I did one. I'm a physician, and my WH is a stay at home dad. When I realized id have to pay alimony if we divorced, despite the fact he cheated, I told I'm to sign a post nupt or leave.
I consulted an attorney. I highly recommend that. He told me "It would sting if you divorce, but it is worse when you are married for 20 years or more".
PM me if you want more details.