Tightening and hardening of the stomach at 40 weeks of pregnancy is usually caused by contractions, indicating that the pregnant woman is about to go into labor, but there may also be false contractions. 40 weeks pregnant has reached the due date, at this time, the pregnant woman’s stomach is tight and hard, indicating the emergence of contractions, if the contraction is regular, gradually strengthened, and the pregnant woman feels respiratory distress relief, gastric pressure disappeared, the amount of food increased, but there is a feeling of abdominal drop waist acidity. Generally it is a sign of labor, in addition, the pregnant woman will also be gradually separated from the fetal membrane and uterine wall friction and bleeding phenomenon. However, if the pregnant woman’s stomach is tight and hard with no time pattern, and the strength is weak, it is generally false contractions. When a pregnant woman’s stomach becomes tight and hard during the 40th week of pregnancy, she should go to the hospital immediately and under the guidance of the doctor for further examination in order to make a judgment.