As with other congenital heart diseases, it is now thought to be the result of a complex interplay of genetic and environmental factors, and the following factors may affect fetal development and produce congenital malformations. (1) Environmental factors of fetal development: Infections, viral or bacterial infections in the first trimester of pregnancy especially rubella virus and to a lesser extent coxsackievirus, have a higher incidence of congenital heart disease in infants born with them. Other: such as lesions of amniotic membrane, fetal compression, early gestational pre-eclampsia, maternal malnutrition, diabetes mellitus, phenylketonuria, hypercalcemia, application of radiation and cytotoxic drugs in early gestation, excessive maternal age, etc. all have the potential to cause congenital heart disease in the fetus. (2) Genetic factors: Most congenital heart disease is formed by the interaction of multiple genes and environmental factors. (3) Other: Some congenital heart diseases are more frequent in highland areas, and some congenital heart diseases have significant differences in incidence between male and female sexes, indicating that altitude and sex of birthplace are also related to the occurrence of this disease. Among patients with congenital heart disease, those who can find out the cause are very few, but strengthening health care for pregnant women, especially actively preventing rubella, influenza and other rubella viral diseases and avoiding all factors related to the onset of the disease in the early stages of pregnancy, is of positive significance to the prevention of congenital heart disease.