Having Children.....?

Ive seen many times where when people get married and have kids that the wives sometimes resent their husbands afterwards. Almost as if they give all of their love to their children and the husband becomes almost like an oddman out or third wheel or nousence. Even in normal marriages where the guy is a hard working man and does not have vices. Dont think this is post pardon if ive seen it happen so often. Any inputs?