Four-dimensional ultrasound cardiac septal defects are problematic atrial septal defects, ventricular septal defects, etc., indicating the presence of congenital heart disease in the fetus, the defects are less severe when you can choose the child to be born for surgical treatment, and the defects are more severe when you need to consider termination of pregnancy. Four-dimensional ultrasound examination is the presence of cardiac septal defects, you need to carry out a fetal heart ultrasound examination, if the fetus does exist in this case, to determine the severity of atrial septal defects or ventricular septal defects. If the atrial septal defect or ventricular septal defect is mild and will not affect the blood supply of the fetus in a short period of time, then consideration can be given to continuing the pregnancy and waiting for the fetus to be born before proceeding with surgical treatment. If the condition of atrial septal defect or ventricular septal defect in the fetal heart is more severe, it can lead to changes in the blood flow of the fetus, resulting in cyanosis and insufficient oxygen supply, and death may occur. Prompt termination of pregnancy is required. Pregnant women are advised to have timely pregnancy checkups to determine whether the growth and development of the fetus is normal or not. If there are any problems, they need to seek medical treatment in time and take reasonable methods to deal with them under the guidance of doctors.