Flying in pregnancy can have adverse effects and is usually not recommended in early pregnancy, before the weekend of the 13th week of pregnancy, and in late pregnancy, after the 28th week of pregnancy. In early pregnancy, the embryo has just been laid and the connection between the fetus and the mother is not secure, making it prone to miscarriage. During the takeoff and landing of the plane, there is usually a gastrointestinal reaction due to the bumpy airflow, and pregnant women have early pregnancy reaction, which is more likely to induce vomiting; in the late pregnancy, the change of air pressure at high altitude may also lead to uterine contraction, causing premature rupture of fetal membranes and preterm labor. In addition, when pregnant women fly, they are in a small space for a long time, so their blood circulation is slow and they are in a state of high coagulation, which increases the chance of venous thrombosis in the lower limbs. Therefore, pregnant women need to have a maternity checkup 2 weeks before flying to understand their own situation. When flying, it is necessary to fasten the seat belt to prevent falls and collisions, massage the leg muscles when necessary and walk appropriately to improve blood circulation and reduce the chances of venous thrombosis.