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How Many Teens Are Really Having Sex These Days?
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The percentage of teens in the U.S. who have had sex has ticked down since the 1980s, a new report finds.

The latest estimates — which are based on data gathered from 2011 to 2015 — are that 42 percent of girls and women ages 15 to 19 who have never been married have had sex, down from 51 percent in 1988, according to the report. For guys who have never been married, 44 percent have had sex, down from 60 percent in 1988.

These trends follow another pattern that researchers have observed in previous studies: Teen birth rates are also on the decline, according to the report published today (June 22) by researchers at the Centers for Disease Control and Prevention. [10 Facts Every Parent Should Know about Their Teen's Brain]

Indeed, the researchers found that the surveyed teens' views on pregnancy played a large role in their decisions about whether to have sex and their likelihood of using contraception.

In the report, the researchers analyzed data on more than 4,000 teens ages 15 to 19 who were interviewed for the National Survey of Family Growth (NSFG) from 2011 to 2015. The NSFG is a national survey of people ages 15 to 44 in the U.S. that involves in-person interviews conducted by the survey researchers.  

The majority of teens in the survey said that when they had sex for the first time, it was with someone with whom they were in a relationship: 74 percent of teenage girls and women said their first partner was a significant other, and 51 percent of teenage boys and men said the same.

A very small percentage of teens — 2 percent of teen girls and women and 7 percent of teen boys and men — said that their first partner was a person that they had "just met," the report found.

Among the teens who hadn't had sex yet, the most common reason was that it was against their religion or morals. Other common reasons included not having found the right person and not wanting to get pregnant or to get someone pregnant.

The new report also looked at contraception use among teens.

The researchers found that 80 percent of teens reported using contraception when they had sex for the first time. And among teenage girls and women who'd had sex more than once, a whopping 99 percent reported that they had ever used some form of contraception when they had sex.

Teens cited condoms as the most common form of contraception they used during sex, with 97 percent of girls and women and 95 percent of boys and men saying that they had ever used condoms. Also, 60 percent of teen girls and women reported having used the withdrawal method (the report did not give the percentage of boys and men who reported using this method), and 56 percent of teen girls and women reported ever using birth control pills, according to the report. [7 Surprising Facts About the Pill]

The researchers also found that a larger percentage of teen girls and women said they would be "very upset" if a pregnancy occurred compared with teen boys and men. Nearly two-thirds of teen girls and women said they would be very upset if they got pregnant, compared with 46 percent of teen boys and men who said that they would feel the same if they got a girl pregnant.

Indeed, teenage girls and women who said that they would be very upset about a pregnancy were also more likely to use contraception compared with those who said they would be pleased with a pregnancy, the researchers found.

And one in five teens who have never had sex cited not wanting a pregnancy as their primary reason for avoiding intercourse.

Originally published on Live Science.