The Role of the Man in the Process of Birth

An excellent point was made in class when the role of the man in the process of birth was brought up.  What exactly is our role?  While I submit that the woman is responsible for carrying the child to term and actually giving birth, the child's genetic material is still made up of 50% of his father's.  Does this mean that the men don't have a say? What if the mother wants the child to be born at home with a midwife but the father wants the child to be born in a hospital with a doctor?  I was watching "Mrs. Doubtfire" this evening and I noticed a particularly disturbing part.  Sally Field's character, Miranda, was given custody of the children following a divorce, and the judge admitted that custody hearings always tend to favor the mother.  Why is this? Stay at home dads are becoming more and more common.  Are we to believe that just because women give birth to a child that they are any more equipped to raise the child than a man is? I'll flip the situation and ask if we are expected to believe a man is more equipped to run a fortune 500 company just because they aren't able to have children?