Congenital heart disease is a cardiovascular disease that occurs at birth. About 7‰ to 11‰ of babies born each year in China have congenital cardiovascular anomalies, which can cause great harm to both the affected children and their families. Congenital heart disease is caused by the interaction of many complex factors. This is why it is important to take precautions before and even during pregnancy to effectively reduce the risk of developing congenital heart disease. So, what are the “culprits” that lead to congenital heart disease? The most important cause of congenital heart disease is viral infection in utero, the most prominent being infection with rubella virus, followed by coxsackie virus infection. If the mother has rubella within the first trimester, the baby has a higher chance of having congenital heart disease; the most common ones are ductus arteriosus and pulmonary valve stenosis. In addition, other phenomena such as fetal compression, amniotic reaction, maternal malnutrition, pre-eclampsia, phenylketonuria, diabetes mellitus, hypercalcemia, application of radiation and cytotoxic drugs in early pregnancy are all factors that can lead to congenital heart disease in the fetus. Premature birth Premature birth is one of the most important causes of congenital heart disease. Premature infants suffer more from ventricular defect and ductus arteriosus, the former before birth and the ventricular septum does not have enough time to complete the development, the latter after birth with the vasoconstriction response of preterm infants has not reached strong enough. Newborns with birth weight below 2500g are especially prone to congenital heart disease. 3, plateau environment The low partial pressure of oxygen in the plateau is one of the causes of congenital heart disease. There are more congenital heart disease – ductus arteriosus and congenital heart disease atrial defect in the plateau area. The prevalence rate in Qinghai plateau area of China is much higher than that in plain areas. 4.Heredity Genetic factors are one of the important causes. In a family, there are cases of siblings or parents and children suffering from congenital heart disease together, as well as many cases of chromosomal abnormalities related to genetic diseases with cardiovascular malformations, which suggest the existence of genetic factors for congenital heart disease. The results of genetic research indicate that most congenital heart diseases arise as a result of the interaction of multiple genes and surrounding environmental factors. 5, other factors Advanced age group is also congenital heart disease population. Advanced maternal age, meaning women over the age of 35, are more likely to give birth to babies with tetralogy of Fallot and Down syndrome. Some congenital heart diseases have significant male-female differences in incidence. Pregnant women must pay attention to supplemental nutrition during the first 3 months of pregnancy, refrain from random medication, avoid contact with radiation, actively participate in outdoor activities, adhere to exercise, strengthen resistance and prevent infection. In addition, as long as congenital heart disease is detected in time, diagnosed as early as possible, and the timing of surgical treatment is grasped, satisfactory treatment results can generally be achieved.