Is it better to do 3D or 4D

The contents of three-dimensional and four-dimensional examinations are the same, and there is no excessive difference; but four-dimensional examination can observe whether the fetal motor nerves are normal, while three-dimensional examination cannot; at the same time, the state of the fetus presented by three-dimensional examination is relatively vague; and four-dimensional is relatively clear, so four-dimensional color ultrasound is better.