Aetna approval good for how long?

I am going to my dr. tomorrow for my 3rd month documentation for a tummy tuck.  I have Aetna PPO and as luck would have it I just found out I am 5 months pregnant.  So no surgery now but should I still have the dr. submit my documentation for approval?  I would like to have the tuck after the baby is born.  I thought I read Aetna's approvals are good for a year?  Anybody know??  Thanks for your help.

for a tummy tuck not real sure but I inquired about moving my date and dr office advised i have a 6mth window with Aetna choice pos II and then aetna needs to be informed of the date you are going to have the procedure.

Yes thank you, it is 6 months my dr's office said we can submit all the paperwork to aetna after the baby comes.  Thank you for your help.