Hypothyroidism can affect women’s pregnancy in three ways: First, hypothyroidism can affect the female gonadal axis, leading to sporadic ovulation or anovulation, delayed menstruation, low menstrual flow, and even amenorrhea. Irregular ovulation, thin endometrium and low menstrual flow can affect the union of sperm and egg and the fertilization of the egg, thus affecting the pregnancy of women. Secondly, hypothyroidism can lead to delayed embryonic development or even embryonic arrest in the early stages of pregnancy, so it can affect the patient’s pregnancy. Thirdly, hypothyroidism can affect the mental development and physical development of the fetus, and eventually lead to the fetus becoming a cretin.