In recent years, with the progress of society and medical research, human health has generally improved and the average life expectancy has increased significantly, and people are increasingly concerned about the health and development of their offspring. Since the American College of Endocrinology took the lead in publishing the “Management of thyroid dysfunction in pregnancy and the postpartum period: Clinical Practice Guidelines of the Endocrine Society” in 2007, medical experts from various countries have published their own treatment protocols for thyroid disorders in pregnancy and the postpartum period. It is of high practical value in guiding the diagnosis and treatment of thyroid disorders during pregnancy and postpartum. The thyroid gland is an inconspicuous butterfly-shaped gland in the neck of the human body, only 20-25 grams in size, but the thyroxine it secretes plays an irreplaceable regulatory role in maintaining the normal physiological functions of the human body throughout life, like a gas pedal of human physiological functions. Many external factors, drugs, food, and changes in our own immune status may cause abnormal thyroid function, resulting in insufficient or excessive secretion of thyroxine, causing common abnormalities such as hypothyroidism, hyperthyroidism, subclinical hypothyroidism, and subclinical hyperthyroidism. If these thyroid abnormalities are not detected and intervened early, they may cause infertility, fetal abortion, miscarriage and stillbirth in women, and some of the children born will have serious problems such as short stature and mental retardation, which will bring immeasurable losses to themselves, their children and families. In fact, thyroid function testing is very simple. A simple visit to the hospital to draw a tube of blood can clarify the functional status of the thyroid gland, and combined with thyroid ultrasound and other tests, most thyroid disorders can be accurately diagnosed. For women who are preparing to get pregnant, what could be more worthwhile than paying a little more for the pain or discomfort of a routine physical exam and a side check of thyroid function, which may eliminate some regrets for life? The most common people who come to the clinic to consult about thyroid disease are those who have had repeated infertility, unexplained abortions and miscarriages and have had their thyroid function checked in the obstetrics and gynecology department, and those who have found various problems with their thyroid function after pregnancy. Will hypothyroidism really affect the child’s mental development? And, can hypothyroidism be cured? First of all, the first two questions can be answered together: clinical hypothyroidism (also known as hypothyroidism), including subclinical hypothyroidism, may cause both infertility and miscarriage, and may also adversely affect the neurological development of the child. These have been recognized by the international medical community and are included in national guidelines for thyroid disorders. This is why obstetricians, gynecologists and endocrinologists are now placing more emphasis on recommending thyroid function and thyroid antibody testing in pregnant women who are preparing for pregnancy and in those who are already pregnant. The third question: can hypothyroidism be cured. There are many causes of hypothyroidism, such as inflammation of the thyroid gland, overdose of antithyroid drugs, thyroid surgery, radioactive iodine treatment, etc. These causes are different, but their essence is similar: they all directly or indirectly reduce the production or secretion of thyroxine. Therefore, it is necessary to take thyroxine drugs for life to supplement the normal physiological activities of the body, just as it is necessary to eat every day to meet the energy needs of the body. In comparison, synthetic thyroxine preparations have a single component and a constant dose, so they are stable and have fewer adverse effects, and are classified as Class A by the U.S. Food and Drug Administration (FDA). In contrast, the thyroid tablets extracted from animal thyroid gland may have a certain difference in the content of thyroxine between batches due to the instability of the source itself, and the pharmacological effects may also vary accordingly. Therefore, doctors recommend the use of thyroxine to treat hypothyroidism or subclinical hypothyroidism in pregnant women, in order to keep the thyroid function in the ideal state more stably and to avoid the danger of thyroid disease to the pregnant woman and the fetus.