There are several reasons for the unclear display of the four chambers of the heart: first, the ultrasound machine is not clear enough, so the ultrasound will only see the four chambers, but the display is not clear, similar to the state of four chambers of adhesion or be mistaken for incomplete development, it is recommended to change to a better hospital to do the 4D ultrasound. Secondly, it is because 3D ultrasound does not have the three-dimensional dimension of 4D, that’s why the situation is not clear. In addition, it is necessary to do 4D ultrasound when the fetus is 6 months old, and this simple method to exclude fetal malformation is also a must for maternity checkup. Thirdly, due to congenital underdevelopment, the fetus itself does have the possibility of malformation, it is recommended to do amniocentesis to detect fetal DNA, and if necessary, perform induction of labor to terminate the pregnancy.