Commercial air travel poses no special risks to a healthy pregnant woman or her fetus. The American College of Obstetricians and Gynecologists (ACOG) states that women with healthy, single pregnancies can fly safely up to 36 weeks' gestation. The lowered cabin pressures (kept at the equivalent of 1,524-2,438 meters [5,000-8,000 feet]) affect fetal oxygenation minimally because of the favorable fetal hemoglobin-oxygen dynamics. If required for some medical indications, supplemental oxygen should be arranged in advance (see Chapter 7). Severe anemia, sickle-cell disease or trait, or history of thrombophlebitis are relative contraindications to flying. Pregnant women with placental abnormalities or risks for premature labor should avoid air travel. Each airline has policies regarding pregnancy and flying; it is always safest to check with the airline when booking reservations, because some will require medical forms to be completed. Domestic travel is usually permitted until the pregnant traveler is in week 36 of gestation, and international travel may be permitted until weeks 32-35, depending on the airline. A pregnant woman should be advised always to carry documentation stating the expected day of delivery.

Airport security radiation exposure is minimal for pregnant women and has not been linked to an increase in adverse outcomes for unborn children to date. However, because of early reports of a possible association of radiation exposure during pregnancy and subsequent increased risk of childhood leukemia and cancer, a pregnant passenger may request a hand or wand search rather than being exposed to the radiation of the airport security machines.

An aisle seat at the bulkhead will provide the most space and comfort, but a seat over the wing in the midplane region will give the smoothest ride. A pregnant woman should be advised to walk every half hour during a smooth flight and flex and extend her ankles frequently to prevent phlebitis. The safety belt should always be fastened at the pelvic level. Dehydration can lead to decreased placental blood flow and hemoconcentration, increasing risk of thrombosis. Thus, pregnant women should drink plenty of fluids during flights.

For pregnant flight attendants and pilots, working air travel is restricted by most airlines by 20 weeks gestation.