THURSDAY, Jan. 4, 2018 (HealthDay News) -- Fewer U.S. teens are sexually active these days, as many wait until later in high school to try sex for the first time, a new report reveals.
The proportion of high school students who've ever had sex decreased to 41 percent in 2015, continuing a downward trend from 47 percent in 2005 and 53 percent in 1995, according to data from the U.S. Centers for Disease Control and Prevention.
"The significance of these findings are important for today's youth," said Dr. Victor Fornari, director of child and adolescent psychiatry at Zucker Hillside Hospital, in Glen Oaks, N.Y. "This is very positive and promising."
The decrease is mainly driven by a decline in the number of 9th and 10th graders having sex, according to the report by Kathleen Ethier and colleagues at the CDC.
Sexually active 9th graders decreased from 34 percent to 24 percent between 2005 and 2015, while 10th graders having sex declined from 43 percent to 36 percent during the same time period.
By comparison, significant declines in sexual activity were not found among 11th and 12th graders, the researchers added.
Matthew Oransky is director of the psychology training program at the Mount Sinai Adolescent Health Center in New York City. He said, "What seems really promising about this is that the older you get, the better ability you have to make decisions and communicate and plan. The older you are when you initiate sex, the better able you will be to make healthy and responsible decisions."
The percentage of black and Hispanic teens experimenting with sex also went down, contributing to the overall decline in sexually active kids.
About 48 percent of black teens and 42 percent of Hispanic teens said they were sexually active in 2015, down from nearly 68 percent and 51 percent, respectively, in 2005.
On the other hand, sexual activity among white teens did not change significantly, the investigators found.
The decrease in sexual activity involved both boys and girls. Among 9th graders, about 27 percent of boys and 21 percent of girls said they had become sexually active in 2015, down from 39 percent and 29 percent, respectively, in 2005.
Health experts suggested that sex education is the most likely explanation for the trend.
"Much of this decrease can be tied to increased sex education, which includes sexually transmitted disease and contraception information," said Dr. Jennifer Wu. She is an obstetrician/gynecologist with Lenox Hill Hospital in New York City.
"Young people have learned that sexually transmitted infections are serious and are to be prevented," he said.
And, Fornari added, "Young women recognize that unwanted infants during adolescence is not desirable. From my perspective, education about sexually transmitted infections and the challenges of having a baby when a teenager have had an impact on adolescent behavior."
Wu is concerned the trend will not continue if educators aren't allowed to keep spreading the word about the consequences of teen sex.
"Ongoing educational efforts should continue," Wu said. "If funding stops or if there is a decline in sex education, we may then see a resurgence in teenage sexual activity and its accompanying consequences."
Oransky added that a cultural shift also might be at play, where adults are more comfortable having frank discussions with teenagers about sex.
"It's a big focus at our center, recognizing that -- whether or not we like it -- adolescents are making these decisions," Oransky said. "We have to arm them with the knowledge to make the decision that's most comfortable for them and best for their future."
The findings were published in the Jan. 5 issue of the CDC's Morbidity and Mortality Weekly Report.
For more on teenage sexual risk behaviors, visit the U.S. Centers for Disease Control and Prevention.