Without looking it up?
Yes, yes, misspelling of birthist, but what would a birthist be?
Birthist. Latin counterpart: natalist.
It’s an –ist, so it’s either a profession or a profession of ideology, and with a Germanic stem preceding it, it’s likelier to be an ideology.
I’d guess someone who advocates being born as something special. The closest we have to that in the real world is nativist: being born in the country should give you priority over immigrants to the country.
There’s also birther, someone who advocates the conspiracy theory that Obama was not born in the US; that could easily have ended up as birthist instead, but it hasn’t.