Is it safe to fly when pregnant? New travel guidelines offer advice
More than 60,000 women in Ireland are pregnant at any time - and there is always a worry about what is the safest time if they have to go on an aeroplane.
New guidelines now say the safest time to fly during pregnancy is before 37 weeks.
If a woman is carrying twins the best time is before 32 weeks, according to the Royal College of Obstetricians and Gynaecologists.
It says that flying is not harmful during a low-risk pregnancy, but there may be side-effects.
If more than 28 weeks pregnant, a woman should take her medical notes and a GP's letter.
Although everyone who flies is exposed to a slight increase in radiation, there is no evidence that flying causes miscarriage, early labour or a woman's waters to break.
The changes in air pressure and the decrease in humidity on an aircraft have not been shown to have a harmful effect on pregnancy either.
If the pregnancy is straightforward, flying is not harmful to the woman or her baby. Previously, the advice for women with multiple pregnancies was that the safest time to fly was before 34 weeks, but this has been changed to 32 weeks to tie in with International Air Transport Association (IATA) recommendations.
After 37 weeks, a woman may go into labour at any time.
Side-effects include swelling of the legs due to a build-up of fluid, nose and ear problems caused by changes in air.