Wait wait,so their child boy or girl?

i assume it’s like if a woman is an alpha they have a wiener too… but omega verse doesn’t exist in their world so must get registered as a male

Thank you for your explanation ╥﹏╥

He said oh "Alpha" female when the baby was given to him... But since they're in a world that doesn't recognize ABO they had to choose boy or girl

What about the baby's genitals?
They can decide by looking at the child's genitals, right?

Yup. That's why Weiwei wanted to register it as a girl-alpha (female alphas have "penis-like" genitalia in ABO universe so they can get their partners pregnant). But since the doctors discovered the baby can produce sperm one day but have a low chance of getting pregnant (again because Alpha Females are the ones who get their omegas pregnant), Lian Jue wanted to register her as a boy :( ... ABO is for both Yaoi (B/B) and Yuri (G/G)

I see,now I really understand, thank you for the explanation (⌒▽⌒)