Obstetricians are commonly asked to give advice on whether it is suitable for women who are pregnant to fly during pregnancy. Such advice is sought because of the physiological and environmental changes associated with commercial air travel and also because of the possibility of preterm labour or an obstetric emergency developing while in flight.

If a woman is having a straightforward pregnancy, flying is not harmful to her or her baby. The safest time to fly is before 37 weeks as after this a woman could go into labour at any time. However, for women carrying uncomplicated twins, the safest time to fly is before 32 weeks.