4D is generally not harmful to the baby. Four-dimensional is a kind of ultrasound examination, there is no radiation of light waves, rays and electromagnetic waves, it can observe the various organs of the fetus, clarify whether there is any congenital developmental abnormality, and also determine the growth and development of the fetus in the womb. 4D ultrasound can also rule out the presence of harelip on the fetus’ face and the baby’s umbilical cord around the neck. Four-dimensional examination uses the principle of ultrasound, there is no harm to the fetus. Clinically, there are many pregnant women who worry that the 4D ultrasound examination will take too long and cause some harm to the baby, which is a wrong concept. Pregnant women need to carry out the ultrasound examination reasonably under the guidance of the doctor without worrying about damaging the fetus.