Abnormal thyroid function refers to abnormal thyroid function, and abnormal thyroid function may affect pregnancy. Abnormal thyroid function generally refers to hyperthyroidism or hypothyroidism. Female patients with hyperthyroidism are prone to decreased menstrual flow, not easy to get pregnant due to hypermetabolic syndrome, and prone to preterm labor and miscarriage after pregnancy. Female patients with hypothyroidism are prone to increased menstrual flow, infertility, and after successful pregnancy, fetal development will also be affected, which may lead to mental retardation during the fetal stage and cretinism after birth. Abnormal thyroid function in men will affect the male reproductive system, resulting in decreased libido, erectile dysfunction, decreased sperm count, etc., which will also affect normal pregnancy. It is recommended that patients with thyroid dysfunction be treated before considering pregnancy.