New York does not recognize the validity of surrogacy contracts, and the parties to such a contract can be penalized if money changes hands. The courts have developed an intent test to determine who is the true “mother” of the child, the birth mother or the genetic mother. If the birth mother is not the genetic mother, but is the woman who arranged to be impregnated with another woman’s genetic child and intends to raise the child as her own, then she would be considered the mother of the child and have the legal rights of the mother. If the genetic mother arranged to have the birth mother carry her baby and intends to raise the child as her own, then she can seek to be granted the legal rights of the mother.
Fortunately, the State does not expect hospitals to make these sorts of determinations. The birth mother would be recorded as the mother and sign the birth certificate in either case. If the genetic mother wants to seek recognition of her rights under this intent test, then she would petition to have a new birth certificate issued, either through an adoption proceeding consented to by the birth mother or a court proceeding if the birth mother does not consent.