Brief answer....you can undertake long distance flight but need a nod from your doctor
Detailed answer.....
Hello,
Thanks for the query. 
I have read your query and understand your concern.
In most of the cases air flight is safe in first trimester of pregnancy according to association of XXXXXXX college of obstetricians and gynaecologists,however it should be discussed with your doctor regarding this as there may be certain medical issues with some individuals. In general problems are more related to discomfort rather than actual problem to mother or child,however still you must talk to your doctor.
So consult your doctor and take clearance from your doctor.
I hope it helps,however you are most welcome to revert to me for any further query.
Best of luck
Thanks

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