Other than though necessity (for example following bereavement) I guess it was when feminists started telling women that motherhood was beneath them !

I don't understand how women can think motherhood is beneath them when motherhood is objectively one of the most important jobs that exists and is a task where the woman is basically constructing the future. I suppose the opposite is pure egoism and I suppose this might be why so many feminist types seem so self-centered.
I don't understand self-centeredness. Being self-centered is against one's own self-interest. It's in a person's own interest to not be selfish. To be an entirely atomized individual is not in one's self-interest.