Hypothyroidism in pregnant women is theoretically not hereditary, but if a pregnant woman has hypothyroidism before pregnancy, it is recommended that the patient should get it under control first, and in the short term it is best to get the thyroid stimulating hormone level under control as soon as possible to the required range. The main purpose is to reduce the impact on the fetus. After treatment, the patient’s thyroid function is in normal condition, and the medication is used under the guidance of the doctor, the impact on the next generation is very little, and the side effects of the basic medication are not very big, and the medication can be taken during the whole pregnancy. If the control hormone level is normal, the effect on the fetus is also not significant and is very safe. If you do not have hypothyroidism before, but after pregnancy you find that you have hypothyroidism or subclinical hypothyroidism, you should take medication according to your hormone level. For example, thyroid stimulating hormone, TSH is required to be 2.5mIU/L internationally, 2.5mIU/L in early pregnancy and 3mIU/L or less in middle and late pregnancy, which has the least impact on the fetus and is beneficial to the fetal development.