Sexting is growing among children in the United States, particularly as more of them use smartphones, according to new research.

Over the past decade, researchers studied more than 110,000 youths between the ages of 12 and 18, according to JAMA Pediatrics, a leading medical journal that publishes the latest clinical studies. The research, which was evenly split between boys and girls, looked at sexts that were sent, received, forwarded without consent and received without consent.

The prevalence of sexting — "sharing of sexually explicit images, videos, or messages through electronic means" — has increased in recent years as youths age and smartphone use increases, researchers said.

"The increase ... with age is commensurate with older youth having greater access to and/or owning smartphones compared with younger youth," researchers wrote.

The increased popularity of Snapchat — a smartphone app that deletes photos after 10 seconds — led to an expanded rate of sexting. The website Tech Junkie reports that originally it was teens who used the app for sexting, but now people of all ages use it. And, Tech Junkie warns, photos can be saved, even without the sender's knowledge.

"Perform a quick internet search for 'save Snapchat pics' or words to that effect, and you will see a few hundred websites purporting to show you how to keep snaps you are sent," stated an April 2017 blog. "Some will even show you how to do it without notifying the sender that you are saving the snap. That alone should send alarm bells ringing."

More studies needed

Researchers noted that the smaller studies contributing to the meta-analysis of the more than 110,000 children do not offer specific, consistent details about who is sexting when, only that it has increased over time and with the proliferation of smartphones. Delving further into the practice of sexting is needed for health care professionals to respond appropriately, they said.

"Media portrayals of sexting often implicate adolescent girls as the senders of naked photographs and adolescent boys as the requesters," researchers stated. "However, this popular belief and [data] were not supported by the present meta-analysis, which found no significant sex differences in the rate of sending or receiving sexts."

The earlier studies concluded that the percentage of tweens — or pre-adolescents — and teens who are sexting ranges "from 1.3 percent to 60 percent. The extent to which health care professionals, school personnel, policymakers, and parents should be concerned about this behavior is unknown." The meta-analysis narrowed that down to between 14.8 percent and 27.4 percent sexting among 12- to 18-year-olds.

Younger teens "may be particularly vulnerable to sextortion [nude images and/or videos used as a form of threat or blackmail]," researchers said, "and may be at risk for a host of risky behaviors and negative consequences."

"Further research focusing on nonconsensual sexting is necessary to appropriately target and inform intervention, education, and policy efforts," the team wrote.