All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
First of all, the adulterer must be punished according to the rules of Sharia and the baby isn`t attributed to him. Rather, it is attributed to the mother. This adulterer has committed a grave sin and incurred the wrath of Allah. We advise him to make sincere repentance to Allah and pray that Allah forgives him. And Allah The Almighty Knows Best.