In addition to its great contribution to the diagnosis and research on fetal malformations, 4D ultrasound has also played an important role in other fields in recent years. In fact, in the public’s mind, 4D ultrasound is ultrasound for fetuses. What is clinically referred to as 4D ultrasound is a level III prenatal screening program for the fetus that is performed at a specific period of time, that is, between 18 and 24 weeks. There is a reason why 4D ultrasound is so important. The fetus is fully visualized at this time and most malformations can be detected. The structures inside the fetal skull, the fetal face (eyes, nose, mouth), the fetal internal organs (heart, liver, stomach, gallbladder, kidneys, bladder, etc.), and even the fetal nasal bone and the structures inside the eyes can be observed. Many surgeons in major hospitals are lamenting the fact that in recent years, due to the improvement of prenatal screening techniques, those complicated cases of congenital heart disease have dropped drastically. This fully demonstrates that prenatal screening has made a great contribution to eugenics and at the same time provides the most direct way to recognize diseases.