My friend's baby was just born he is not married to the mother of the baby, he wants to get custody of the baby if the baby is his but there has not been a dna test done yet? Should he sign the birth certificate as the father without knowing if he is the father ? The mother is going to be released from the hospital today so he has to make a decision of whether or to sign today, not enough time to do dna test?

If he has doubts about being the father or not, he should get tested. If he signs the birth certificate, it will NOT matter if he is the father or not biologically, the law will hold HIM responsible.

And you don't have to sign the birth certificate imidately. It CAN be left blank as my daughters was when she was born.

The birth certificate can be amended later after paternity is legally established. If there is a doubt, hold out for the court ordered test.