The most common cause of belly itching at 37 weeks of pregnancy is caused by maternal cholestasis syndrome. But there is also a small number of patients will appear normal physiological reaction, in the middle and late pregnancy, due to the fetus and uterus enlargement, resulting in muscle fibers or belly fibers slightly broken, the appearance of itching during the stretch marks, or have dermatitis when the appearance of belly itching, all of these are possible. Need to pay attention to observe and determine, it is best to observe the belly during this period there is no yellowing phenomenon, but also observe the pregnant woman to see if there is a loss of appetite, anorexia symptoms. If there are symptoms, it is best to check the serum total bile acid value of pregnant women, if the serum total bile acid value is elevated, indicating that it is caused by cholestasis syndrome, should be timely treatment.