anyone have any links to sites, even archived, of birth stories? For some reason, the particular story that made me think of this was entitled,"Big Twins Born in the Great Outdoors".

Yeah, there's:

https://drive.google.com/drive/folders/0...01jbEdsZHM

And also:

https://drive.google.com/drive/folders/1...85zg8LBbVy

There used to be more, but many people have either deleted or set them to private. Tumblr is a pretty good place to go though, although it sucks a lot these days. Many stories get taken down nowadays. You can also try Deviantart, they have a lot of birth stories - search through the groups and you'll find hundreds of people that write birth fics. I know a lot about birth fics, I don't recall this specific story though... sorry.

birthficsandpics.tumblr .com

Believe it or not, some fanfiction sites with more explicit or erotic content have some good stories with this kind of stuff. Pretty niche for each fandom though. I think there are subreddits for this as well.