Hypothyroidism and hyperthyroidism are common clinical endocrine disorders that not only affect health, but may also lead to infertility and miscarriage. 1, the impact of hypothyroidism on pregnancy: hypothyroidism is short for hypothyroidism, which is a series of disease manifestations due to the absolute or relative shortage of thyroid hormones, resulting in a decrease in the metabolic process of the body. The experts at Jinan Jiale Reproductive Hospital point out that hypothyroidism, whether in men or women, has an impact on pregnancy: a. Hypothyroidism leads to scanty menstruation and even amenorrhea in female patients. The onset of hypothyroidism in adulthood is often accompanied by anovulation, menstrual disorders, hypogonadism and infertility, and women with hypothyroidism often have a history of spontaneous abortions, stillbirths and neonatal malformations. b. Hypothyroidism also affects male patients, causing male impotence, delayed sexual maturity, backward paraphilia, decreased libido, impotence and testicular atrophy, etc., resulting in infertility and difficulty in having a healthy baby. 2. Effects of hyperthyroidism on pregnancy Among hyperthyroidism patients, there are obviously more women than men, especially young women aged 20-30. Because women in this age group have active endocrine secretion, if they are in a state of long-term tension, fatigue and staying up late, they are likely to induce hyperthyroidism. a. In the early stage of female hyperthyroidism, excessive secretion of estrogen and hyperplasia of endometrium manifest as excessive and frequent menstruation, and even dysfunctional uterine bleeding, which reduces the chance of conception and easily causes miscarriage after pregnancy. In the late stage of hyperthyroidism, the dysregulation of GnRH-Gn/TRH-TSH secretion leads to ovulatory dysfunction and disruption of sex hormone secretion in the ovaries, resulting in follicular arrest, follicular atresia, anovulation, menorrhagia, amenorrhea and infertility. b. In men, hyperthyroidism can cause spermatogenic dysfunction, which may also lead to infertility.