Anything is possible in a/b/o.
Mangaka makes up the rule for their own work. In this world mpreg is possible for any gender.
Yeah i guess you ar right ¯_(ツ)_/¯
Wow what a rule! We need that "love is an illusion" too.
From what I know, betas have always been able to get pregnant, because they make up the majority of the population (or else the human race might go extinct). It's just that their fertility rate are lower than that of the omegas. It was alphas that sometime are set to be unable to bear children, which is really popular in Chinese ABO setting where AO relationships dominate. Most Japanese ABO mangas have setting like this one tho
But seriously! A/B/O originated in Supernatural (the TV show) RPF fandom and has spread to original novels and manga. You can literally do anything you want with the trope. That's what makes it so fun. The website fanlore.org has info about the origin if you're ever curious. https://fanlore.org/wiki/Alpha/Beta/Omega
I know that betas can children too what i meant "beta males". If a beta male and a beta women or beta male and another woman can have childrens but since the male ones has no body parts like omega males. Omega males are like...how do i say...more girly? (Their bodies) so what i meant was when a beta male and an alpha male together how can they have children?
Wait a minute... Can betas have children too? Since when? And why i dont know? But good manga love it