Viral infections. Viral infections during the first trimester, especially during the third to eighth weeks of pregnancy, can predispose the fetus to cardiovascular malformations. The rubella virus is the main culprit of fetal precocious heart disease. In addition, influenza, mumps, coxsackie virus, herpes virus, etc. are also often the “perpetrators” of pediatric precocious heart disease. Every year, about 7‰ to 11‰ of babies born in China are born with congenital cardiovascular anomalies, which bring great misfortune and heavy burden to families and society. According to modern medical research, there are seven high-risk factors that can cause malformations in fetal heart development: 1, there is a family history of congenital heart disease. It is not uncommon for siblings to suffer from congenital heart disease at the same time, or for parents and children to suffer from congenital heart disease at the same time, and the nature of the disease is very similar. If the first child born to a mother with congenital heart disease, the possibility of the second child suffering from the disease is about 2%; if two consecutive children are congenital heart disease, the number of children with congenital heart disease may increase to 10%. If the mother suffers from precocious heart disease, the risk of the second generation suffering from precocious disease is 10%. 2, pregnant women with untreated and uncontrolled diabetes mellitus, the risk of congenital heart disease in the fetus is 2%, if the disease is controlled and stable in early pregnancy, the risk decreases. 3, pregnant women exposed to teratogenic drugs in early pregnancy, such as lithium, sodium phenytoin or steroids, can lead to a 2% prevalence of fetal congenital heart disease. 4, early pregnancy by radioactive substances such as X-rays, isotopes and other excessive exposure. 5.Viral infection. Women in the first three months of pregnancy, especially the 3 weeks-8 weeks of pregnancy, if infected with viruses, the fetus is prone to cardiovascular malformations. Among them, rubella virus is the main culprit of fetal precocious heart disease. In addition, influenza, mumps, coxsackie virus, herpes virus, etc. are often the “perpetrators” of pediatric precocious heart disease. 6, consanguineous marriage. Consanguineous marriage is a high risk factor for fetal malformation and the occurrence of precocious heart disease. 7, bad habits. Pregnant women are addicted to “swallowing fog” or husband smoking, wife “passive smoking” can make fetal malformations or the occurrence of pediatric precocious heart disease. The incidence of pre-cardiac disease in infants, babies born to smoking mothers is two times that of non-smoking mothers. Conception after drinking” can cause chromosomal abnormalities in the fetus, and most babies born with alcoholism have cardiovascular abnormalities. Early detection of prediabetes is essential for eugenics. At 20-28 weeks of gestation, a fetal heart “defect” can be clearly detected using a cross-sectional ultrasound heart scanner. In addition, the presence of ascites or edema can be detected, which can lead to the detection of cardiac malformations in the fetus.