Air Travel During Pregnancy in the First and Second Trimesters
Women can safely fly on commercial flights during the first and second trimesters of pregnancy in the absence of obstetric or medical complications. 1, 2
Safety Profile and Timing
Uncomplicated pregnancies: Pregnant women without medical or obstetric complications can observe the same precautions for air travel as the general population and fly safely. 1, 2
Optimal timing: The second trimester is considered the safest period for air travel, as pregnant women generally feel most comfortable, and the risks of spontaneous abortion and preterm labor are lowest during this time. 3
Gestational age limits: Most airlines permit flying up to 36 weeks gestation for domestic flights and 35 weeks for international flights, meaning first and second trimester travel is well within acceptable limits. 4, 3
Physiologic Considerations
Cabin pressure and oxygenation: In-flight environmental conditions including low cabin humidity and changes in cabin pressure result in maternal adaptations that may have transient effects on the fetus, but these do not pose significant risk in healthy pregnancies. 4
Fetal hypoxia risk: Unless fetal oxygen supply is already impaired at ground level due to underlying disease, flying does not pose a risk of fetal hypoxia. 3
Radiation exposure: For most air travelers, risks to the fetus from cosmic radiation exposure are negligible during occasional flights. 1, 2
Contraindications and High-Risk Situations
Pregnant women should avoid air travel if they have:
- Significant risk for preterm labor 4
- Placental abnormalities 4
- Medical conditions that may be exacerbated by hypoxic environments (these patients require supplemental oxygen if air travel is necessary) 4
- Pre-existing medical conditions that could be complicated by flight (consultation with obstetrician required before travel) 5
Essential Safety Precautions
Seat belt use: Pregnant women must continuously use seat belts while seated, as air turbulence cannot be predicted and the risk for trauma is significant. 1, 4, 2
Thrombosis prevention measures (despite lack of hard evidence, these preventive steps are recommended):
- Use of support stockings 2
- Periodic movement of lower extremities 2
- Occasional ambulation during flight 2
- Avoidance of restrictive clothing 2
- Maintenance of adequate hydration 2
Travel Planning Considerations
Pregnant women should familiarize themselves with the healthcare system at their destination and develop an emergency plan for accessing medical care if needed. 5
Those with underlying medical conditions should only embark on long-distance travel following consultation with their obstetrician. 5