In late pregnancy, the increase in fetal size will lead to an increase in blood circulation, which will increase the amount of blood circulation in the heart muscle of pregnant women, resulting in chest tightness and breath-holding, so usually pay attention to not overexerting yourself and take rest in the left side position to improve the state of myocardial ischemia and hypoxia. In late pregnancy, the diaphragm moves up and presses on the lungs, resulting in a decrease in the respiratory function of the lungs, so try to avoid overexertion. In the middle and late stages of pregnancy, you can reduce myocardial ischemia and hypoxia by resting on the left side and increasing the heart beat volume to reduce the occurrence of chest tightness, and you can also improve the symptoms of breath-holding by intermittent oxygen intake for half an hour each time, twice a day, which helps to supply oxygen to the pregnant woman and the fetus.