Whether or not a pregnant woman can fly should be treated differently between individuals. For pregnant women with medical comorbidities during pregnancy and early and late pregnancy, air travel is not recommended because most common obstetric emergencies tend to occur in early and late pregnancy. If you must fly, you should consider the length of the flight. Because the environment in the cabin is likely to cause an increase in heart rate and blood pressure, and there is limited aerobic space, prolonged air travel is likely to cause lower extremity edema or venous thrombosis, and some measures can be taken to prevent venous thrombosis, such as moving the lower extremities regularly, walking during smooth flights, and not wearing tight clothing. The seat belt should be fastened when flying, and the seat belt should be fixed in the pelvic department, i.e. between the protruding lower part of the abdomen and the pubic bone. If the pregnant woman does not have any obstetric or medical comorbidities after pregnancy, there are no obvious abnormalities in the pregnancy process itself, and the fetus is developing well in the uterine cavity, she can fly during pregnancy. If the pregnancy process is not normal during pregnancy, there are obvious symptoms of abdominal pain or abnormal vaginal bleeding, or if the pregnant woman herself suffers from serious illnesses such as high blood pressure or heart disease, she is not suitable to fly. Many airlines allow pregnant women under 36 weeks gestation to fly, but there are exceptions. Therefore pregnant women who can fly should consult the relevant airline when preparing to travel by air.