TALLAHASSEE, Fla. -

The Florida Supreme Court is hearing oral argument in a child custody dispute between two lesbians that could have broader implications.

Tuesday's case could force state lawmakers to reconsider a law on the rights of sperm and egg donors.

One of the women, the biological mother, donated an egg that was fertilized and implanted in the other. That woman gave birth in 2004.

The Brevard County couple separated two years later.

At issue is the definition of motherhood. A trial court granted custody to the woman who gave birth, saying the biological mother has no parental rights. He cited the state law that says donors relinquish parental rights.

An appellate court ruled both should have parental rights because the biological mother wasn't a donor as contemplated by the law.