There are many causes of high thyroid stimulating hormone in pregnant women, most of which are due to elevated estrogen levels in the pregnant woman’s body. In addition, there are other causes of high thyroid stimulating hormone in pregnant women: the level of thyroid binding globulin rises in early pregnancy, and the elevation of thyroid binding globulin increases thyroxine and triiodothyronine in the serum, but does not affect free T3 and T4, which have important physiological functions. In addition, there are other causes of high thyroid hormones in the body.