Actually I don't think infanticide is as universally evil as its cracked up to be.

Don't get me wrong judging by my personal ethics infaticide is wrong and once we will have artificial uterus's and genetic therapy abortion will also be wrong on about the same order of magnitude.

But going by general human behavior rather than specific ethical systems both infanticide and abortion where generally accepted far more than today. Not only that the specific notion that something magical happens when a organism passes through the birth canal making it worthy of moral consideration seems to be a very modern and Eurocentric thing.