Whether or not 24-week intestinal dilatation of 9mm is serious mainly depends on whether or not the fetus is pathologically dilated. If the dilatation disappears or decreases, the dilatation is physiological and there is no need to be overly concerned. If the dilatation of 9mm at 24 weeks is due to pathologic causes, such as fetal lower gastrointestinal obstruction, regular follow-up ultrasound is needed to observe the degree of dilatation, and chromosomal anomalies need to be checked for risk. Relevant treatment should be carried out under the guidance of specialized obstetricians and neonatologists. Pregnant women should pay attention to regular obstetric checkups during pregnancy, so that problems can be detected and dealt with at any time.