In late pregnancy, the gradually enlarging uterus will compress the blood vessels and chest cavity, affecting breathing and blood circulation. At this time, it will also increase the burden on the heart and lungs, easily causing the symptoms of hypoxia, which can be relieved by appropriate oxygen intake. However, it is not possible to inhale oxygen for a long time, as it may affect the development of the fetal retina and may cause glaucoma. You can inhale oxygen for half an hour or less every day, or longer if the symptoms are more serious. The concentration of oxygen should not be too high, if you do not pay attention, it will also lead to high concentration of blood oxygen content, which will affect the internal environment of the body, you need to control the flow rate and the concentration of oxygen, it is best to properly inhale oxygen under the guidance of a specialist.