The second trimester (between 12 and 25 weeks) is generally the safest time to travel by plane.
During the first trimester (up to 12 weeks) you may be suffering from morning sickness and the risk of suffering a miscarriage also increases during this period. Having said that, there is no evidence to support any link between flying and increased risk of miscarriage.
During the third trimester (after 25 weeks) there is a risk high blood pressure as well as the chance of premature birth caused by stress or illness. You should talk to your doctor if you are thinking of travelling at this time.
You should check with your airline and insurance company that they will allow you to travel when pregnant. Generally, you will be able to fly while you are up to 28 weeks pregnant for long haul flights, and up to 36 weeks for short haul, but each airline varies with their policies. Airlines will sometimes request a letter from your GP stating your expected delivery date if you are 24 weeks pregnant. Women who have a high-risk pregnancy or a known health condition that might cause complications may not be allowed to fly in the last month of pregnancy. It is important to take into account the date of your return journey, as this may affect travel plans.
To ensure your flight is as comfortable as possible, drink lots of bottled water (with no ice as the air humidity is very low), sit in an aisle seat, wear loose clothing and comfortable shoes, adjust your seatbelt beneath your pelvis, keep your muscles moving by having short walks every now and again, and wear compression stockings to prevent developing blood clots. Symptoms of blood clots include swelling, pain, tenderness and redness particularly at the back of the leg below the knee.
May 2011 | 
How Can I Avoid Food Poisoning and Diarrhoea When Travelling?
