This is dead wrong. Animals, including hominids, have always been spartan about their children. The maternal instinct is there, but there's also the "this doesn't feel right so I'm eating all of you" instinct and many others. If you google you will find a vast spread of animals consuming or abandoning their offspring. When a mother is stressed or starving, miscarriage is far more likely--in other words, biology itself can favor the mother's well-being over the offspring. If conscious abortion were possible among animals, I'm certain some would engage. Anyway, I read this about two weeks before your post and I think it covers it: https://medium.com/the-authentic-eclectic/theres-no-logical-argument-against-abortion-656d76cbb3fc