Generally, commercial air travel before week 36 of pregnancy is considered safe if you have a healthy pregnancy. Still, if you're pregnant, check with your health care provider before you fly.

Your health care provider might caution against air travel if you're experiencing pregnancy complications that might be worsened by air travel or require emergency care. The duration of the flight also should be considered. Similarly, your health care provider and many airlines might restrict travel after 36 weeks of pregnancy.

If your health care provider approves air travel and your plans are flexible, the best time to fly might be during your second trimester. This is when the risks of common pregnancy emergencies are the lowest.

When you fly:

• Check the airline's policy. Guidelines for pregnant women might vary by carrier and destination.
• Buckle up. During the trip, fasten the lap belt under your abdomen.
• Promote circulation. Take occasional walks up and down the aisle. If you must remain seated, flex and extend your ankles periodically. Also, avoid wearing tightfitting clothing. Use of compression stockings might help.
• Drink plenty of fluids. Low humidity in the cabin can lead to dehydration.
• Avoid gassy foods and drinks preflight. Entrapped gases expand at altitude, which can cause discomfort. Examples include broccoli and carbonated drinks.
• Make a contingency plan. Consider how, if necessary, you'll obtain obstetric care during your trip.

Radiation exposure associated with air travel at high altitudes isn't thought to be problematic for most who fly during pregnancy. However, pilots, flight attendants and other frequent fliers might be exposed to a level of cosmic radiation that raises questions during pregnancy. If you must fly frequently during your pregnancy, discuss it with your health care provider. He or she might recommend limiting your total flight time during pregnancy.