The people who say “EMPTY EGG CARTON” to all women 30+ show how awful they are at knowing women’s bodies. Having kids too young also creates complications and can result in infertility.
I’ve also met young couples that still end up with special needs kids, so the assumption that any pregnancy 30+ automatically results in special needs also doesn’t understand probability. Women on average have a 1 in 10 chance of producing a kid with Down’s syndrome at age 49. Not many women would try to have kids at that age anyway or could have kids.
Overall, for how much some men claim to understand women’s bodies, they’re really bad at judging fertility and chances of special needs kids, among other things. Also, special needs can happen from the father’s side too, but I guess it’s easier to just blame women.