A Long Island mother whose fertilized egg was implanted into a surrogate lost her bid to be declared the mother on the child’s birth certificate — because a judge said the woman who gave birth is the baby’s legal parent.

Elaine Feigenbaum, 42, sued the state Health Department to be officially declared mom to the 1-year-old girl after St. Charles Hospital in Port Washington listed her friend, Carly Macomber, as the mother.

This despite the fact that the friends had an agreement declaring Feigenbaum to be the parent, and Macomber joining her pal in the legal request.

But Suffolk Supreme Court Justice Peter Cohalan said that state law doesn’t recognize such deals, and that the only way Feigenbaum could legally become the child’s mom is through adoption.

Feigenbaum’s husband, Marc, is listed as father on the birth certificate.

The couple decided to use surrogacy because of Elaine’s medical issues.

The Feigenbaums have cared for the child since taking her home from the hospital in June 2009.

They have decided to go through the adoption process, said their lawyer, Melissa Brissman.