We all know that airline seats have been shrinking over the years. It's an annoyance for all travelers, but the reduced width and shortened legroom can be a nightmare for a pregnant woman. Factor in the queasiness of a first-trimester pregnancy, or the extra 25 pounds of the woman in her seventh or eighth month (that's me), and you have the makings of a nightmare.

There is no doubt that flying nowadays can be a hassle, yet it is often a  necessity, especially for the many women whose jobs require it.  Plus, with the recent "babymoon" trend drawing moms-to-be to luxury spa properties around the world, it is no longer just a necessity, but a means to end for vacationing future parents. Here are some current regulations, followed by my four top tips to help you survive the journey.

Airline Policies: According to Dr. Heidi Rosenberg, a New York obstetrician, it is wisest to avoid flying during the first eight weeks of pregnancy, when you're most likely to miscarry. Of course, she adds, during the last month of pregnancy there is always "the chance that you'll go into labor in midair or far away from home. Nonetheless," she adds, "I never recommend to my patients that they not fly, unless they are in a high-risk category." While it is smart to check with the airlines before you check in, a few phone calls revealed that most carriers are quite lenient when it comes to letting a third-trimester passenger board the plane. The most stringent rules are those outlined by Northwest Airlines and United, which state that any woman within 30 days of her due date must provide a doctor's statement that she is capable of flying, one which has been issued within 72 hours of departure. American and Continental require a medical certificate for a passenger within seven days of her due date, while Delta leaves the decision up to the individual. You may want to call the airline prior to departure to double-check on specifications. The only rule on which all the airlines seemed to agree was that a passenger who is visibly in labor will not be permitted to board the plane. (Do you blame them?) As always, it is best to consult your medical practitioner before you book your ticket.

#1 - Bulkhead Seats: With coach passengers packed together in steerage-like quarters, these seats at the front, which offer a few extra inches of legroom, seem positively luxurious. Unfortunately, they are often difficult to reserve in advance. Inquire if there are bulkhead seats available when you book your ticket. If the answer is no, you can continue to make regular calls to find out if the seats have opened up, and ask about the bulkhead when you get to the check-in counter. (It doesn't hurt to mention that you are pregnant, if it isn't obvious.) Often you will find that something is available. And don't balk if it is the middle seat: The ability to stretch out your legs (and exit to the restroom without making your fellow passengers go into contortions) more than compensate for the lack of view.

#2 - Bring Snacks: Many of the major airlines have cut out food service altogether, especially on short flights. When you book your ticket, ask what the meal service will be. If there is a meal served onboard, you might wish to order a vegetarian or low-cholesterol option, both of which are bound to be healthier. Still, it helps to bring your own snacks, because delays in the flight (or a seat in the middle or back of the plane) may mean that you are hours away from eating. Tote healthy munchies: a bag of cut-up vegetables with low fat dressing, cheese, a whole-grain muffin or crackers, fresh or dried fruit, a peanut butter sandwich on whole-wheat bread or even a bag of trail mix. And make sure that you bring a large bottle of water to keep yourself hydrated. The general rule is to drink about one liter of water for every two to three hours in flight.

#3 - Take a Walk: Sitting for long periods of time can hurt your circulation, leading to stiff legs at best, swelling legs and feet at worst. Try to take a walk around the plane every 30 to 45 minutes. Some light stretching exercises can help combat poor circulation: while in your seat try wiggling your toes, flexing your feet and stretching your arms above your head. And since you're sitting anyway, now is the perfect time to practice your kegel exercises.

#4 - Feeling Sick?: Whether you're struggling through your first trimester, or just battling a bad case of air sickness, one way to combat a queasy stomach is to try a remedy that many people use on the water -- sea sickness bands. These adjustable wrist bands, sold at many drugstores, have nodes at acupressure points to relieve nausea. Commercial names include ReliefBand, Bioband, and Sea Band. Make sure to drink plenty of fluids, as dehydration can cause nausea. Slow, deep breaths may also help relax you. Unfortunately, the only real cure for morning sickness is time.

Whenever you are traveling, pregnant or not, it helps to follow the above common-sense rules. With a little luck and planning, no matter what pregnancy stage you are in, the flight needn't be a miserable experience. If you already have children, as I do, you may find yourself looking forward to a few hours of enforced "down time." If you are carrying your first child, use the flight to catch up on reading, work on a crossword puzzle or simply close your eyes and relax -- something you will have a lot less time to do once your little bundle of joy arrives. 

Jennifer Lapidus contributed this to FTF while on maternity leave from Travel Agent magazine, caring for Justin Isaac (born March 8th ) and daughter Sophie (2).