After a pregnant woman has had a 3D, she can consider whether to have a 4D in conjunction with the doctor’s results from the 3D. Three-dimensional (three-dimensional color ultrasound) belongs to static color ultrasound, four-dimensional (four-dimensional color ultrasound) belongs to dynamic color ultrasound, compared to three-dimensional color ultrasound, four-dimensional color ultrasound will be more clear, which is mainly used for some malformation examination, for some systematic malformation diagnosis will be more clear, after doing three-dimensional color ultrasound, you can combine with the doctor’s results from three-dimensional color ultrasound, and then consider whether you need to do four-dimensional color ultrasound. Clinically, it is recommended that pregnant women go to the hospital for regular checkups and take targeted measures according to the results of the checkups. Usually around 22-28 weeks of pregnancy, pregnant women are recommended to go to the hospital for 3D ultrasound and 4D ultrasound because at this time, all parts of the fetus’s organs can be clearly displayed, and the growth and development of the fetus can be observed, with a high degree of diagnostic accuracy.