Table 3.

Trimester-specific associations between three thyroid markers and glucose metabolism indicators by GEE.

Variables	Fasting glucose		Glucose at 1 h		Glucose at 2 h		GDM
	β (95% CI)	P	β (95% CI)	P	β (95% CI)	P	OR (95% CI)	P
T3
First trimester	−0.03 (−0.07, 0.06)	0.10	0.22 (0.10, 0.35)	<0.001	0.07 (−0.02, 0.17)	0.15	1.67 (1.33, 2.10)	<0.001
Second trimester	0.16 (0.11, 0.20)	<0.001	0.41 (0.28, 0.55)	<0.001	0.21 (0.11, 0.31)	<0.001	2.50 (1.95, 3.21)	<0.001
Third trimester	0.13 (0.10, 0.16)	< 0.001
fT4
First trimester	0.01 (0.006, 0.02)	<0.001	−0.03 (−0.05, −0.01)	0.001	−0.03 (−0.05, −0.01)	0.001	1.00 (0.95, 1.04)	0.84
Second trimester	−0.02 (−0.03, −0.01)	0.003	−0.14 (−0.18, −0.10)	<0.001	−0.08 (−0.11, −0.05)	<0.001	0.89 (0.82, 0.96)	<0.001
Third trimester	−0.005 (−0.01, 0.004)	0.29
T3/fT4
First trimester	−0.01 (−0.02, −0.01)	0.01	0.04 (0.02, 0.06)	<0.001	0.02 (0.01, 0.04)	<0.001	1.08 (1.04, 1.12)	<0.001
Second trimester	0.02 (0.01, 0.02)	<0.001	0.05 (0.04, 0.06)	<0.001	0.03 (0.02, 0.04)	<0.001	1.09 (1.07, 1.12)	<0.001
Third trimester	0.01 (0.01, 0.02)	<0.001
TSH
First trimester	−0.01 (−0.01, 0.00)	0.21	0.04 (0.01, 0.07)	0.01	0.05 (0.03, 0.08)	<0.001	1.03 (0.99, 1.08)	0.13
Second trimester	−0.01 (−0.02, 0.01)	0.33	−0.09 (−0.13, −0.05)	<0.01	−0.04 (−0.07, −0.01)	<0.001	0.91 (0.83, 0.99)	0.03
Third trimester	−0.01 (−0.002, 0.01)	0.16

β and OR were adjusted for age, pre-pregnancy BMI, sampling seasonality, family diabetes history, parity, smoking in early pregnancy, drinking status, gestational weeks, education, income, and residence. β and OR indicated the effect size of per nmol/L, per pmol/L, per 10 unit and per μIU/mL for T3, fT4, T3/fT4 and TSH, respectively. Boldface indicates statistically significant.

OR, odds ratio.