The difference between 3D and 4D color ultrasound is that 4D provides a dynamic, three-dimensional view of all fetal structures. Both 3D and 4D ultrasound can be used to screen for fetal structural abnormalities during pregnancy. There is also no essential difference in their accuracy. The 4D ultrasound can be done during the 22-28 weeks of pregnancy to screen the fetus for defects and to understand the growth and development of the fetus. Compared with 3D ultrasound, 4D ultrasound can provide a dynamic, three-dimensional view of the fetus to see if the structures are well developed and if there are any abnormalities. During pregnancy, you should follow the doctor’s instructions and have an obstetric examination on time to keep track of the development of the fetus in all aspects. Maintain a stable state of mind, don’t be nervous, don’t be irritable, and so on. If you feel unwell during pregnancy, go to the obstetrics and gynecology department in time.