The thyroid gland is located in the neck below the thyroid cartilage, on both sides of the trachea, and is shaped like a butterfly, like a shield armor. The main function of the thyroid gland is to synthesize thyroid hormones, which have the function of promoting growth and development, energy production, protein synthesis, fat metabolism, oxygen utilization and other metabolic regulation of the body, and maintaining the excitability of the nervous system. Is thyroid function related to fertility? Hypothyroidism (hypothyroidism) has been found to be associated with infertility. Severe hypothyroidism causes ovarian failure to ovulate, menstrual disorders, and even amenorrhea. Hypothyroidism may also cause luteal insufficiency and insufficient secretion of progesterone, resulting in inadequate conversion of endometrial secretion, which is not conducive to the fertilization of eggs and can lead to infertility or habitual abortion. Some hypothyroid patients may compensate for elevated prolactin. Hypothyroidism in pregnant women also affects the development of neurointelligence in children. It is also important to be alert to subclinical hypothyroidism before and during pregnancy, i.e. elevated blood thyroid stimulating hormone (TSH) with or without thyroid hormone abnormalities. It is recommended that TSH does not exceed 2.5 mIU/L during pregnancy preparation and early pregnancy. Severe hyperthyroidism (hyperthyroidism) can lead to infertility, and it is not certain whether mild or moderate hyperthyroidism will lead to infertility. Severe hyperthyroidism should be controlled before pregnancy. TPOAb is the gold standard for the diagnosis of Hashimoto’s thyroiditis and indicates potential thyroid impairment; the presence of both TgAb and TPOAb indicates the severity of thyroid impairment. Thyroid autoantibodies are associated with miscarriage, premature birth, infertility, placental abruption, perinatal death, and postpartum thyroiditis. Therefore, in preparation for pregnancy, it is important to have a complete assessment of thyroid function.