Where is the thyroid located and what is its function? What is abnormal thyroid function? In fact, in the middle of our neck, there is an organ shaped like a purple butterfly, which is the thyroid gland. The thyroid gland is an important endocrine organ that regulates the body’s metabolism and also affects the reproductive function of women. Abnormal thyroid function is more common in people of childbearing age, and the incidence is four to five times higher in women than in men. When women have abnormal thyroid function, they are prone to menstrual disorders, reduced chances of conception, and unfavorable pregnancy outcomes, and may have long-term effects on the health of their offspring. The thyroid gland controls the body’s metabolism by secreting thyroid hormones, and when it secretes too much thyroxine, it can become hyperthyroid, or “hyperthyroidism”. If you have “big neck disease”, your neck will become thicker, your appetite will be good, your mood will be high, and you will still be surprisingly thin. Hypothyroidism, commonly known as “hypothyroidism”, occurs when there is insufficient secretion of thyroxine, and very few people know about the latter. Generally speaking, the symptoms of hypothyroidism are the opposite of those of hyperthyroidism, as people with hypothyroidism lose their appetite, lose energy, are afraid of cold, and are depressed all day. However, these symptoms are not specific and are quite similar to many sub-health conditions in the human body, so many patients do not realize they are sick, as in the case of Xiao Zhang we just mentioned. In addition to the above mentioned clinical hyperthyroidism or clinical hypothyroidism, some women’s thyroid function tests fail to meet clinical diagnostic standards and are often referred to as “subclinical hyperthyroidism” or “subclinical hypothyroidism”. Endocrinologists believe that the occurrence of “subclinical hypothyroidism” has a great relationship with mental stress. “What are the consequences of subclinical hypothyroidism? According to some studies, women with subclinical hypothyroidism have a very low pregnancy rate and may be clinically infertile, and even if they are pregnant, the probability of early miscarriage is relatively high. It is important to note that because hypothyroidism is clinically asymptomatic and easily overlooked, routine thyroid function tests are necessary in patients with a history of spontaneous abortion. It has been reported that the incidence of hypothyroidism in infertile women is significantly higher, with 40.0% and 15.4% incidence in patients with ovarian failure and ovulation disorders, respectively. In a study of 25,756 pregnant women, 404 cases of hypothyroidism were compared with 15,689 cases of normal pregnant women, and the risk of preterm delivery was found to be twice as high as that of normal pregnant women. Pregnant women with hypothyroidism can also suffer from depression (including postpartum depression). Hypothyroidism during pregnancy can directly affect the neurological development of the fetus, making the baby less intelligent. Another clinical abnormality of thyroid function is thyroid autoimmune disease, which refers to a positive thyroid peroxidase (TPO~AB) and/or thyroglobulin TG~AB, but normal thyroid function tests. This disease accounts for 5-8% of women of childbearing age, who suffer from unexplained infertility, miscarriage, recurrent miscarriage, preterm delivery, and postpartum thyroiditis. One study of 438 women who were first-time infertility clinic attendees and a control group of 100 age-matched menstruating women with normal fertility showed that the relative risk of thyroid autoimmune disease in infertile women was 2.25 times higher than in normal women. Whether to routinely screen all pregnant women for thyroid function is still controversial. It has been suggested that due to the increased demand for thyroxine after pregnancy, abnormal function can still occur in those with normal prenatal thyroid function tests, and many patients are found to have abnormal thyroid function only at 8-10 weeks of prenatal examination, when it is too late for treatment. The latest 2012 Chinese guidelines for the diagnosis and treatment of thyroid disease in pregnancy suggest that screening for thyroid function: high-risk groups refer to those with positive thyroid autoantibodies, type I diabetes, other autoimmune diseases, infertile women, women with BMI > 40, women over 30 years old, and women with a history of miscarriage or preterm delivery; screening in high-risk pregnancy groups still has a 30-80% missed diagnosis rate; screening the entire pregnancy population is better than no screening The screening of the entire pregnancy population is better than no screening; preconception screening and screening before 8 weeks of pregnancy are recommended. Most experts believe that the potential threat of irreversible effects of hypothyroidism and subthyroidism on fetal brain development warrants routine thyroid screening in all women who are planning to become pregnant, and that pregnant women should be routinely screened for thyroid function at the time of pregnancy diagnosis and closely monitored throughout pregnancy. Finally, we will discuss the treatment of abnormal thyroid function. If mild hyperthyroidism is tolerated during pregnancy, anti-thyroid medication is generally not necessary, but in severe cases, propylthiouracil at the usual dose of 150-300 MG/D or tabazol at 15-30 MG/D should be used. If hyperthyroidism is detected before pregnancy, patients can be informed of the option of surgical removal of part of the thyroid gland or radioactive iodine treatment, which has the advantage of avoiding the risks associated with the use of medication during pregnancy. Once diagnosed with clinical hypothyroidism, do not panic, as you can work and live like a normal person if you take levothyroxine regularly. Two small studies have shown that levothyroxine supplementation significantly reduces the incidence of miscarriage and preterm delivery. It is important to note that women with clinical suboptimal risk pregnancies (risk factors include family history of thyroid disease, history of abnormal thyroid function who have signs and symptoms of hypothyroidism, thyroid gland abnormalities, type 1 diabetes or other autoimmune diseases) and a history of anemia, elevated cholesterol, infertility, habitual miscarriage and preterm delivery should also be treated accordingly. proposes that treatment of hypothyroidism: pre-pregnancy should be controlled to TSH <2.5 MIU/L before pregnancy; levothyroxine dose should be increased by 25-30% after pregnancy, with an increased amount of 2 days per week; dynamic monitoring during pregnancy, reduction to pre-pregnancy level after delivery, and review and adjustment of medication dose 6 weeks after delivery. In conclusion, the thyroid gland is an emotional organ and chronic stress can induce thyroid disease. Therefore, prevention of abnormal thyroid function requires learning to relieve stress in a timely manner. Iodine deficiency used to be an important cause of clinical or subclinical hypothyroidism, but with the widespread use of iodized salt, this problem has been solved. However, the daily consumption of iodized salt, combined with the frequent consumption of seafood and kelp in coastal areas, can also put pressure on the thyroid gland and trigger the disease. In addition, women are more susceptible to hypothyroidism than men, which is related to the physiological characteristics of women and the fact that the reproductive age is a vulnerable period for hypothyroidism in women's life. 2012 guidelines for the diagnosis and treatment of thyroid disease in pregnancy suggest that the recommendations for iodine intake in pregnancy are: excess: urinary iodine > 500UG/L, fetus will develop hypothyroidism with excess iodine; iodine deficiency affects fetal neurological development, supplementation with 150UG of iodine per day in addition to normal diet during pregnancy. Iodine deficiency affects the neurodevelopment of the fetus, so it is important to supplement the normal diet with 150 UG of iodine per day during pregnancy.