4D, or four-dimensional ultrasound, can show whether the fetus has cleft lip, cleft palate, neural tube malformation, abnormal bone development, cardiovascular malformation and other malformations. Four-dimensional ultrasound is mainly used for ultrasound examination of the fetus, which can show the color, face, and development of each organ of the fetus in three dimensions. It can see the state of the fetus in the mother’s body, and can also observe whether the fetus has any malformations, such as cleft lip, cleft palate, neural tube malformation, abnormal bone development, cardiovascular malformation, etc. It can also check the immediate state of the heart, kidney, abdomen, face, and limbs. However, it should be noted that if the pregnant woman’s abdominal wall is thicker, the position of the fetus will also affect the examination, resulting in a part of small malformations may be missed, such as polydactyly and slight cleft lip, etc. It is recommended that the examination time of 4D ultrasound is usually from 22 weeks to 26 weeks of pregnancy. During pregnancy, you should maintain a good habit of life, can be appropriate exercise, and follow the doctor’s instructions on time for maternity examination.