Abdominal circumference is the measurement of the circumference of the abdomen under color ultrasound, according to the plane where the liver and stomach of the fetus 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, which is 10-15 mm larger than the head circumference. large fetal abdominal circumference may be caused by other factors, such as over-nutrition, malformation of the abdominal organs, gastroschisis, and gestational diabetes. When the abdominal circumference increases alone without combining with organ structure abnormality, it is usually caused by over-nutrition. For example, if the mother consumes too much energy during pregnancy, it may make the fetus too large, which may lead to labor difficulties and aggravate birth injury. This situation requires pregnant women to rationalize their dietary structure and exercise regularly, such as yoga and slow walking. When a pregnant woman suffers from gestational diabetes mellitus, her blood glucose level is high and the fetus absorbs too much sugar, which may also lead to overgrowth and increased abdominal circumference. It is necessary to control the pregnant woman’s blood glucose, and she can adjust her lifestyle first, and use insulin therapy under the guidance of her doctor if necessary. In case of abdominal organ malformation, abdominal cleft and other causes of fetal abdominal circumference, mostly combined with chromosomal abnormalities, which can lead to postnatal mental retardation and developmental difficulties, it is generally difficult to cure, and may require timely termination of pregnancy.