Question: How can I stay comfortable during a plane flight?

Answer: There are a number of things you can do. Request a seat in the middle of the plane over the wing for the smoothest ride, or a bulkhead seat for more legroom. In either case, reserve a seat on the aisle so you can get to the bathroom easily and get up to walk and stretch.

Sitting anywhere for long periods of time can make your feet and ankles swell and your legs cramp. Take off your shoes and elevate your legs by resting your feet on your carry-on luggage under the seat in front of you. If the seat next to you is empty, put your feet up on it. Since pregnancy makes you more susceptible to thrombosis (the formation of blood clots) and varicose veins, keep your blood circulating by strolling the aisle every hour and doing some simple stretches every half hour. Try this: When seated, extend your leg, heel first, and gently point and flex your foot to stretch your calf muscles. When seated, rotate your ankles and wiggle your toes. Get up once every hour or so to walk around, but make sure you sit down as soon as there's a whiff of air turbulence.

Always keep your seat belt fastened under your belly and low on your hips while seated. And drink plenty of fluids, especially water, to stave off the dehydrating effects of dry cabin air. Caffeine can act as a mild diuretic, so it's best to avoid coffee, tea, and certain soft drinks before and during the flight. And beware of consuming gas-producing meals or drinks before takeoff. The trapped gas from foods such as cabbage and beans expands at higher altitude, making for an uncomfortable trip.

Wear whatever makes you comfortable. Beyond that, it's best to wear a dress or separates, such as a skirt or pants with a top (rather than a jumpsuit or overalls), to accommodate frequent trips to the bathroom. Stick to outfits with few or no fasteners — that helps speed up your pit stops. Layer your clothing to cope with sudden temperature changes. Since your feet will probably swell, wear comfortable shoes with expandable elastic panels, laces, or adjustable straps. Bring a thick pair of socks or some comfy slippers to wear around the cabin if you take your shoes off. If you're prone to varicose veins or swelling, wear maternity support panty hose, which relieve swelling and aching in your legs by strategically compressing your veins to keep blood flowing.

You can fly on commercial airlines without restriction during your first and second trimesters, but during your third trimester you may run into some restrictions.

All airlines recommend that you consult your doctor before traveling at any point in your pregnancy. Play it safe by getting a "permission-to-travel" letter from your healthcare provider.

You won't – and shouldn't – get one if your pregnancy is considered high-risk.

Take your due date into consideration for the return trip, too. And before you plan a cross-country or international flight, remember how you'll feel squeezed into a seat for hours.

Alaska Airlines/Horizon Air www.alaskaair.com

(800) 252-7522

Domestic:

No restrictions, but passengers are advised to consult a doctor

International:

No restrictions, but passengers are advised to consult a doctor

American Airlines www.aa.com

(800) 433-7300

Domestic:

• Doctor's letter required if traveling within four weeks of delivery date.
• Travel within seven days before due date or after delivery requires doctor's letter plus clearance by AA special-assistance coordinator.
• Restrictions based on honor policy.

International:

• Doctor's letter required if traveling within 30 days of due date, signed within 48 hours of travel.
• Travel within ten days before due date or after delivery requires doctor's letter plus clearance by AA special-assistance coordinator.

Continental Airlines www.continental.com

(800) 523-3273 (domestic)

(800) 231-0856 (international)

Domestic:

• Passengers advised to consult a doctor if traveling beyond the "seventh month."
• Doctor's letter required if traveling within seven days of due date.
• Travel prohibited if signs of labor exist.

International:

Same restrictions apply.

Delta Airlines www.delta.com

(800) 221-1212

Domestic:

No restrictions, but passengers are advised to consult a doctor.

International:

No restrictions, but passengers are advised to consult a doctor.

Frontier Airlines www.frontierairlines.com

(800) 432-1359

Domestic:
No restrictions, but passengers are advised to consult a doctor.

International:
No restrictions, but passengers are advised to consult a doctor.

Hawaiian Airlines www.hawaiianair.com

(800) 367-5320

Domestic:

• Doctor's letter required for travel within seven days of due date, signed within 72 hours of travel, indicating 1) due date and 2) that based on medical examination, travel doesn't pose a health risk.
• Airline may require examination by medical personnel if passenger doesn't appear fit to fly on day of departure.
• Restrictions based on honor policy.

