Propylthiouracil tablets are one of the preferred medications for hyperthyroidism in pregnancy. When used correctly, it will not affect the unborn baby. During pregnancy, if a pregnant mother has hyperthyroidism, the disease can have an impact on the pregnancy and may lead to miscarriage, premature birth, growth restriction of the baby, hypothyroidism and goiter. If hyperthyroidism is poorly treated or left untreated, it can also lead to hyperthyroid crisis during delivery or surgery, or in case of infection during pregnancy. Therefore, if a mother is diagnosed with hyperthyroidism, it is important to see a thyroid specialist regularly during pregnancy so that she can be treated with the appropriate medication.