Oxygen inhalation twice a day after 36 weeks of pregnancy can prevent intrauterine hypoxia and generally will not affect the health of the fetus. However, pregnant women should take oxygen under the standardized guidance of doctors to avoid overdose of oxygen. The main purpose of oxygen intake during pregnancy is to prevent hypoxia from affecting embryonic development, which can reduce the risk of fetal arrest, and the process of oxygen intake will not affect embryonic development, and will not cause malformation. If 36 weeks pregnant observed more frequent fetal movement, should consider the possibility of hypoxia, this situation can be monitored through the fetal heart to understand the situation, to determine the intrauterine hypoxia, we must timely inhalation of oxygen, so as to avoid the embryo due to insufficient oxygen and cause fetal arrest. However, pregnant women must be under the guidance of a professional physician, but also need to grasp the flow of oxygen and time. After oxygen inhalation, you need to do fetal heart rate monitoring to observe the changes in fetal heart rate, and then adjust the amount of oxygen inhalation according to the results of the examination, as well as the concentration of oxygen inhalation.