International:

Same restrictions apply.

JetBlue Airways www.jetblue.com

(800) 538-2583

Domestic:

• Doctor's letter required for travel within seven days of due date, signed within 72 hours of travel, indicating 1) due date and 2) that based on medical examination, travel doesn't pose a health risk.
• All travel must be scheduled for completion by due date.
• Restrictions based on honor policy.

International:

Same restrictions apply.

Southwest Airlines www.iflyswa.com

(800) 435-9792

Domestic:

• No restrictions, but airline strongly recommends against flying at 39 weeks or later.
• Pregnant women may be asked not to sit in the emergency exit row.

International:

Southwest has no international flights.

Spirit Airlines www.spirit.com

(800) 772-7117

Domestic:

• In last month of pregnancy, you need a doctor's letter signed within 72 hours of travel, indicating that, based on a medical examination, travel on specified date doesn't pose a health risk.
• Restrictions based on honor policy.
• Travel prohibited if signs of labor exist.

International:

Same restrictions apply.

United Airlines www.united.com

(800) 241-6522

Domestic:

• No restrictions during first eight months.
• In last month of pregnancy, you need a doctor's letter signed within 24 to 72 hours of travel, indicating 1) due date, 2) departure and arrival destinations and dates, and 3) that travel doesn't pose a health risk.
• Restrictions based on honor policy.

International:

Same restrictions apply.

US Airways www.usairways.com

(800) 428-4322

Domestic:

• Doctor's letter required for travel within seven days of due date, signed within 72 hours of travel, indicating that travel. doesn't pose a health risk
• Restrictions based on honor policy.

International:

Same restrictions apply.

Virgin America/Virgin Atlantic www.virginamerica.com and www.virgin-atlantic.com

(877) 359-8474

Domestic:

• Doctor's letter required if traveling within seven days of due date, indicating that travel doesn't pose a health risk; for round-trip travel, letter must indicate you'll be fit for return trip, too.
• Restrictions based on honor policy.

International:

• No restrictions through 27 weeks.
• Travel between 28 and 36 weeks requires pregnancy info form to confirm due date and that pregnancy is uncomplicated.
• All travel must be completed by end of 36 weeks.

Other Airlines do check their appropriate websites for more guidelines.

My family has planned a trip to Florida when I'll be around seven months pregnant. Is it safe to fly this late in pregnancy?

Although it can be perfectly safe to fly during much of your third trimester (up to 36 weeks), be sure to discuss your trip plans with your healthcare provider before you book your flight. In certain high-risk cases, your healthcare provider may advise you to stay close to home throughout your pregnancy. If you're carrying twins or multiples, have diabetes or high blood pressure, have placental abnormalities or vaginal bleeding, are under observation for preterm labor, or have a history of forming blood clots (including prior to pregnancy), the smart choice may be to postpone your travels.

Even if you're enjoying an uncomplicated pregnancy, it's best to avoid flying during your final month, when you're more likely to go into labor. Many airlines, in fact, won't let women on board who are due to deliver within seven or sometimes 30 days of the flight (they don't want you to deliver while in the air!). Be sure to carry a note from your healthcare provider stating your expected due date to avoid disputes at the boarding gate. However, each airline has different rules about when and whether it will allow you to fly. And don't forget to take into account how far along you'll be on the return flight.

Before you leave, have your healthcare provider refer you to a midwife or obstetrician at your destination in case you need medical attention during your vacation. Carry a complete list of emergency contacts and, if you're in your second or third trimester, carry a copy of your prenatal chart as well. A prenatal chart should include your age, due date, last menstrual period, number and outcomes of prior pregnancies, risk factors for disease, pregnancy-related lab tests and ultrasounds, medical and surgical history, and a flow sheet of vital signs taken at each visit.

If you're healthy and have no obstetric problems, you and your baby should have no trouble in the pressurized cabin of a commercial airliner. The best thing to do is to make yourself as comfortable as you can during the flight. Request a seat in the middle of the plane over the wing for the smoothest ride, or a bulkhead seat for more legroom.

