It doesn't matter whether a couple is ready to have children or not, when a child is born, parental instinct will make the parents especially the mother to accept the child. I think that it's very rare for parents to hate their child, unless the child gives them a very good reason to hate him or her, especially through the child's character. It is wickedness for any parent to hate or abandon their child because children are innocent and it's the duty of the parents to love and care for them, if for any reason that they can not there physically for the child, they are obligated to send money for the upkeep of their child which is their responsibility.
As a parent, I can tell you that there's no such thing as a fixed 'child's character.' A child's character can change many times throughout their childhood. It is the parents' responsibility to help their child develop a good character, and this is achieved through love and care.