Adoption. Proof that you can pick your family.
Adoption has been around a hell of a long time. Since the she wolf (actually Latin slang for a prostitute, which explains a lot) adopted Romulus and Remus, excess children have been passed on to families that both wanted and could afford to raise them.
Adoption is in decline in recent years, as the whole idea that the right of a deadbeat, drug addled mother to oversee the welfare of whatever child she accidentally pops out now seems to over ride the right of the child to actually grow up in a safe, stable and secure environment.