Appropriate oxygen inhalation will not affect the fetus when the pregnant woman has symptoms of hypoxia, but it will have an effect on the fetus if the oxygen is inhaled at high concentration and high flow rate for a long time. If the pregnant woman in the pregnancy of hypoxia discomfort or fetal hypoxia symptoms, can be under the guidance of the doctor low-flow, low-frequency oxygen inhalation, will not endanger the development and health of the fetus. However, if over-oxygenation is administered without indications for oxygen intake, the fetus will be adversely affected. Excessive oxygen intake may cause the concentration of blood oxygen content in the blood to be too high, which may result in oxygen toxicity, and may even adversely affect the development of the baby, leading to an increased chance of retinopathy. Therefore, pregnant women during pregnancy do not arbitrarily oxygen, if there are indications of oxygen can be under the guidance of the doctor low-flow oxygen, a time should not be too long oxygen, to avoid their own blind oxygen.