Four-dimensional also do heart ultrasound because four-dimensional ultrasound is mainly to check the fetal limbs, face, face, internal organs and so on to carry out the examination, but the examination of a certain organ of the fetus has certain limitations, so to carry out the heart ultrasound examination. Fetal heart ultrasound is mainly to check the fetal heart structure, heart function and blood flow, etc. And it is also the preferred examination method to diagnose fetal congenital heart disease. Generally, fetal heart ultrasound can be performed at 22~28 weeks of pregnancy. Moreover, the probes and examination methods used for 4D ultrasound and fetal heart examination are different and cannot replace each other. Through prenatal fetal heart examination, it may be possible to judge simple congenital heart disease, which is conducive to giving timely treatment after birth; it may also be possible to recognize complex congenital heart disease at an early stage and terminate the pregnancy in time. Pregnant mothers should be on time for obstetric checkups during pregnancy, and timely diagnosis and treatment when abnormalities are detected.