The reference value of free triiodothyronine (FT3) in pregnant women is affected by a number of factors, such as reagents and assay methods, and generally ranges between 2.8 and 7.1 pmol/L.
FT3 is an active thyroxine secreted by thyroid follicular epithelial cells, accounting for only about 0.3% of the total, which is not affected by the concentration of binding proteins in the blood circulation, and it can directly reflect the thyroid function, which is more sensitive and specific.
The reference value of FT3 in pregnant women is affected by many factors such as reagents, assay methods, laboratories, etc. The general range is between 2.8 and 7.1 pmol/L. The specific reference value should be based on the normal reference range of the local hospital.
Increased FT3 is more sensitive to hyperthyroidism, early stage or Graves’ disease with precursor of relapse, increased FT3 can also be seen in hyperthyroidism crisis, thyroid hormone insensitivity syndrome, etc. Decreased FT3 can be seen in low T3 syndrome, advanced stage of chronic lymphocytic thyroiditis, application of glucocorticosteroids, etc.
FT3 results during pregnancy should be based on the reference range provided by the hospital, and if the results are abnormal, they should be evaluated by a specialist endocrinologist in combination with other thyroid function indicators.