In the situation of my brother and SIL, he was listed on the birth certificate.
I did a little research and this is what I found - hope it is helpful.
Name Changes for a Minor
Parents often wish to change their children's names when they make a new start in life. A name change for a child is simple, if the birth certificate was issued in Pennsylvania and both biological or adoptive parents consent to the change of name. Both of the biological parents must complete and sign the form on the back of their child's birth certificate. The form is then mailed to the Department of Vital Statistics. The Department of Vital Statistics will send the parents a new birth certificate containing the child's new name. Please note that Social Security will not change your child's name on his or her Social Security card unless you get a court order to change his or her name or you can show Social Security two acceptable forms of identification for the child, one in the child's previous name and one in the name on the new birth certificate. Some acceptable forms of identification include: a passport, school identification card, health insurance card and state issued identification card. It is very important that your child's name be the same on his or her birth certificate as on his or her Social Security card as it may otherwise be difficult in the future for your child to get a driver's license, passport or state issued identification card.
More information on changing a child's name on a Pennsylvania birth certificate may be found on the Internet at:
http://www.health.state.pa.us/vitalr...orrections.htm
A petition for a change of name for a child, where the other parent will not consent, should not be attempted without the advice of an attorney, because a petition must be filed in court. An attorney will help you find out if the Court is likely to grant a name change under the particular circumstances of your case. The following general rules apply to such petitions.
The Judicial Standard for changing the name of a child is "the best interest of the child." A parent or guardian who is seeking to change the name of a child must prove that the change is in the best interest of the child. The following matters are usually considered by the Court in determining whether to grant a petition to change a child's name:
The natural bond between parent and child. A change of name may affect the relationship between a parent and child. Most Courts find it in "best interest of the child" to maintain the link between parent and child. The Court will look at the parent's history of visitation with the child, whether child support payments have been maintained, and whether the parent has been consistently involved in the child's life. The Court must also consider the ties between the child and the parent's extended family.
The social impact or respect afforded a particular name in the community. A name change may be granted by the Court to protect a child from the bad reputation of a biological parent in the community. The link between the parent and child may cause embarrassment or problems for the child in school and the community. For example, a name change may be granted where a parent has committed a notorious crime in the community and the child suffers harassment because of bearing his or her parents' surname
The age and ability of the child to understand the significance of changing his or her name. A Court is reluctant to change the name of a child when it fears that the petitioning parent is motivated by self interest. Children who are involved in bitter divorces or custody battles are often influenced by parents. The Court may look to the child to figure out whether the child understands the impact of changing his or her name. A young child will most likely not be able to understand what it will mean to change his or her name. Of course, a teenager can probably express his or her desire and understanding of the impact of the name change to a greater degree. The Court will decide how much weight to give to the desires of the child.