It should be remembered that the birth father is going through his own struggles concerning the pregnancy. While those struggles may be different in many respects from the struggles the birth mother is going through, they are nonetheless real.
Some birth fathers take the pregnancy very seriously and really do want to parent the child. If the birth father can demonstrate that he is capable of being a reasonably good parent and seeks custody early, he will probably prevail. It is therefore important that he not be ignored. The last thing prospective adoptive parents want to have happen is to receive the child into their homes and bond with the child, only to have the birth father file for custody. For this reason, the birth father should be sought out and approached just as soon as possible. He also has a right to receive counseling about his decision. His consent is legally just as important as that of the birth mother. He should be treated with respect, even if his actions don't deserve it.
A birth father might deny paternity or demand a paternity test even when he knows he could have fathered the child, and even if he has no intention of parenting. He may be suspicious and not willing to sign a Consent Form which acknowledges paternity. Fortunately, he does not have to. The Consent can be written to state that he hs been named as the birth father and that while he does not acknowledge paternity, he nonetheless consents.
A birth father may take pride in the fact that he has a child even though he has no intention of parenting. He may oppose the adoption even though he is not capable of providing what the child needs nor has any intention to pay child support. The birth father may have a vague idea that his own mother will raise the child until he becomes able to, at some undefined future time. Or, he may insist that the birth mother raise the child just so that he can visit the child in the future if he wants to. These ideas may be reinforced by members of his family, or often, by a new girlfriend.