Congenital heart disease (congenital heart disease) is the most common of all fetal anomalies, with an incidence of about 8 per 1,000, of which the incidence of severe congenital heart disease is about 4 per 1,000. Due to the complexity and difficulty of postnatal surgery, it leads to a very high mortality rate and infant morbidity. According to statistics, severe precocious heart disease accounts for 20% of stillbirths, 30% of neonatal deaths due to congenital defects, and more than half of childhood deaths due to precocious heart disease. Therefore, timely prenatal detection, timely diagnosis and timely intervention are very important. The epidemiological survey by Zhiwei Hu, Department of Cardiac Surgery, Wuhan Union Hospital, found that although the incidence of precocious heart disease is high in high-risk groups, most of them are sporadic with no obvious high-risk factors (85%-90% of all precocious heart diseases), so screening for cardiac malformations has been made routine. Through screening, high-risk groups for precocious heart disease are delineated, and these cases are then further examined. I. High-risk factors for precocious heart disease 1. High-risk medical or family history of precocious heart disease: (1) Pregnant women with a family history of precocious heart disease have a risk rate of 1:50 for fetal heart abnormalities; if one of the couple has precocious heart disease or has delivered a child with a heart abnormality, the risk rate of fetal heart abnormalities in another pregnancy is 1:10. (2) Pregnant women have syndromes or abnormalities related to heart abnormalities in themselves or in their families. (3) Pregnant women with certain medical conditions, such as poorly controlled diabetes mellitus, have a 5% chance of fetal precocious heart disease; pregnant women with connective tissue disease have a significantly higher incidence of fetal atrioventricular block; fetuses of pregnant women with phenylketonuria are susceptible to ventricular septal defect, aortic constriction, hypoplastic left heart syndrome, and tetralogy of Fallot. (4) Exposure to certain substances or drugs during pregnancy, such as alcohol, lithium, vitamin A, anticonvulsants, reaction stops, steroids, amphetamines, narcotics and oral contraceptives, the chance of fetal heart malformation is 1:50 high doses of radiation, intrauterine infections (such as rubella virus, cytomegalovirus, coxsackievirus) may cause fetal heart malformation. 2. Clinical or laboratory tests suggest a high risk of precordial disease: (1) The heart should be suspected to have defects if normal fetal heart section images are difficult to obtain by conventional ultrasound (2) abnormal cardiovascular symptoms such as thickening of the nuchal translucency (NT) and abnormal blood flow in the ductus venosus DV in early pregnancy, thickening of the nuchal fold in mid pregnancy, cardiac arrhythmia, non The thicker the NT in early pregnancy, the thicker the nuchal fold in midtrimester, arrhythmia, and non-immune fetal edema. The thicker the NT in early pregnancy, the higher the incidence of fetal heart malformations. Therefore, in cases of nuchal thickening, it is important to have the heart examined by an experienced ultrasound professional after 18 weeks of gestation. Cases with thickened NT from 11 to 13+6 weeks of gestation that also have DV atrial systolic flow regurgitation or tricuspid regurgitation have an increased risk rate of fetal precordial disease. (3) Early onset symmetric fetal growth restriction. (4) Routine ultrasound reveals certain extracardiac malformations (e.g., abnormal heart position), central nervous system disorders (e.g., ventricular dilatation, microcephaly, agenesis of the corpus callosum, cerebral bulge) that are prone to combined cardiac anomalies; diaphragmatic hernia, gastrointestinal atresia, visceral inversion, abdominal wall defects (e.g., umbilical bulge), renal dysplasia, and single umbilical artery are also often combined with cardiac anomalies. (5) The risk rate of cardiac malformation is significantly higher in pregnant women over 35 years of age, those with serological screening results showing high risk of chromosomal abnormalities, or those with known fetal chromosomal abnormalities. The incidence of chromosomal abnormalities in fetuses with prenatal detection of cardiac malformations is 25% to 30%. The combined cardiac anomalies vary by chromosomal abnormality. The most common cardiac anomaly in trisomy 21 is endocardial cushion defect; trisomy 18 is ventricular septal defect and/or multiple valvular anomalies; trisomy 13 is ventricular septal defect or endocardial cushion defect, valvular anomalies, aortic stenosis or permanent arterial trunk; and 45,XO is aortic constriction and left heart dysplasia. Of these four common chromosomal abnormalities, aortic isthmus stenosis is common. (6) There is an increased incidence of twin pregnancies, especially single chorionic vesicle single amniotic vesicle twin cardiac anomalies.