1. Hyperthyroidism and infertility (1) What is hyperthyroidism? Hyperthyroidism, referred to as hyperthyroidism, is caused by the synthesis and release of excessive thyroid hormones by the thyroid gland, resulting in hyper-metabolism and sympathetic excitement, palpitations, sweating, easy hunger, increased frequency of bowel movements and weight loss. Both men and women can develop the disease, but it is more common in young and middle-aged women, and the prevalence of women is 4-6 times higher than that of men. People with high mental stress and abnormal immune function are more likely to suffer from hyperthyroidism. (2) How does hyperthyroidism cause infertility? Hyperthyroidism not only causes other hormonal abnormalities, but also causes nutritional disorders and emotional changes. Women with hyperthyroidism often have menstrual disorders in combination. In the early stage of hyperthyroidism, the synthesis and secretion of ovarian hormones increase, causing excessive endometrial hyperplasia, which manifests as excessive menstruation, frequent menstruation, prolonged periods, as well as dysmenorrhea and premenstrual tension, all of which reduce their fertility. Advanced hyperthyroidism can lead to ovulation dysfunction and sex hormone secretion disorder, resulting in follicular development arrest, anovulation, scanty menstruation or even amenorrhea. Severe hyperthyroidism can lead to infertility. In addition, even after pregnancy, patients with hyperthyroidism are at a much higher risk of fetal growth retardation, stillbirth, miscarriage and premature birth. 2. Hypothyroidism and infertility (1) What is hypothyroidism? Hypothyroidism, referred to as hypothyroidism, is a group of endocrine disorders caused by a decrease in the synthesis or secretion of thyroid hormones and a decrease in the metabolic activity of the body. Hypothyroidism is more common in women than in men, and the incidence of hypothyroidism in women of childbearing age between 20 and 40 years old is about 2% to 4%. Some studies have found that the prevalence of hypothyroidism is significantly higher in patients with infertility. (2) How does hypothyroidism cause infertility? Patients with hypothyroidism usually present with chilliness, lassitude, fatigue, indifference, thick lips and large tongue, anorexia, bradycardia, memory loss and loss of libido. Women with hypothyroidism also tend to have irregular menstruation, excessive menstrual bleeding or amenorrhea, ovulation disorders and ovarian atrophy. In women with hypothyroidism, decreased libido and dissatisfaction with sexual life are also indirect causes of infertility. Pregnancy combined with hypothyroidism is prone to adverse pregnancy outcomes such as miscarriage, pre-eclampsia, eclampsia and placental abruption. Even if the baby can be born successfully, the infant is prone to congenital goiter or cretinism and other congenital malformations, so hypothyroidism before or during pregnancy should be detected early and treated in time to improve the ability to conceive and ensure normal fetal growth and development. 3.Which women preparing for pregnancy are at high risk of thyroid disease? At present, it is recommended that pregnant women should be screened for thyroid function before pregnancy, especially women with the following high-risk factors: history of thyroid insufficiency, history of thyroid surgery, positive thyroid antibodies, family history of thyroid disease, history of recurrent miscarriages, infertility, age 30 or older, obesity, history of head and neck radiation therapy, use of drugs affecting thyroid function, type I diabetes or other autoimmune diseases. Those with a history of thyroid disease, family history of recurrent miscarriages, infertility, age 30, obesity, history of radiation therapy to the head and neck, use of medications that affect thyroid function, type 1 diabetes or other autoimmune diseases should have thyroid-related tests in advance and be treated as soon as possible to lay the foundation for successful conception and a healthy baby.