There are seven items of thyroid function (how to read a thyroid function test), but not all of them need to be checked during pregnancy. Because thyroid binding globulin is elevated during pregnancy, TT4 and TT3 are also elevated during pregnancy, so don’t think you have hyperthyroidism if you find TT4 and TT3 elevated during pregnancy! It is also not recommended to check TT4 and TT3 during pregnancy. For pregnant women without previous hyperthyroidism, the indicators that need to be checked during pregnancy include FT4, FT3, TSH and TPOAb, which generally range from 0.1-2.5mIU/L in early pregnancy, 0.2-3.0mIU/L in mid-pregnancy (12-28 weeks) and 0.3-3.0mIU/L in late pregnancy (after 28 weeks). For pregnant women with pre-pregnancy hyperthyroidism, the indicators that need to be checked during pregnancy include FT4, FT3, TSH, TRAb and TPOAb. The dose of antithyroid drugs is adjusted according to FT4, FT3 and TSH during pregnancy, and the control target is FT4 close to or mildly above the upper reference value.