[DISCLAIMER: I Cut & Paste] (This is already happening in the Netherlands, where infanticide—while technically murder—is so widely accepted that Dutch doctors who euthanize babies published the “Groningen Protocol,” a bureaucratic infanticide checklist for use in deciding which babies can be ethically euthanized.
[AND] Peter Singer made that very point in Practical Ethics:
Regarding newborn infants as replaceable, as we now regard fetuses, would have considerable advantages over prenatal diagnosis followed by abortion. Prenatal diagnosis still cannot detect major disabilities. . . . At present, parents can choose to keep or destroy their disabled offspring only if the disability happens to be detected during pregnancy. There is no logical basis for restricting parents’ choice to these particular disabilities. If disabled newborn infants were not regarded as having a right to life until, say, a week or a month after birth it would allow parents, in consultation with their doctors, to choose on the basis of far greater knowledge of the infant’s condition than is possible before birth.
Infanticide also common in the American Empire.
I’ve read that infanticide was common in Europe until recently. It’s probably been common, period.