The effect of hyperthyroidism on the fetus should be considered from several aspects: 1. Hyperthyroidism affects the mother, there may be hypertension, miscarriage, and the child will be premature in utero; 2. The child will have restricted development and miscarriage situation; 3. In case of hyperthyroidism, the pregnant woman is bound to take oral anti-thyroid, drugs that inhibit thyroid function, such as methylthioxypyrimethamine and propylthioxypyrimethamine, methimazole. In the early stages of pregnancy if you take drugs, may lead to the occurrence of fetal malformations; 4, hyperthyroidism should be treated before pregnancy, in the early stages of pregnancy if the pregnant woman in the case of various indicators allow, early try not to take oral anti-thyroxine drugs. You can take them again after 16 weeks of pregnancy. If a pregnant woman has hyperthyroidism, the drugs have a teratogenic effect on the child and are prone to premature birth. It is also easy to deliver prematurely when it causes hypertension in the mother, resulting in a restricted development of the child.