1. What is the effect of pregnancy on hyperthyroidism? Doctors have different opinions on this issue. Most people believe that the placenta secretes thyrotropin-releasing hormone (TRH) and chorionic gonadotropin (HCG) during pregnancy, which can increase thyroid function and worsen the condition of hyperthyroidism. However, some researchers believe that pregnancy does not have a significant effect on hyperthyroidism. In practice, most hyperthyroid patients can safely go through pregnancy and delivery with proper treatment and obstetric supervision. 2. What is the effect of hyperthyroidism on pregnancy? As mentioned earlier, it has little effect on pregnancy in mild cases, but in severe cases, due to the strong excitability of nerves and muscles, it can easily cause uterine contractions leading to miscarriage and preterm delivery. Various metabolic abnormalities increase the incidence of hyperemesis and stillbirth. Increased energy consumption reduces the available energy, which may lead to weak contractions during labor. A protein called long-acting thyroxine can be found in the blood of hyperthyroid patients, which can enter the fetus through the placenta and cause fetal hyperthyroidism, also known as congenital hyperthyroidism. In some cases, the congenital hyperthyroidism gradually subsides only after 3-4 weeks of life. In this case, the fetal and neonatal mortality rate is higher. Another effect of hyperthyroidism on pregnancy is due to the use of drugs, such as the commonly used thioureas (methyl and propylthiouracil), which can enter the fetus through the placenta and cause fetal hypothyroidism or even fetal malformation. Therefore, patients with mild hyperthyroidism should try not to use or use less anti-thyroid drugs. 3. Does thyroid crisis occur in pregnancy? Yes, it can happen. Once it happens, the maternal mortality rate is high. Fortunately, the chance of occurrence is low. Thyroid crisis is a serious symptom that worsens in hyperthyroid patients and can occur in various emergency situations, such as surgery, childbirth, infection and trauma. The main manifestations are: high fever, body temperature above 39°C, and accelerated pulse rate, which can reach 140-160 beats per minute or more. Severe heart rate arrhythmias can be found when an electrocardiogram is done. Patients often look anxious, irritable, sweating profusely, nausea, vomiting, diarrhea, which can lead to deficiency, shock, and even coma. These conditions are life-threatening and require the participation of experienced obstetricians and endocrinologists. Commonly used resuscitation measures are: (1) lowering temperature; (2) giving iodine preparations; (3) increasing the dose of antithyroid drugs; (4) applying symptomatic treatment drugs such as insulin and dexamethasone, adjusting water and electrolyte disorders and acid-base imbalance in time. (5) The delivery should be ended 2-4 hours after the condition is stabilized, and the choice of vaginal delivery or cesarean delivery should be made according to the obstetric situation. 4.What things should be noted in the treatment of pregnant women with hyperthyroidism? (1) Treatment with radioactive iodine is strictly prohibited after 12-14 weeks of pregnancy because it may cause permanent hypothyroidism in the fetus and newborn. (2) The dosage of anti-thyroid medication should be small, usually half the amount of non-pregnant medication. Propylthiouracil rarely affects the fetus through the placenta, so it can be the drug of choice. (3) Surgery may be considered for those with obvious enlargement of the thyroid gland and symptoms of pressure, or those whose condition cannot be controlled by medication. Theoretically, surgery at 16-20 weeks of gestation is appropriate. However, in practice, those with more severe disease should be advised to use contraception and wait for treatment to improve before considering pregnancy. And if the disease progresses rapidly during pregnancy, termination of pregnancy should be considered first. There are many problems with thyroid surgery during pregnancy and special care should be taken. 5.What special treatment should be done for hyperthyroidism patients after pregnancy? (1) Prenatal checkups and fetal monitoring should be strengthened during pregnancy, and hospitalization for delivery should be advanced (usually around 36 weeks) so that the doctor can have a full understanding and preparation of the condition. (2) Vaginal delivery is the preferred mode of delivery, and mental comfort and sedative drugs should be given during labor to reduce the stimulation of pain to the mother. At the same time, attention should be paid to the administration of oxygen, energy and shortening the second stage of labor, and if indicated, caesarean section can also be chosen. (3) Prevent infection before and after delivery to prevent complications and thyroid crisis. (4) Because the secretion of antithyroid drugs through breast milk can affect the newborn, it is not advisable to breastfeed if you need to continue taking drugs after delivery. (5) The thyroid function of the newborn should be checked and timely measures should be taken if abnormalities are found.