Not having a 4D ultrasound during pregnancy usually has no effect, but a general ultrasound must be done. This is because at least one grand mal examination must be done during pregnancy to rule out major fetal malformations. If the doctor is good enough, even 2D ultrasound can detect most of the malformations. The difference between ultrasound of different dimensions is as follows: 1. 2D ultrasound: flat image, traditional ultrasound teratology examination, its image shows the flat image of organs or structures, this flat image can initially judge whether the fetus has malformations; 2. 3D ultrasound: three-dimensional static image, on the basis of 2D ultrasound increase the fetal surface imaging function, present three-dimensional image, judge some obvious appearance of the fetus malformations; 3. The ultrasound examination of the fetus can show the color, face and the development of each organ in three dimensions. 2D ultrasound and 3D ultrasound only show a certain surface of human organs, which can perform detoxification of the fetus’ body structure from inside to outside and screen out major malformations, such as anencephaly and severe open spina bifida. 4D ultrasound is a multi-angle and multi-directional screening of the fetus’ body structure, and can screen out some rare anomalies or minor anomalies, such as polydactyly, minor cleft lip, etc. All in all, the main thing is to have a good ultrasound examination during pregnancy, but it is not necessarily necessary to do 4D ultrasound, and it is also necessary to take into account the doctor’s requirements and your own financial situation. Of course, if you have the conditions, it is better to do 4D ultrasound, the relative results are more accurate.