Overall, companies refuse pregnant women beyond the 7th month … because of the threat of a sudden in-flight delivery (which could cause diversions)

But each company has its own rules (sometimes it is the 8th month)

The advice for pregnant women
Ask priority boarding
Request a side corridor to facilitate access to toilets
drink plenty of water (because the atmosphere of an airplane dehydrated.)
do not wear clothes that shake because the altitude is a little inflated members
try to walk for long trips to avoid the risk of phlebitis
no alcohol
if traveling by air pressurized, Do not for a flying at high altitude because your fetus could miss oxygen, especially if you are in the first trimester of pregnancy
Choose a flight early morning or late evening to avoid the heat. Compete well in advance to you to reach the airport, and you escape the stress of traffic, and the fatigue of an extended trip car
After the trip, remember to relax, to compensate for fatigue-related jet lag

Seat belt
pregnancy-states against does not wearing a seat belt off and landing
seat belts will be placed flush thighs and not on the abdomen.

But let us not affolons

So far, but could not prove that there is a link between miscarriages or birth defects (due to radiation) and flights, as indicated by a large study of the University Hospital of Zurich

So do not panic!