COLUMBUS, Ohio (AP) – The constitutional ban on same-sex marriage in Ohio should prevent a woman from seeing her former partner’s 8-year-old son, the boy’s mother argues in domestic relations court.

Denise Marie Fairchild’s lawsuit asks the court to cancel Therese Marie Leach’s visitation rights. The boy, conceived through artificial insemination, was born while the women were still a couple.

The same-sex-marriage ban, which voters approved on Nov. 2, denies legal status to all unmarried couples, gay or straight. It’s also been cited in a Cleveland court case asking a judge to declare the state’s domestic violence law unconstitutional.

Fairchild said she voted against the ballot issue.

“I realize I am using a piece of legislation that will deny me rights later in my life. But before I am a lesbian and a member of the gay community, I am his mother,” she said.

At Fairchild’s request, the Franklin County Domestic Relations Court gave Leach parenting rights in 2001, saying the women “shall be treated in the law as two equal parents of their minor child.”

They sought the agreement so Leach could make medical decisions for the boy in Fairchild’s absence, Fairchild said.

The agreement is not valid because it was written before a 2002 Ohio Supreme Court decision that gave the domestic relations court the power to determine custody, according to Fairchild’s lawsuit.

Keith Golden, Fairchild’s attorney, says Leach shouldn’t be considered a parent under Ohio law because she did not give birth to the boy, did not adopt the boy and cannot marry Fairchild because of the same-sex marriage ban.

“She doesn’t fit into one of those criteria,” Golden said.

The custody case in domestic relations court gave Leach parental rights that contradict state law, Golden said.

Leach’s court-appointed attorney, Thomas Schmidt, did not return a message seeking comment. Leach does not have a listed telephone number.

Fairchild, 41, said she and Leach, 46, dated for eight years before the boy was born and they broke up three months later.

Shannon Minter, legal director for the San Francisco-based National Center for Lesbian Rights, said a similar case is pending before the Utah Supreme Court. In that case, the birth mother argues Utah’s anti-same-sex marriage law supports her claim to deny her former partner visitation to the child they once raised together, Minter said.

“What it underscores is the need for the law to protect the children in these cases and not let homophobia create a loophole that parents can exploit to the detriment of their own children,” Minter said.

David Smith, vice president of policy for the Human Rights Campaign, a Washington, D.C.-based gay rights advocacy group, said he was not familiar with Fairchild’s case and couldn’t comment on it. But he said Ohio’s constitutional amendment banning same-sex marriage is “being used for ugly purposes,” such as the domestic violence case in Cleveland.

In that case of a man charged with slapping his live-in girlfriend, a Cuyahoga County Common Pleas judge said he wouldn’t decide whether the amendment banning same-sex marriage and civil unions makes the state’s 25-year-old domestic violence law unconstitutional. The judge denied the man’s request because the domestic violence charge was filed before the marriage amendment passed.

At least 11 similar requests have been made on behalf of people charged with domestic violence in the Cleveland area.