; 1.22	0.726	0.96	0.09	0.81; 1.14	0.617
Offspring age × TSH	1.20	0.02	1.15; 1.25	<0.001	1.39	0.02	1.33; 1.45	<0.001

BMI, body mass index; TSH, thyrotropin.