4D ultrasound examination is the most advanced ultrasound examination technology at present. Because of the advanced instrumentation and equipment, there is no effect on the fetus and the pregnant woman, so generally the 4D ultrasound examination is performed at 22-28 weeks of fetal life, and it is generally best to do it at 24 weeks to screen for fetal heart and fetal malformations. It can rule out congenital heart disease and can screen the fetal face, spine, limbs, chest and abdomen, including liver, spleen, gallbladder, pancreas, both kidneys and bladder malformations.