Hyperthyroidism or hypothyroidism during pregnancy may have serious effects on the fetus. If the thyroid gland does not function properly during pregnancy, it may seriously affect the fetus’ mental development, resulting in abnormal fetal mental development and fetal mental retardation, which may affect neurological development or congenital stupidity after birth. During pregnancy, it is important to be examined and treated with medication in a timely manner after the condition is determined. If you have hyperthyroidism during pregnancy, you can take methimazole or propylthiouracil, which has a thyroid controlling effect. If not taken properly, it can also affect the growth of the fetus, and you need to pay attention to review while taking the medication.