Thyroid disorders are the second most common endocrine disorder after diabetes, so it is common for thyroid disorders to occur during pregnancy. According to a survey, 1 in 10 mothers-to-be may be affected by thyroid disease. In order to welcome a healthy and smart baby, don’t ignore thyroid disorders during pregnancy. The thyroid gland is a very important endocrine gland in the body, located below the thyroid cartilage in the neck and on both sides of the trachea. Its main function is to synthesize and secrete thyroid hormones and regulate the body’s metabolism. If the function of the thyroid gland is low and too little thyroid hormone is produced, this can lead to “hypothyroidism”. People with hypothyroidism consume energy slowly and have a slower metabolism. On the contrary, a high functioning thyroid gland synthesizes and releases too much thyroid hormone into the blood, causing “hyperthyroidism” and accelerating the body’s metabolic process. It is worth noting that thyroid function is a great challenge during pregnancy: before 12 weeks, the fetus’ own thyroid function is not yet complete, and the thyroxine needed for fetal growth and development comes entirely from the mother; from 12 to 20 weeks, the fetus’ thyroid function gradually develops, and it can synthesize its own thyroid hormone, but part of the thyroxine needed still comes from the mother; after 21 to 24 weeks, as the fetus’ thyroid function develops and matures, it starts to use its own thyroid hormone to synthesize thyroid hormone. After 21-24 weeks, as the fetus develops and matures, it starts to use its own thyroid hormone as the main source, supplemented by the mother’s thyroid hormone. Because of this developmental process of fetal thyroid function, maternal thyroid disorders during pregnancy have a significant impact on fetal development. For example, hypothyroidism during pregnancy becomes one of the factors causing neurointellectual impairment in the offspring. If the mother has hypothyroidism during this period, i.e., the mother’s thyroid hormone level is continuously low and cannot provide sufficient thyroid hormones for fetal brain development, it will affect fetal brain development and even cause irreversible damage. A positive thyroid autoantibody, another thyroid disorder during pregnancy, can greatly increase the incidence of miscarriage and preterm delivery. Graves’ disease (toxic diffuse goiter) accounts for 85% of hyperthyroidism (hyperthyroidism) during pregnancy. If hyperthyroidism is not controlled in time, the rate of miscarriage, hyperemesis gravidarum, preterm birth, small sample babies and perinatal mortality are significantly higher in pregnant women. Of course, thyroid disorders during pregnancy also include many other disorders, such as isolated hypo-T4emia during pregnancy, thyroid nodules including malignant nodules found during pregnancy, and transient hyperthyroidism due to severe pregnancy vomiting. All of these require prompt consultation and treatment at the hospital. How to prevent and treat thyroid disorders during pregnancy First, screening for thyroid disorders is recommended before pregnancy for women with a history of thyroid disorders or family history, a history of goiter and thyroid surgery, isotope iodine therapy, previous elevated serum thyroid stimulating hormone or positive autoantibodies to the thyroid gland, and a history of other autoimmune disorders or family history. Currently, due to the increased prevalence of thyroid disease during pregnancy, timely thyroid function tests may also be considered after pregnancy is clear to detect abnormal thyroid function early and to avoid damage to the pregnant woman and her fetus from thyroid disease during pregnancy. If thyroid disorders are found after pregnancy, it is important to visit the hospital in time because the treatment of thyroid disorders during pregnancy is very different from that of thyroid disorders during non-pregnancy, for example, the choice of the type of medication, the dosage of medication, etc. need to be carefully selected. In addition, thyroid hormone levels should be monitored well during pregnancy. Since some symptoms of thyroid disease, such as weight gain, weakness and swelling, can easily be mistaken for pregnancy and ignored, special attention should be paid to identify them. In terms of diet, pregnant women should eat more iodine-containing foods such as seaweed, nori and sea fish during pregnancy to ensure the fetus’ need for iodine, and if necessary, urinary iodine can be monitored regularly.