Teens who admit to sexting are seven times more likely to engage in risky sex, according to a study published in the journal Pediatrics.

Teens who sext are seven times more likely to engage in risky sex than teens who have not exchanged explicit photographs, according to a survey of Los Angeles teens published in the journal Pediatrics.

Sexting, which involves sending or receiving sexually explicit text messages or photos by cellphone, is part of a "cluster of risky sexual behaviors among adolescents, rather than a substitute for 'real world' sex," according to the study by researchers from University of Southern California in Los Angeles published online Monday.

It included data from more than 1,800 Los Angeles high school students ages 12 to 18. Three-fourths of them had cellphones.

Of those who had a cellphone or access to one, 15 percent said they'd sexted and 54 percent said they knew someone who had. Those who said they had sexted were more likely to report being sexually active and having had unprotected sex during their most recent sexual encounter, compared to those who did not sext.

"In this study, certain populations of adolescents were more likely to report sexting, including black/African-American and lesbian/gay/bisexual/transgender participants," a release announcing the findings said.

The researchers hope that physicians will talk about sexting as an introduction to a conversation about sexual activity, sexually transmitted infections and prevention of unwanted pregnancy. They also advocate adding sexting and related behaviors to school-based health classes.

It's not the first study to say teens who sext engage in other high-risk sexual activity. Reuters noted that, "A study of Houston, Texas, high schoolers out earlier this summer found one in four teens had sent a naked photo of themselves through text message or email, and those kids were also much more likely to be having risky sex."

That study found that "girls in particular who'd sent naked photos were more likely to engage in risky sex, to have had multiple recent sex partners or to use alcohol and drugs before sex," Reuters reported.

“The same teens who are engaging in digital-sex risk-taking through sexting are also the same teens who are engaging in sex risk with their bodies in terms of being sexually active and not using condoms,” lead study author Eric Rice, an assistant professor at the University of Southern California’s School of Social Work in Los Angeles, told CNN.

“A lot of young people think that their friends are sexting, and if you think that your friends are sexting, you’re much more likely to sext yourself,” he added. The study said 17 time more likely.

He suggested that sexting might be a more comfortable topic for parents to introduce than a discussion on sex itself and it could lead to a broader conversation.

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