Congenital heart disease is a common congenital developmental malformation. According to statistics, the incidence of congenital heart disease is 8‰ to 1%, and there are 150,000 to 220,000 cases of children born with congenital heart disease each year in China. Congenital heart disease is one of the most common major organ malformations and a major cause of miscarriage, intrauterine fetal death, and infant mortality. Current studies have shown that fetal heart ultrasound has a sensitivity of 95% and an accuracy of over 85% in diagnosing fetal heart malformations. It can screen for most cardiac developmental anomalies, especially some serious malformations with poor prognosis, such as ectopic heart, single ventricle, single chamber heart, permanent arterial trunk, ventricular dysplasia, dissection or atresia of the great arteries, severe tetralogy of Fallot and valvular atresia. However, it is difficult to detect small ventricular septal defects, atrial septal defects, mild pulmonary stenosis, and mild tetralogy of Fallot. To diagnose congenital heart disease early and in time, it requires not only advanced examination equipment and experienced ultrasonographers, but also the cooperation and attention of pregnant women and their families. On the one hand, pregnant mothers should have regular maternity checkups on time, and on the other hand, they need to follow the medical advice and follow the obstetrician’s recommendation to make an appointment for a fetal system ultrasound or a special examination of the heart. For all pregnant women, it is necessary to have a fetal systemic ultrasound examination in the middle pregnancy, i.e. level III prenatal ultrasound diagnosis, which is especially suitable for patients with fetal malformations or suspected fetal malformations found or detected in general prenatal ultrasound (level I) or routine prenatal ultrasound (level II) or with high risk factors for fetal malformations. Fetal systemic ultrasound screens the fetal heart for the presence of malformations of the developing heart. In cases of suspected structural malformations of the large blood vessels of the fetal heart, a special ultrasound examination of the fetal heart is recommended to further confirm the diagnosis. If a simple precocious heart disease can be completely cured by treatment after birth, such a pregnant woman can continue the pregnancy and wait for the baby to be born for treatment. In the case of moderately difficult precardiac disease, if the baby is treated with surgery as early as possible after birth, it will not affect her life in the future. However, in more serious cases of precocious heart disease or combined with developmental malformations of other organs, the child is born with poor treatment and poor prognosis, and even if surgery is performed, the quality of life in the future is far from normal, and the obstetrician will generally recommend termination of pregnancy. This shows that whether the fetus has congenital heart disease and the type, complexity and prognosis of the heart disease are very important for whether the pregnancy should be continued or not. It is worth mentioning that many malformations do not appear in early pregnancy, but along with the progress of pregnancy, various malformations appear, and heart malformations are no exception. A single ultrasound examination of the heart alone cannot rule out all malformations, and for minor developmental abnormalities, it is not realistic to make a definitive diagnosis with a single ultrasound examination alone. As a pregnant mother, she should understand that conventional ultrasound and systemic ultrasound cannot replace special cardiac ultrasound examinations; when a clinician recommends that a fetal cardiac ultrasound examination should be performed, she should pay attention to and cooperate with the examination, and follow the doctor’s instructions for regular review at the hospital. In addition, the onset of precardiac disease is also related to genetic factors, and parents with a family history of precardiac disease are much more likely to give birth to a child with a precardiac defect. Couples with a history of bad pregnancies (e.g., history of spontaneous abortions, births of deformed children) or couples with hereditary diseases in the family (even if both spouses are normal, but there are patients with hereditary diseases in the immediate family) need to undergo detailed genetic eugenics tests (genetic, chromosomal, immunological, endocrine, etc.) before preparing for pregnancy and, based on the results, conceive under the guidance of a doctor. Special reminder that due to the lack of effective prevention methods for precocious heart disease, half of the children with untreated precocious heart disease die by the age of one and 2/3 by the age of two. Therefore, prenatal screening of pregnant women is a gateway to prevent the birth of children with severe precocious heart disease, and early detection, diagnosis and treatment are key to reducing the natural mortality rate of the disease.