4D ultrasound provides applications in obstetrics, gynecology, urology, pediatrics, etc. It can observe the dynamic operation of organs in the human body in real time, and is mainly used clinically to check whether there are abnormalities in the development of various organs of the fetus, as well as to exclude fetal developmental malformations, and can provide accurate scientific basis for early diagnosis of fetal congenital body surface malformations and congenital heart diseases. 1. brain malformations: it can exclude anencephaly, hydrocephalus, spina bifida and cerebrospinal bulge and other brain malformations. 2. 2.Facial anomalies: focus on observing whether the fetal eyes and orbits are equal in size and roundness and measuring the distance between the eyes, observing in detail the soft palate and hard palate, whether the curve of the upper lip is continuous or interrupted, and mainly screening for harelip anomalies. 3.Spinal anomalies: check whether the spine is developing normally and whether there are curved or interrupted parts and other anomalies. 4.Heart anomalies. The examination can be performed around 30 weeks to rule out fetal heart malformations, such as congenital heart disease, four heart chambers, etc. 5, urinary system malformations: 4D ultrasound can observe whether there are problems with the development of the fetal urinary system. 6, abnormal internal organ development: abdominal abnormalities, stomach abnormalities and intestinal abnormalities can be checked, such as umbilical intestinal bulge, intestinal atresia, giant intestinal colon, as well as the presence of hydronephrosis, renal agenesis, polycystic kidney and bladder malformations. and bladder malformation. Pregnant women are generally recommended to have 4D ultrasound at 22-26 weeks of pregnancy, and organ malformation can be performed at 21 weeks, and it is clearer to exclude fetal heart malformation around 30 weeks. You don’t need to fast before the 4D ultrasound, eat normally and rest well to ensure that you have plenty of energy for the next day’s delivery.