Three-dimensional or four-dimensional ultrasound examination is very necessary, three-dimensional or four-dimensional ultrasound examination is currently the most advanced examination technology, advanced instrumentation, high clarity, high resolution, small structures can be distinguished clearly. Three-dimensional or four-dimensional ultrasound can rule out congenital malformations, which is very meaningful for the birth of a healthy baby. The doctor who performs 3D or 4D ultrasound is a systematically trained sonographer who is qualified to perform systematic screening. 3D or 4D ultrasound can rule out congenital cleft lip, cleft palate, spinal and limb developmental malformations, congenital brain malformations, abdominal organs including liver, spleen, bile, pancreas, both kidneys, bladder for malformations; and rule out cardiovascular malformations, such as congenital cardiac malformations such as transposition of the heart, univentricularity, monoventricularity, hypoplasia of the right heart, transposition of the great arteries, tetralogy of Fallot and so on.