Being raised by a same-sex couple is no hindrance to healthy psychological development, researchers say as the first generation of children conceived by lesbians through donor insemination is coming of age.

In fact, lesbian mothers rated their 17-year-olds higher in social and academic skills, and lower in rule-breaking and aggression, than did mothers of teenagers who also had a father.

The study, which appears in the journal Pediatrics, is the first to follow children of lesbian couples all the way from conception to adolescence.

"There are so many places in the United States where same-sex couples are not allowed to adopt or foster children in need," said Dr. Nanette Gartrell of the University of California, San Francisco, who started the so-called US National Longitudinal Lesbian Family Study in 1986.

While opponents of same-sex parenting often mention cultural or religious values, some also contend that growing up with two moms or two dads can't be healthy for the child, said Gartrell.

But there isn't any solid evidence that homosexual parenting is any worse or better than its conventional counterpart, according to Gartrell, who is in a same-sex partnership.

"There is not a single study that has shown there are any problems in terms of psychological adjustment" of the child, she said. "The things we know that make for good parenting are love, resources and being very involved in your child's life."

The new findings are based on 77 families of both girls and boys. The researchers interviewed the lesbian mothers about their kids and then rated the teenagers on the Child Behavior Checklist, a standardized assessment that has been used for decades. Each teenager also filled out an internet-based psychological questionnaire.

When comparing the results to how mothers living in conventional families rated their teenagers, children of same-sex couples were more competent in school, had fewer social problems, broke fewer rules and were less aggressive.

Based on what the children reported themselves, they did just as well whether or not they knew the identity of their biological father.

However, those teenagers who — according to their mothers — experienced homophobia and bullying did turn out to be more anxious and have more depressive symptoms than their peers. It wasn't clear if the anxiety was a product of the bullying or if it was the other way around.

"What this data shows is that it's not the parenting that seems to be the issue," but rather the stigmatization, said Ian Rivers, a professor of human development at Brunel University in Uxbridge, England.

But he noted that homophobia was on the decline.

"We are starting to see a sea change," he said, adding that there was "an awareness in schools that homophobia is something that is inappropriate."

According to recent data, a good quarter million American children are living with same-sex parents. Rivers, who was not involved in the new study, said concerns about the children's well-being had not come true.

"These children have not faced many of the issues that critics of gay and lesbian parents say they should be facing," he told Reuters Health. "This is why this is such an important piece of work."

It is unclear why kids of same-sex couples would be in better psychological shape than those of heterosexual parents. While the researchers are still analyzing the internet questionnaires, Gartrell said one reason could be that lesbian mothers had planned their parenthood carefully and were prepared to help their children though any discrimination they might face.

"These were chosen children, they weren't accidents," Gartrell said.