Studies have been done showing that of all babies born IN WEDLOCK in the USA, about 5% are not the biological child of the husband.
This is quite common, and the law and customs need to address it! Saying the baby looked more like the milkman than like his putative "father," is no joke!
I have seen studies where that figure is quickly approaching 10% in urban America, and over 20% in low income areas.
There needs to be a law passed mandating DNA testing of parents before the signing of a birth certificate, something that feminists are fighting against like mad. They have no problem with men being duped into supporting other men's children.