Though taking aspirin before takeoff may ward off clots for some people, pregnant women, among others, shouldn t do it. Check with your doctor. Once inside the plane, make sure you have as much room to move your legs as possible a good reason to store cabin baggage in the overhead compartment rather than under the seat in front of you where it can take up precious legroom. During the flight, drink lots of bottled water, avoid alcohol, straighten and move your legs and even consider wearing support stockings, which can improve blood flow in the veins. While some doctors suggest moving around the cabin every half-hour or so, many airlines recommend doing gentle exercise in your seat both for safety reasons and to avoid getting in the way of the cabin crew.
Some people can find a potential silver lining in any cloud.