Occasionally, a pregnant woman takes oxygen for more than 2 hours at a time is usually not affected, but needs to be under the supervision of a doctor. During pregnancy, it is important to be on time for labor and delivery, and fetal movement counting at 28 weeks of gestation allows for self-assessment of the intrauterine status of the fetus. There is generally no effect when oxygen is administered for more than 2 hours once in a while during pregnancy, but oxygen should not be administered blindly and privately during pregnancy, especially oxygen of higher concentration, which needs to be administered under the guidance of a doctor. Pregnant women should be on time for maternity checkups, regular self-counting of fetal movement, when abnormal fetal movement, the need to go to the hospital in a timely manner, and ultrasound and fetal heart monitoring and other adequate assessment, but also to give a low-flow oxygen, rehydration, change of position, and other corrective measures, if there is no improvement in the person to be terminated in a timely manner, in order to ensure the safety of mothers and babies.