The examination process of 4D ultrasound: 1. You need to make an appointment for 4D ultrasound examination 2-4 weeks in advance. You should attend the clinic on time according to the appointment time and have the 4D ultrasound examination; 2. You do not need to fast or hold urine during the 4D ultrasound examination; 3, The pregnant woman should pay attention to cooperate; 6. The process of 4D ultrasound examination usually takes a long time, so pay attention to relax and don’t have too much pressure during the examination.