A new study suggests that nearly one in ten teens have same-sex partners - almost twice as many as previous research found.

According to a 2002 study of Massachusetts and Vermont teens, only 5 percent to 6 percent of teens had same-sex partners. In the new study, 9.3 percent of teens said they did.

“Clearly there’s a high rate of same-sex partners among teens, and we need to recognize any vulnerabilities that may be associated with these behaviors,” said Dr. Susan Blank, an assistant commissioner at the NYC Health Department. Blank, who was not involved with the study, was referring to a lower rate of condom use and unwanted sex among teens with same-sex partners seen in the study.

The new research, published in the journal Pediatrics, looked at more than 17,000 teens in New York City. It found that teens who had sex with only their own gender or with both genders were more likely to engage in risky sexual behaviors, putting themselves at greater risk for sexually transmitted diseases (STDs).

According to the U.S. Centers for Disease Control and Prevention, half of the 18 million new cases of STDs that occur each year happen among people aged 15 to 24.

Such risky behaviors included not using a condom during sex and having forced sex. More than half of boys who engaged in bisexual behavior didn’t use a condom, compared to a fifth of those who engaged exclusively in heterosexual behavior. The difference was not quite as large for girls who engaged in bisexual behavior and those who engaged exclusively in heterosexual behavior, but it was similar: About half of the former didn’t use a condom, compared to 30 percent of the latter.

About a third of those teens who engaged in bisexual behavior had forced sex at some point in their lives, much higher than the 6 percent of those boys who engaged exclusively in heterosexual behavior and the 16 percent of the similar group of girls.

Elizabeth Saewyc, a researcher at the University of British Columbia, told Reuters Health that these teens may engage in riskier behavior because sex education programs don’t always acknowledge gay, lesbian, and bisexual relationships.

“Some teens I’ve seen tell me that they completely check out of sex ed because they feel what they were learning didn’t apply to them,” said Saewyc, who was not involved in the new study.

She suggested that educators need to acknowledge gay, lesbian, and bisexual relationships more often in sex education curriculums so that teens are more likely to listen and will feel more comfortable discussing any issues.

Though the authors of the new study report that the rate of same-sex partners is higher than previous studies, Saewyc pointed that this rate is actually similar to what she has seen in her own work and other studies.

In the 2008 British Columbia Adolescent Health Survey, for teens who were sexually active, 8 percent of males and 10 percent of females reported having had a same-sex partner. In a study looking at the 2001 Minnesota Student Survey, 9.4 percent of teens reported having had partners of the same or both sexes.

Dr. Preeti Pathela, lead author of the new study, said the results may have been different this time around because some states do not measure same-sex encounters.

Still, Pathela said, it’s clear that some teens are more vulnerable to risky behavior and STDs than others. In discussing sexual relationships and potential risks, she said it is important that parents, educators, and researchers focus on behaviors and not just on sexual identity.

“How teens identify themselves doesn’t always correlate with actual behaviors,” said Pathela, a research scientist in the New York Department of Public Health and Mental Hygiene. “Behavior is a better measure of what’s actually happening because teens are changing rapidly.”

SOURCE:  Pediatrics, October 25, 2010.