Women are prone to fetal hypoxia in the second trimester, so it is recommended that oxygen be administered, with the oxygen meter flow turned up to 2 or 3. During pregnancy, doctors should evaluate the fetal well-being through various auxiliary examination methods to help the fetus out of danger early, such as listening to the fetal heartbeat and doing fetal heart monitoring after 36 weeks are the more common methods. When the fetal heart rate is lower than 110 beats/min or higher than 160 beats/min, and the fetal monitoring score is lower than 7, it means the fetus is hypoxic, and once it indicates the fetus is hypoxic, it needs oxygen inhalation to correct it. It is recommended to give the pregnant woman low-flow oxygen inhalation for 30 minutes immediately, and the flow rate of the oxygen meter can be turned on to 2 or 3, which can correct the hypoxia caused by momentary factors and improve the tolerance of the fetal organism, and if it is a factor that cannot be corrected, oxygen inhalation can also win time to save the fetus. If a large amount of high concentration of oxygen for a long time is likely to lead to fetal retinal detachment, so oxygen inhalation must be low-flow oxygen and not recommended for more than 30 minutes at a time, and must avoid high-flow long-term oxygen inhalation. If the fetal movement increases or decreases significantly, it may indicate fetal hypoxia.