I travelled from London to Perth via Hong Kong when I was 34 weeks pregnant. Truthfully I was fine even tho it was a very long flight. I wore the recommended pressure stockings and we had a few hours stop in Hong Kong before our next flight which helped ease it a bit. I did find that by the time I got off the plane in Perth I had really really swelled up - quite funny actually the difference between before flight and after flight. Was slightly a bit uncomfortable on flight itself but all the hosties were so nice and accomodating, they really went out of their way to look after me.