Table 2.
The reference ranges for TSH, fT3, and fT4 in consecutive trimesters of pregnancy
| 1st trimester (n = 172) | 2nd trimester (n = 172) | 3rd trimester (n = 152) | |
|---|---|---|---|
| TSH, mIU/L | 0.009 (0.008 – 0.010) | 0.05 (0.01 – 0.11) | 0.11 (0.03 – 0.19) |
| 3.18 (2.96 – 3.83) | 3.44 (3.05 – 3.77) | 3.53 (2.94 – 3.94) | |
| fT3, pmol/L | 3.63 (3.43 – 3.71) | 3.29 (3.16 – 3.41) | 3.10 (2.92 – 3.26) |
| 6.55 (6.23 – 6.84) | 5.45 (5.20 – 5.64) | 5.37 (5.04 – 5.55) | |
| fT4, pmol/L | 11.99 (11.52 – 12.15) | 10.46 (10.34 – 10.67) | 8.96 (8.63 – 9.62) |
| 21.89 (20.84 – 23.92) | 16.67 (16.03 – 17.20) | 17.23 (16.20 – 18.32) | |
Lower and upper limits of the reference intervals (2.5 and 97.5 percentiles) are provided with 90% confidence intervals.