It is useful for pregnant women to do four-dimensional ultrasound, and the main effects are as follows: first, through four-dimensional ultrasound examination can judge whether the fetus has malformation problems, such as whether there are fetal facial malformations, neurological malformations and other various problems, if the fetus in the process of development, there are cleft lip and palate, anencephaly, hydrocephalus, and other various conditions; second, it can judge whether there is a Digestive system abnormalities, such as visceral ectopia, intestinal atresia or megacolon and other various problems, but also can judge whether there is hydronephrosis, urethral obstruction, etc.; third, can be judged by four-dimensional ultrasound examination whether there are other malformations, such as short limb deformity, tetralogy of limbs, internal cavities and other problems, but also can judge whether there is amniotic fluid is too much or too little, four-dimensional ultrasound examination can intuitively see the development of fetal The four-dimensional color ultrasound examination can visualize the development of the fetus.