Trimester

Number

Urinary iodine concentration (μg/L)

Urinary iodine concentration distribution

Median

Range

<150 μg/L

≥150 μg/L

1^st

19

110

5 - 255

13 (68.4%)

6 (31.6%)

2^nd

83

105

5 - 245

61 (73.5%)

22 (26.5%)

3^rd

42

90

5 - 295

32 (76.2%)

10 (23.8%)

P-value = 0.4