The parents don't have to have been married before the child was conceived. However, they do have to be married before the child is born.
[header] How to establish paternity in ohio [title] Show the parents were married. [step] If both genetic parents were married before the child was born, the man is considered the presumed father of the child in ohio, and there's typically no need to establish paternity. [substeps] If the child's parents are married, all the father has to do is sign the child's birth certificate.