The mother infamous for that was eventually cleared and dingos did likely actually eat her baby. https://en.m.wikipedia.org/wiki/Dingo_ate_my_baby

And when it comes to humans:
"Almost all neonaticides are committed by mothers." - https://pmc.ncbi.nlm.nih.gov/articles/PMC2174580/

I mean, if men would have to carry the baby for nearly 10 months within their own body and after giving birth having to do all the care work like lots of women had and have to do, they would be baby killers more often as well.

Relevant Natural History Short

Well at least human males aren't known for going around and killing the babies of potential partners just to increase their chances at getting some, like those damn dirty prarie dogs! (sheesh, still a lot of mammals on the infanticide list though...)

Well at least human males aren't known for going around and killing the babies of potential partners just to increase their chances at getting some, like those damn dirty prarie dogs! (sheesh, still a lot of mammals on the infanticide list though...)

Oh boy do I have bad news for you:

Filicide overwhelmingly linked to male perpetrators who 'deeply believe their actions are justified', experts say

Filicide

It is not exactly the situation you mentioned, but I think it is at least highly related?

My head cannon says this behavior is approximated by step-parents being shitty to their step kids so that their own kids get preferential treatment. But I have no proof, just life experiences.