First, the big question: Is it safe? Most newborns are physiologically fit to fly, says Dr. Robert Wheeler, medical director for On Call International, a global travel and medical assistance provider. The main concern is exposure to illness.

"The safe age is pretty young – 1 to 2 weeks old is OK if the trip is really necessary," says Dr. James Sears, a pediatrician, co-author of The Baby Book: Everything You Need to Know About Your Baby from Birth to Age Two (Little, Brown and Co., 2003) and member of the Lansinoh Breastfeeding Advisory Board. However, he usually tells parents to wait until after 6 months if they can. "A harmless cold virus in an older child can cause a severe respiratory infection in a young baby," he says.Aircraft air is not as detrimental as it used to be, Dr. Wheeler says. Only 50 percent of the air inside a plane is filtered and recirculated air, mixed with 50 percent fresh air pulled in from the outside. And the air is exchanged frequently. For instance, in a normal home about half the air inside is exchanged per hour. Aircraft air is fully exchanged about 20 times per hour. "Filtered air is actually pretty clean compared to walking around in a mall," Dr. Wheeler says.

Of course, any public transportation can expose babies to illnesses – and the longer the flight, the longer the exposure. Proximity increases exposure as well, which can be both good and bad news – good news because most bugs won't travel beyond a few rows, bad news if you are sitting near someone contagious.

"It's also important to be aware that a lot of illnesses we pick up come from surfaces," Dr. Wheeler says. For instance, if a passenger with a respiratory infection coughs into his hand, then touches the restroom door, the next person to touch that door stands a chance of picking up that illness.

While babies under 3 months of age aren't grabbing for objects yet, you will be touching things – then touching your baby – which makes good hand washing practices essential. Wash your hands or use an alcohol-based hand sanitizer frequently throughout the trip.

There are some special cases, Dr. Wheeler says. Babies born prematurely or babies with heart and lung problems or respiratory symptoms should have an evaluation and clearance from their pediatrician before flying.Always Be Prepared

One secret to a successful flight? Make like a boy scout and be prepared. "I wasn't too concerned about the flight," Caccavale Reynolds says. "I was worried about forgetting something."

Here's a look at the basics you'll need for air travel:

• Diapers, diapers and more diapers! (Dr. Sears recommends one diaper per each hour of travel, plus a few extras just in case.)
• Baby wipes.
• A changing mat.
• Disinfectant wipes. (These are great for cleaning off surfaces, including diaper changing stations, Dr. Sears says.)
• A change of clothes for Baby.
• Thermometer.
• Infant ibuprofen and acetaminophen (if your baby will be over 2 months old at the time of your trip) and medicine droppers.
• Ear-numbing drops (available by prescription from your pediatrician). "A few drops can quickly soothe a painful ear, whether the pain is from an ear infection or altitude pressure," Dr. Sears says.
• Nasal saline spray. "The biggest downside of airplane air is that it is very dry," Dr. Wheeler says. "It makes you feel miserable." A saline nasal spray used periodically during the flight will keep your little one's nasal passages moist.
• Plenty of pacifiers. Your baby will need to "pop" his ears by swallowing during takeoff and landing. If he doesn't want to be fed, a pacifier will help. "Even if you are anti-pacifier, this is the time to give in," says Kathryn Kaycoff-Manos, a mom of twins from Encino, Calif.
• If you are bringing along formula or expressed breast milk, be sure to bring it in a cooled, insulated container, Caccavale Reynolds says, as there may not be a fridge on board you can use.
• A few small, new toys. Try toys with many textures and black and white graphic patterns for this stage.
• One or two light blankets or wraps. These can double as burp cloths, provide warmth or even serve as a cover up for nursing if you're feeling self conscious.
• Anything else you think your baby will need.

Finally, expect delays. Travel is more stressful these days, especially for parents, Dr. Wheeler says. Make sure to get to the airport in plenty of time.

Airline seating can be tight. "If you can, upgrade," says Caccavale Reynolds, who used frequent flyer miles to upgrade to business class. The extra room really came in handy, especially when nursing her daughter.A bulkhead seat anywhere on the plane will provide extra room. Be sure to avoid being seated in emergency exit rows.

"If you have a baby who falls asleep to white noise, try to get a seat over the wing," says Smith, whose son fell so soundly asleep as the plane took off that she didn't get to feed him until landing. The vibrations and noise are a great way to lull your baby into dreamland – and if that seems implausible, think of all the newborns who love to nap while a parent vacuums!

No matter how you feed your little one, be prepared to do plenty of it on the plane, especially during takeoff and descent, when swallowing will help her depressurize her ears. "While liquids are no longer allowed on board an aircraft, passengers traveling with babies can bring formula, breast milk and electrolyte replacement drinks," Dr. Sears says.

"I intended to breastfeed on the plane, but took bottles of expressed breast milk for the airport, or in case she wouldn't nurse," says Susan McGowan, a mother from Columbus, Ohio. "I printed out the Transportation Security Administration (TSA) rules that covered breast milk and freezer bags, in case anyone tried to hassle me. No one mentioned it."

Both Smith and McGowan found that a window seat was preferable to an aisle seat for nursing. "If you're concerned about [privacy] while breastfeeding, get a window seat," Smith says. "It's much easier to be discreet when you're not in the aisle with people jostling past every 10 seconds." And if you are nursing or pumping milk for your baby, remember to stay well-hydrated yourself.A Seat of Baby's Own

Please consider bringing your baby's child safety seat along for the flight. While the Federal Aviation Administration (FAA) currently allows children under age 2 to be held on an adult's lap, most experts – including the American Academy of Pediatrics – now recommend parents book a separate seat for baby and bring their child seat. "It costs more, but in the event of turbulence or an emergency landing, it's simply safer," says Dr. Robert Wheeler, medical director for On Call International, a global travel and medical assistance provider.

For babies 3 months and under, it's a great idea to use an infant carrier-type seat due to its versatility, says Jeanna Rimmer, a representative of Britax, a market leader in quality child safety seats. Most infant carriers can be used with a stroller to function as a travel system, making it simple for you to transport your baby through the airport. Most airlines will then allow you to gate check your stroller.

"When traveling on an airplane, parents should only use child safety seats that specifically state 'approved for flight,'" Rimmer says. "Also, consider checking with your individual airline for rules and regulations before traveling with infants or children." (According to the FAA, child safety seats should be no wider than 16 inches across for the best fit on an aircraft.) Make sure to use the instructions for lap belt installation, and remember that babies under 1 year of age and 20 pounds should always be rear-facing.