Fetal heart ultrasound during pregnancy can check whether there is any abnormality in the fetal heart structure, whether the heart functions normally, especially whether the fetus has any congenital heart disease. However, it is not completely accurate and needs to be clearly diagnosed after birth. First of all, fetal heart ultrasound can find out whether there is any abnormality in the fetal heart structure, observe whether the right and left atria, right and left ventricles and heart valves are normal, and whether the ductus arteriosus is closed or not. Secondly, it can assess the alignment of the large blood vessels of the heart as well as the direction and speed of blood flow. In addition, fetal heart function can also be assessed to evaluate whether there is heart failure. If any abnormalities of the fetal heart are detected during the fetal heart ultrasound during pregnancy, further examination should be carried out in time, and the doctor will give the correct treatment according to the situation.