Congenital heart disease is one of the common congenital malformations in children, which is caused by the abnormal development of heart and blood vessels during the fetal period, with an incidence of 7‰-8‰, and children with severe malformations die weeks or months after birth. Since the 1950s, with the rapid development of medical technology, most children can grow up healthier after medical and surgical treatment, so they should be diagnosed as early as possible, with clear types and reasonable treatment, so as not to lose the time of surgery and strive for the best results. The causes of congenital heart disease are many, and at present the factors related to the causes of congenital heart disease are mainly the following five categories: congenital heart disease cause one: factors of fetal development environment Viral infection in utero is the most important cause of congenital heart disease, among which rubella virus infection is the most prominent, followed by coxsackie virus infection. If a mother has rubella in the first trimester, she will have a higher incidence of congenital heart disease in her baby; the most common causes are ductus arteriosus and pulmonary valve stenosis. This is due to the fact that the development of the large blood vessels of the fetal heart takes place during the second to eighth week of gestation, when viral infections in the uterus are sufficient to affect the development of the fetal heart. Other causes such as lesions of the amniotic membrane, fetal compression, pre-eclampsia in early pregnancy, maternal malnutrition, diabetes, phenylketonuria, hypercalcemia, and the use of radiation and cytotoxic drugs in early pregnancy are all causes of congenital heart disease in the fetus. Certain drugs taken by the mother during pregnancy can also lead to fetal heart malformations. Congenital heart disease cause 2: Premature birth Premature birth is an important cause of congenital heart disease. There are more preterm infants with ventricular defects and ductus arteriosus, the former being related to the fact that the ventricular septum does not have enough time to complete its development before birth, and the latter being related to the fact that the vasoconstrictor response in preterm infants is not strong enough after birth. Newborns weighing less than 2500g at birth are particularly susceptible to congenital heart disease. Congenital heart disease causes three: plateau environment Low oxygen partial pressure in the plateau is one of the causes of congenital heart disease; congenital heart disease in the plateau area – more arteriovenous ductus arteriosus and congenital heart disease atrial defect. The prevalence of this disease is much higher in Qinghai plateau in China than in plain areas. Congenital heart disease causes four: genetic factors Genetic factors are also one of the causes of congenital heart disease. In a family, brothers and sisters or parents and children suffer from congenital heart disease at the same time, as well as many cases of chromosomal abnormalities of genetic diseases with cardiovascular malformations, indicating the existence of genetic factors for this disease. Genetic studies have concluded that most congenital heart diseases are formed by the interaction of multiple genes and environmental factors. Congenital heart disease cause 5: other factors Advanced age is also one of the causes of congenital heart. Mothers of advanced age (35 years or older) are at greater risk of having babies with tetralogy of Fallot and Down syndrome. Some congenital heart diseases have significant differences in incidence between the sexes.