In either case, reserve a seat on the aisle so you can get to the bathroom easily and get up to walk and stretch. Pregnant women who are immobile for long periods of time are at increased risk for developing blood clots, so be sure to walk around the cabin at least once an hour. You should also stretch and flex your feet and legs in your seat every 30 minutes. Wearing maternity support panty hose (not knee highs) helps keep the blood moving in your legs and decreases your risk for clots and swollen feet.

When seated, keep your seatbelt fastened under your belly and low on your hips at all times. Also, drink plenty of fluids, especially water, to stave off the dehydrating effects of dry cabin air. Caffeine acts as a diuretic, so it's best to avoid coffee, tea, and caffeinated soft drinks before and during the flight. And beware of gas-producing meals or drinks before takeoff. The trapped gas from foods such as cabbage and beans expands at higher altitude, making for an uncomfortable trip.

I've heard that airplane passengers are exposed to radiation. Will this harm my unborn baby?

Natan Haratz-Rubinstein ob-gyn

"Radiation" is a terrifying word to expectant mothers, so you'll be glad to hear that plane travel is generally safe in this regard.

Whether we're on land or in the air, we're exposed every day to cosmic ionizing radiation, which emanates from the sun and other stars. On the ground, the Earth's atmosphere offers some protection from the radiation. At high altitudes, the air is thinner and radiation levels are somewhat higher, but they're not usually high enough to be of concern to the occasional traveler.

Radiation levels can be a lot higher, though, during solar flares — bursts of electromagnetic radiation caused by disturbances in the sun's atmosphere. Fortunately, solar flares are rare and last only a short while.

The National Oceanic and Atmospheric Administration posts solar radiation storm alerts on its Web site. Some experts recommend that pregnant women check the site before flying and consider postponing their trip a day or two if a storm is forecast.

Some experts think that cosmic radiation could pose a small risk to flight crews and frequent fliers, and there is ongoing research to assess these risks. In some countries, pregnant crew members are reassigned to low-altitude flights or given jobs on the ground for the duration of their pregnancies. But for infrequent air travelers, pregnant or not, the risk from cosmic ionizing radiation under normal solar conditions is considered negligible.

The Federal Aviation Administration (FAA) requires all commercial airlines and many noncommercial planes to maintain a standard level of cabin pressure (kept at the equivalent of 5,000 to 8,000 feet, the altitude of Denver and other Rocky Mountain communities). If you're a healthy woman with no serious medical problems, you and your baby should have no trouble in a pressurized cabin.

However, because the air pressure in the cabin is less than at lower altitudes, your heart rate and blood pressure will increase to enable you to take in the oxygen you need. If you have severe anemia, sickle cell disease, a history of blood clots, or a condition called placental insufficiency, you and your baby may have trouble adapting and should avoid flying. If you have one of these conditions and must fly, you can be prescribed supplemental oxygen for use in the air. (And in case of sudden loss of cabin pressure during a flight, all commercial airliners are equipped with oxygen masks that drop down automatically.)

Flying in unpressurized small planes is a different matter. If you're cruising at 10,000 feet, for example, that's just like standing atop a 10,000-foot mountain — almost 2 miles high. Your body will have to work harder to supply you and your baby with sufficient oxygen, so it's probably wise to avoid unpressurized planes while you're pregnant.

Reviewed by the BabyCenter Medical Advisory Board

If you have a normal, healthy pregnancy, it can be perfectly safe to fly during most of it. Discuss your trip plans with your doctor or midwife, however, before booking your flight. In certain high-risk cases, your healthcare provider may advise you to stay close to home throughout your pregnancy.

You may find that your second trimester — weeks 14 to 27 — is a perfect time to fly. Once you're past the first trimester, in all likelihood your morning sickness will be behind you, your energy levels will be higher, and your chances of miscarriage will be low. However, you shouldn't travel after 36 weeks.

Before you leave, have your prenatal caregiver refer you to an obstetrician or midwife at your destination in case you need medical attention during your vacation. If you'll be traveling during your second or third trimester, it's a good idea to carry a copy of your prenatal chart. The chart should include your age, the date of your last menstrual period, your due date, the number and outcomes of any prior pregnancies, your risk factors for disease, pregnancy-related lab tests and ultrasounds, medical and surgical history, and a flow sheet of vital signs taken at each visit.