Many parents, upon learning that their child has congenital heart disease, want to know the cause of the disease, have multiple guesses, and even develop feelings of self-blame and guilt. In fact, at the stage of fetal heart development, any factor that affects the normal development of the heart may cause congenital heart disease. There are many factors related to the pathogenesis, which can be roughly divided into endogenous and exogenous factors. Intrinsic factors: It is currently understood that they are mainly related to genetics, including single gene disorders, polygenic disorders and chromosomal variants. It has been reported that more than 10% of precardiac diseases have some degree of family history of occurrence. Extrinsic factors: If the mother has a viral infection during pregnancy, especially in the first trimester, the fetus is susceptible to precocious heart disease, and the main causative viruses are rubella virus, influenza virus and coxsackie virus. Other factors such as exposure to high doses of radiation, diabetes, hypercalcemia and other metabolic disorders; taking certain teratogenic drugs during pregnancy; consuming water and food contaminated with chemicals, etc. In addition, older pregnant women, especially those who are close to the age of menopause, are prone to fetal precocious heart disease. Therefore, the main measure to avoid the occurrence of precardiac disease is prevention. It is important to strengthen the health care of pregnant women, especially to actively prevent viral infectious diseases such as rubella and influenza and to avoid factors associated with the onset of the disease in early pregnancy.