It's a known problem called puerperal psychosis.

[link to www.rcpsych.ac.uk]

This is a leaflet created by the Royal College Of Psychiatrists OP, you might want to glance through it. I just have and could not at a glance see mention of one of the severest symptoms that often leads to what you are claiming but it is a leaflet for patients.

That is that in this post partum stage women with a puerpal psychosis can often view the child as an alien existence, alien as in strange not greys, and condider them a threat and a danger so unfortunately can wish to do the baby harm. It is a very serious condition and unfortunately some of it's effects can be found in other post natal problems and conditions.

There are a lot of factors environment as the female is growing up including abuse, the neurological damage as a consequence being affected by the resultant hormonal and chemical changes and imbalances with the obvious disruption to the synapses as just an example.

All you numptys do is shoot your load, they have a hell of a lot more invested both emotionally and physically and sometimes it bites 'en on the ass so to speak. Consider this and try a little understanding. You never know it may even get you laid at last