Sperm donors don’t have the rights and responsibilities of fatherhood without a contract, a state appeals court has ruled.

In a complicated case in Washington state, the court said a man who fathers a child through a sexual relationship can be made to pay support, but has no responsibility if the same child is born in a test tube, the Seattle Times reported.

Michael Kepl of Pierce County, Washington, a married man, made a sperm donation to his long-term girlfriend, Teresa Brock, without his wife’s knowledge.

In 1998, Brock gave birth to a boy through in-vitro fertilization, and Kepl began paying up to $650 a month in unofficial child support, the Times said. He also took out a life insurance policy in the baby’s name and signed a paternity statement.

But for the court, the key issue was Kepl did not sign a contract saying he accepted legal responsibility

Washington’s law shield’s sperm donors from the legal duty of fatherhood unless couples sign a contract that specifically makes the donor part of the child’s life.

Brock had a second child with Kepl’s sperm in 2001, when their affair began to fall apart. Kepl insists he did not approve of the second pregnancy, but Brock contends it was his idea, the Seattle paper reported.

In 2002, Kepl stopped paying the child support, which led to a case brought before Pierce County Superior Court that granted Brock nearly $900 a month in child support, plus her attorneys’ fees.

The trial court favored Brock because it was a consensual affair.

But in its four-page ruling Thursday, the appeals court reversed the award, citing the state law.

Kepl, who says the affair was a mistake, claims he gave the benefits to Brock to keep her from talking to his wife.

“I would try to do anything I could to prevent her from finding out,” Kepl said, according to the Times. “The girlfriend knew it.”

Brock, with two mouths to feed along with her own, said the appeals court decision was financially devasting.

“This is a huge ruling, and not just for me,” she said. “There’s a lot of children out there where the father could walk away now.”

Lisa Stone, executive director of the Northwest Women’s Law Center, told the Times the case was important because of its potential effect on adoptive couples, particularly homosexual couples who rely on sperm donors.

“It’s just a weird case,” she said.

Stone noted the case protects people who want to have a child this way, along with the sperm donor.

“If you provide sperm, you’re not the father unless there’s a separate piece of paper that says this person will be the father and donor,” he said.

Kepl is now getting a divorce because of his wife’s anger over the affair, but he said he has not told the whole story to his teenage daughter.

“It’s been hugely traumatic,” he told the Times.

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