4D ultrasound examination is actually a special form of ultrasound examination, which is a non-invasive examination method, and there is no obvious pain and discomfort for pregnant women during the examination. When carrying out 4D ultrasound examination: 1, master the examination time of 4D ultrasound, generally in 20-28 weeks of pregnancy directly; 2, thinking ultrasound examination generally need to be booked 2-4 weeks in advance; 3, 4D ultrasound examination does not need fasting, also do not need to hold urine; 4, 4D ultrasound examination process takes a long time, pregnant women should pay attention to relax, do not be nervous; 5, 4D ultrasound examination is a dynamic examination The process is a dynamic examination. The images seen during the examination can be burned into a CD, and pregnant women and their families can observe the development and activities of the fetus in the uterine cavity through the CD.