Q. I'm 33 weeks pregnant. Is it safe to travel by airplane on a cross-country trip?
A. Unless your obstetrician advises otherwise, it's generally safe to fly long distance at this stage of pregnancy. Keep in mind that some airlines prohibit air travel in the last four weeks of pregnancy and, if you look obviously near term, may require a note from your health-care provider stating your estimated due date (restrictions vary from carrier to carrier, contact the individual airlines for details). Even if your airline does not require a note, it's still a good idea to bring one along.
Since the larger airplanes used for coast-to-coast travel have pressurized cabins to compensate for the lower levels of oxygen at high altitudes, cross-country travel is theoretically safer than short, small-aircraft commuter flights. These usually fly at low altitudes and are therefore not pressurized.
Spending a short time in an unpressurized cabin is unlikely to harm your baby (a baby's oxygen level in the womb is already lower than mother's), but it can -- very rarely -- reduce the oxygen level in your own blood, causing you to feel lightheaded. Oxygen levels can fluctuate even in a pressurized cabin, so you may feel lightheaded in either setting. If you experience lightheadedness or are disoriented, ask the flight attendants for some oxygen.
