As far as I know none. That would just be an ordinary pregnancy.
That would be fascinating if there is one where one of the girl is the alpha which carries the sperm.
I dont think so. I know there is a yaoi omegaverse where the MC has 2 moms but I cant remember which one.
I was reading this story on wattpad that's girl x girl and one of them is an alpha.
but since it's on wattpad so you can imagine how poorly written it is
In Kashikomarimashita Destiny the uke of the second couple has two moms, maybe that's the one you're talking about :)
Is there any yuri omegaverse?