WEDNESDAY, July 22, 2015 (HealthDay News) -- Less than half of U.S. teenagers aged 15 to 19 are having sex, a rate dramatically lower than it was a quarter-century ago, a new federal government report shows.
Only 44 percent of girls and 47 percent of boys between the ages of 15 and 19 had sexual intercourse at least once from 2011 to 2013, the researchers found.
That's down from 51 percent of girls and 60 percent of boys in 1988, said study author Gladys Martinez. She is a demographer/statistician with the National Center for Health Statistics (NCHS), part of the U.S. Centers for Disease Control and Prevention.
The drop in teen sexual activity is most likely due to the AIDS epidemic and the cultural shift that resulted from increased awareness of sexually transmitted diseases, said Dr. Jill Rabin, co-chief of the division of ambulatory care & women's health programs-PCAP Services at North Shore-LIJ Health System in New Hyde Park, N.Y.
"I think the '80s were a little bit different time than now," Rabin said. "We didn't really understand HIV at that time, and we didn't understand the impact of having unprotected sex. People still had a mentality left over from the '60s and '70s regarding free love and that sort of thing."
The study authors found other evidence that teenagers have become more responsible when it comes to sex:
- About four out of five teens now use a contraceptive method when they first have sex.
- Teenagers are more likely to use contraception when they first have sex if they wait until they're older, and they are more likely to wait. "That makes sense," Rabin said. "As you get older, you get more mature, more educated and, hopefully, more responsible."
- Teenage girls are less likely to become mothers during their teen years if they use contraception when they first have sex. "That's probably because they are in a trajectory where they are more likely to use it again," Martinez said.
The survey involved more than 2,000 boys and girls aged 15 to 19 drawn from a national sample, as well as an additional 1,770 men and women aged 20 to 24 to capture those teens who had sex on the cusp of young adulthood, Martinez said.
The report is published in the July issue of the CDC's NCHS Data Brief.
The likelihood of sexual experience increases with age, the researchers found. Only 18 percent of boys and 13 percent of girls had sex by 15, but that increased to about 44 percent of boys and girls at age 17. By age 19, two-thirds of both boys and girls had had sex, the findings showed.
About 79 percent of girls and 84 percent of boys used contraception when they first had sex, but they were much more likely to use contraception if they began having sex later in their teens.
For example, 99 percent of boys who had their first sex at 18 or 19 used contraception, as opposed to 82 percent for those 17 and under. The same held true for girls -- 93 percent used contraception at age 18 or 19, compared with 77 percent for those aged 17 and under.
The condom remains the most common contraceptive method used by teenagers, with 97 percent of girls reporting using a condom at least once.
About 60 percent of girls said they had used withdrawal as a contraceptive method, and 54 percent had taken birth control pills.
Even though withdrawal is a very flawed method of contraception, Martinez said it's not surprising so many kids turn to it.
"We find similar data for even older people," she said. "Withdrawal is always a top method people report."
The survey also found an uptick in the number of girls who had ever used emergency contraception, from 8 percent in 2002 to 22 percent in 2011-2013.
Martinez said that's likely because emergency contraception has become more accessible and widely available across the nation.
Visit the U.S. Centers for Disease Control and Prevention for more about teens and sexual risk behaviors.