2nd trimester: I took a flight of 15 hours followed with 4 hours of local bus transport on my 16th week. Then do the same on my 18th week to return back. Everything was fine; but I must admit that I kept looking for toilet on the route. I did get a medical letter from my ganae that mine was of low risk pregnancy; also I spent more money to book a more comfortable seat on the plane. 3rd trimester: I took a flight of 5 hours followed with 3 hours bus transport alone on my 27th week. I book business class to make myself more comfortable. Advice: get medical confirmation from you gynae. Research local medical resources in case of emergency. Spend money to get yourself a seat nearer to toilet.
Not trying to scare you but I have 2 friends who suffered miscarriages after long flights (one was 5hr flight and another was 8hr+ flight) Both didn't have any abnormal feeling after the flight but the babies were not having heartbeat during their next scans. Both of them had their scans within days after the flight travel.
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