Air travel during pregnancy is not a great cause for concern if both mother and child are healthy. Nevertheless it is always best to consult with your gynecologist before undertaking the journey and especially if you are suffering from anemia, blood clotting disorders, placental insufficiency and sickle cell disease among others.
Most doctors advise that flight travel during pregnancy is best between 14-28 weeks, mid pregnancy when the likelihood of premature delivery or a miscarriage is at its lowest. If you have crossed 36 weeks then your health care provider is likely to dissuade you from traveling as chances of complications are higher. Besides most airlines have a policy against allowing women who have crossed that period from flying for fear of an on board delivery. If you are insistent about flying, then carefully read the travel guidelines as it may vary for each carrier. It would be prudent to request for an aisle seat which has more room and if possible in the front of the plane so that the ride is the smoothest and you and your child do not bear the brunt of possible turbulence. While buckling up might be a trifle difficult do not neglect to do so and you can buckle up by fastening the lap belt underneath your abdomen and across your thighs.
Short walks up and down the aisle every half an hour will help to ease out and prevent any cramps, but if you must remain seated, then try to flex your ankles, rotate them and extend them as often as you can. This will help improve the blood circulation in your body as well. Drink plenty of water even though you may have to visit the bathroom often as you can be dehydrated from the low humidity within the cabin. One of the things prospective mothers are worried about pregnancy air travel is the issue of enough oxygen available for both mother and child considering decreased air pressure will reduce the oxygen levels in your blood. You needn't worry about this as the body usually adjusts to this and besides you will not be flying continuously. Also try to avoid travelling to countries which insist on immunization as it might pose a risk for both you and the child. To avoid developing blood clots while travelling, you may want to wear support stockings and if you are prone to nausea, anti nausea medications before the flight will be helpful, but only after consultation with your doctor.