The oxygen inhaled by pregnant women is not pure oxygen, but mixed oxygen. During the whole process of pregnancy, due to the relatively heavy burden of various organs of the body, coupled with the gradual development and enlargement of the fetus, it is easy to appear hypoxia phenomenon, which will jeopardize the health of the fetus, when there is a phenomenon of hypoxia during pregnancy and indications, oxygen can be properly inhaled. Pregnant women should pay attention to the time, concentration and flow of oxygen inhalation, generally inhale mixed oxygen, can not use pure oxygen, prolonged inhalation of pure oxygen will lead to too high a concentration of oxygen in the blood, resulting in oxygen toxicity, which will cause certain damage and harm to the retina of the fetus. Can not be arbitrary oxygen during pregnancy, such as oxygen indications recommended under the guidance of a doctor for low-flow oxygen, oxygen time in about half an hour, according to the specific circumstances of the correct oxygen, can not breathe pure oxygen. Pregnant women during pregnancy should pay attention to do a good job of prenatal checkups, actively listen to the advice of professional doctors to do a good job of comprehensive care and health care, pay attention to more rest, at the same time should be relaxed, to avoid nervousness, anxiety, there is any discomfort should be timely to the hospital, by the doctor to clarify the diagnosis and cooperate with the doctor to deal with the symptoms.