Most pregnant women can continue to travel by air up to 36 weeks into their pregnancy, according to the Mayo Clinic. Every woman and pregnancy is different, however, and you should speak with your medical professional before booking your flight.
That said, even if you are cleared for your travel, there are some administrative complications that might arise and prevent you from flying. So, here are a few precautions and tips I've picked up from the many mothers I've interviewed for my family travel website, suitcases&strollers, about how to ensure your baby bump doesn't bump you off the plane.
1. Airlines have different corporate rules about when you can fly up to when pregnant. Check the official website of the airline you are booking to find out when is their cut-off date for when you can fly up to when pregnant.
2. Always get a medical certificate that clears you to travel. Even if you are well below the cut-off date for when you can fly while pregnant, having something in writing about how far along you are and how healthy the pregnancy is means there can be no arguments when you check in. Similarly, if you are carrying any medications with you, ask for your doctor to provide a letter stating why you need them.
3. Plan for travel sickness. Things in pregnancy can change quickly. The day you book your flight you might feel fantastic, but the day you fly might be the worst morning sickness you've ever experienced. Put contingencies in place (such as booking the aisle seat, bringing some sweets to suck on, only eating a light meal before boarding) just in case.
4. Visit the bathroom before you board. (Get used to talking about pee, you're about to spend the next several years doing it!) Even if you don't think you need to, go to the toilet before you get on the plane. Pregnant women need to pee a lot and your pelvic floor is already under a lot of pressure, so avoid being caught out during a long taxi and take off.
5. Pack snacks, but pack light. To avoid sudden bouts of nausea or hunger so common in pregnancy, have some small packs of dry biscuits with you. These are also useful for traveling to developing countries where you are concerned about food sanitation. But keep your suitcases and luggage to a minimum; although you might presume people will help a pregnant woman struggling with putting heavy bags in an overhead locker, trust me when I say that doesn't always happen.
6. Show off your bump. Flying in pregnancy means being in crowded tight spaces. Looking obviously pregnant sometimes helps people to be more careful of jostling or pushing you in their rush to get from A to B.
7. Carry a list of medical facilities at your destination for use in an emergency. Then, in the unlikely case that you need this information, you won't be scrambling around on Google in a panic stricken moment.
9. Relax! Enjoy the time on the flight where no one can call you, you're not responsible for anyone else and you can just chill out. You won't be doing that again for a very long time!