Nearly 30 per cent of U.S. teenagers have sent a nude photo of themselves via text or email, according to a study suggesting that the practice of sending explicit digital missives is more prevalent than once thought.

As well,“sexting” -- sending sexually charged texts or email messages -- could shed light on whether a teen is engaged in risky sexual behaviour.

Researchers at the University of Texas Medical Branch found adolescents who sexted were more likely to have had multiple sex partners, and have used alcohol or drugs before doing the deed.

While 28 per cent of respondents reported sending a nude photo of themselves, a sizable 31 per cent admitted to having asked someone for an explicit photo.

Even with the prevalence of sexting, enabled by the progression of smartphone technology, more than half of the teens surveyed reported feeling bothered by sexting requests.

Among the respondents, who ranged in age from 14 to 19 years old, girls reported being egged on for nude photos more often than boys. Conversely, boys were significantly more likely than girls to admit to having asked someone for a sext.

The findings, which are based on a survey of nearly 1,000 students in southeast Texas, hint that many teens don’t consider the potential consequences of sending sexually charged messages.

“You may think you’re sending it to one individual. That one individual, in turn, may be forwarding it on,” Dr. Marla Shapiro, a medical consultant for CTV’s Canada AM, said Tuesday.

For girls in particular, the stakes may be higher. There appears to be a connection between teenage girls who sext and risky sexual behaviour, according to the study, which was published in the Archives of Pediatrics and Adolescent Medicine.

But regardless of gender, Shapiro noted that sexting can have long-term effects on a teen’s reputation and overall sense of self-worth.

Instead of just taking away a teen’s phone, she said parents should open up a dialogue with their teens about sex and cellphone or computer usage.

When conversing with teens, Shapiro recommended putting sexting in perspective.

“You need to think twice about: Is this behaviour that you would be comfortable with in person, in front of a large group of people? Because that’s really what you might be doing here,” she said.