Table 1.

Thyroid function parameters and urinary iodine.

Time	First Trimester	Second Trimester	Third Trimester	Postpartum
N	427	268	355	25
TSH (μIU/mL)	1.56 ± 1.21 *	1.77 ± 0.98	1.77 ± 0.87 *	1.31 ± 0.98
FT4 (ng/dL)	1.31 ± 0.49	1.22 ± 0.59	1.22 ± 0.63	1.26 ± 0.33
FT4 (pmol/L)	16.86 ± 6.31	15.70 ± 7.59	15.70 ± 8.10	16.22 ± 4.25
Percentage positive anti-TPO (U/mL)	8%	6%	3% **	12%
TFQI	−0.056 ± 0.338	−0.060 ± 0.398	−0.059 ± 0.408	−0.053 ± 0.252
Urinary iodine (μg/L)	133 ± 68	137 ± 71	137 ± 65	165 ± 69

* ANOVA—Tukey/Kramer post hoc test p: 0.005, ** Chi Square p: 0.030.