I don't think I believe this account is genuine.
I am wondering whether this is in fact a troll who has decided to get a bit of propaganda out there about how some women really want to do this. But it reads like a male fetish fantasy. 'she' wants to have her belly swell etc. The motivation isn't even the altruism, it's the pregnancy itself, and the baby will be disposed of to someone else once the ride is over?
All sorts of alarm bells are jingling here.
Not buying this one.