April DeBoer (left) and her partner Jayne Rowse (second from right) are parents caring for four adopted children and a foster child who are petitioners in one of several same-sex marriage cases that will be heard by the U.S. Supreme Court next week. Reuters

Children raised in households with two moms or two dads turn out just as fine as kids raised by mixed-gender parents, according to the latest research on same-sex parenting, published this month. The study adds to the growing body of evidence that suggests gay and lesbian parents are just as fit to raise kids as heterosexual parents -- a reality researchers hope could influence future U.S. Supreme Court rulings on gay marriage.

“As same-sex marriage has been debated in courts across the country, there has been the lingering question about the effects of same-sex parenting on children,” said lead author Jimi Adams of the University of Colorado at Denver, in a statement. “I found overwhelming evidence that scientists agree that there is not a negative impact to children of same-sex couples.”

In light of the public’s shift toward greater acceptance of gay people -- more Americans today say they’re OK with same-sex marriage than ever before -- and the increased stability of same-sex households, whether such research could influence an upcoming Supreme Court ruling on gay marriage is unclear. The argument that children of same-sex couples are somehow disadvantaged has been largely absent from recent gay marriage debates, but researchers said it’s always possible that such a claim could come up.

An estimated 200,000 American children under the age of 18 are growing up in households with same-sex parents. An additional 1.2 million to 2 million children are being raised by gay or lesbian parents who are not part of a couple.

Adams and his team analyzed 19,000 studies conducted between 1977 and 2013 relating to same-sex parenting. They discovered a clear consensus: Children of same-sex couples are no more likely to suffer from psychological or behavioral problems compared to children raised by opposite-sex parents.

Some scholars have claimed that children of same-sex couples face added hardships -- an argument that has previously been used to challenge gay adoption or even marriage. A study published in February by the Catholic University of America claimed that children raised by same-sex parents had added emotional issues because at most only one of their parents could be biological. The authors argued that the reason children of opposite-sex parents didn’t have such emotional issues stemmed “almost entirely [from] the fact that married opposite-sex parents tend to raise their own joint biological offspring, while same-sex parents never do this.” However, the study was found to be flawed in its design, according to the Atlantic.

The latest research on same-sex parenting comes before a much-anticipated U.S. Supreme Court decision, expected by the end of this month, on whether gay marriage is legal in the U.S. The court will determine whether the Constitution supersedes state laws banning same-sex marriage. "I hope we’ll see acceptance of gay marriage of the courts and by the public at large," the University of Colorado's Adams told Reuters.