Welcome to FlyerTalk, first post for OP. I do think this question is similar to people on honeymoon asking regarding chances of being upgraded.
What I mean is that both being pregnant and getting married is a special situation for an individual person involved. However, from airlines prospective it is everyday occurrence and it is nothing special.
Being pregnant or getting married is a special situation. However, can guess how many people are getting married every single day and how many of them are flying for their honeymoon. Also, can guess how many pregnant people are out there and how many of them are flying every single day.
I do think from the perspective of airlines, having a pregnant passenger is not something special, happens every day, and it is pretty much impossible for airlines to upgrade all pregnant passenger coming onboard airplane.
I think OP is looking for a situation of getting upgrade without paying fare difference or using miles. Nothing against OP, but my thinking is that OP needs to have something more than just being pregnant if OP is looking for free upgrade from an airline.
OP may think if there is an empty business class seat during the flight then politely ask a flight attendant. But I heard that at American Airlines flight attendants can get fired by doing something like that if a company finds out about it.
The risk conditions you have listed regarding flying while pregnant may be true, but some pregnant people are in higher risk of such conditions than other pregnant people. Your doctor has cleared you for the trip. Then an airline will assume that you are at lower risk for conditions you have described regarding flying while pregnant.
Originally Posted by
Occasional Traveler
It is not unusual to upgrade someone with a broken leg or arm because of lack of maneuverability. This is not much different.
You may have heard or read somewhere that is the situation. But from my experience such is not the case. I had situations where I was asked to move from my aisle seat to middle seat to accommodate a passenger with broken leg or arm. One situation I was given voucher for changing seat. However, I have not came across a person with broken arm or leg received free upgrade because of that. A person with broken leg or arm may have paid for first/business class seat because of his/her condition.