Abdominal circumference is the measurement of the circumference of the abdomen under color ultrasound, according to the plane where the fetal liver and stomach are located. A large fetal abdominal circumference has little to do with holding urine and is mainly indicative of the development of the abdominal organs. At 37-40 weeks of pregnancy, the abdominal circumference should be between 330-370 mm, 10-15 mm larger than the head circumference. large fetal abdominal circumference may be caused by other factors, such as overnutrition, abdominal organ malformation, abdominal cleft, gestational diabetes, etc. When the abdominal circumference alone increases without combining with organ structural abnormalities, it is usually caused by excess nutrition, such as excessive energy intake by the mother during pregnancy, which may make the fetus too large and lead to labor difficulties and aggravated birth injuries. In this case, pregnant women need to adjust their dietary structure reasonably and exercise regularly, such as yoga and slow walking. When a pregnant woman has gestational diabetes, her blood sugar level is high and the fetus absorbs too much sugar, it will also develop too large and increase the abdominal circumference, so she needs to control her blood sugar, she can adjust her lifestyle first, and if necessary, she can use insulin treatment under the guidance of a doctor. If the fetus has a large abdominal circumference caused by abdominal organ malformation, abdominal cleft, etc., it is mostly combined with chromosomal abnormalities, which can lead to mental retardation and developmental difficulties after birth, and is generally difficult to cure, and may require timely termination of pregnancy.