Unprotected Sex in Teens

Girls More Likely Than Boys to Have Unprotected First Sexual Encounter

Medically Reviewed by Laura J. Martin, MD on November 07, 2010
From the WebMD Archives

Nov. 8, 2010 -- Teenage girls are 30% more likely than boys to have unprotected sex the first time they have sexual intercourse regardless of any previous sex education instruction, new research indicates.

Researcher Nicole Weller, a doctoral student at Arizona State University, examined data on 5,012 young people between ages 11 and 19 from the National Survey of Family Growth, a comprehensive ongoing study that started in 1973.

Her study was presented at the American Public Health Association 138th Annual Meeting in Denver.

She tells WebMD that teens between 15 and 19 are delaying their first sexual encounters to about  age 17.5, compared to age 15 a decade ago, but that young people in that age group have the highest percentage of sexually transmitted diseases.

Many Teens Having Unprotected Sex

Weller tells WebMD that 13% of the total sample said they used no protection the first time they had heterosexual sex, specifically intercourse.

She says teens raised without religion were 14% more likely than those reared with it to say their first sexual intercourse was unprotected.

Weller tells WebMD that her findings were surprising because boys generally have been thought to be more prone to risky behaviors, such as engaging in unprotected sex. But she says that’s apparently no longer the case, if it ever was.

The survey was done in such a way as to encourage young people to tell the truth, using computers instead of face-to-face interviews. Still, she tells WebMD, the findings suggest that “females are starting to engage in risky behaviors” and may not worry about using protection if “they love and trust their partner,” which outweighs what they may have learned in sex education classes or from parental lectures.

“When people are talking about sex, oftentimes they aren’t necessarily truthful,” she tells WebMD. “Boys are going to lie in one direction and girls are going to lie in the other direction.”

Other key findings of the study:

  • Less than 1% of those questioned had their first sexual experience at age 11.
  • 2.5% reported their first sexual intercourse at age 12 and 6.7% at 13.
  • About 13% reported having sexual intercourse for the first time at age 14, about 16% at age 15, some 20% at 16, 12% at 18, and 5% at 19.
  • African-American teens were 41% more likely than whites to have unprotected sex in their first encounters.

“Sex education exposure itself wasn’t a significant predictor of somebody having unprotected sex the first time,” she tells WebMD.

“More than 80 percent of students get some type of sex education in the school,” she says. Additionally, young people frequently get  sexual education from parents, peers, and medical professionals.

This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.

Show Sources


News release, Arizona State University.

American Public Health Association 138th annual meeting, Denver, Nov. 6-Nov. 10, 2010.

Nicole Weller, Arizona State University.

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