Abstract
To determine second trimester reference intervals for TSH and FT4.
Samples from 3102 subjects were tested for TPO and Tg antibodies.
Elecsys E170 reference intervals for TSH and FT4 were determined using antibody-negative samples.
Second trimester reference intervals for TSH and FT4 were 0.18–4.07 mIU/L and 9.5–15.8 pmol/L, respectively. The Elecsys E170 TSH results were positively biased compared to ARCHITECT
i2000
SR results for these same samples.
Method-specific reference intervals are required for TSH and FT4.