The best way to establish the paternity of the father is by naming the father on the birth certificate. According to the U.S. Department of Health and Human Services regulations, unwed parents or those in broken relationships must be offered an opportunity to establish paternity through voluntary signing an acknowledgment of paternity.
This can happen at the hospital or at a later time. In order to reduce the number of mothers on welfare in most states, they ensure that someone else has an obligation of paying support to the child. The personnel at the hospital do their best to get the father of the child to sign the acknowledgment.