To determine the means, medians and reference intervals for TSH (thyroid-stimulating hormone) and fT4 (free thyroxine) for each month of gestation and for three trimesters in Korean pregnant women.
METHODS:
Serum samples were collected from 265 pregnant women with singleton gestation. Levels of TSH, fT4 were measured by immunoassay. After exclusion of subjects with positive antimicrosomal autoantibodies, the means, medians and reference intervals based on 2.5th and 97.5th percentiles for TSH, fT4 were determined.