For teens, having had sex for the first time at an earlier age has been linked to a dramatically higher risk of contracting a sexually transmitted infection (STI). This is according to a study conducted in South Korea.
The researchers used data from a Korean national survey of youth risk behaviors that is conducted annually by the Korean Centers for Disease Control and Prevention. More than 525,000 teens in seventh to 12th grades completed the survey between 2007 and 2013. Only 22,400 of those who responded (about 4%, said they had had sexual intercourse, and only their responses were considered in this study.
The teens reported when they had had first intercourse. The age at first intercourse, they said, ranged from before elementary school to twelfth grade. About 7% of the 4% who had sex said they had experienced an STI, which includes diseases such as gonorrhea, syphilis, chlamydia, HIV infection or other infection.
The younger the age at first intercourse, the greater was the was the risk of having had an STI, which was especially true for boys. For example, compared to teens who had first intercourse in twelfth grade, those whose first experience was in seventh grade were three times more likely to have had an STI.
In Korea, parents often avoid talking with their children about sex. Sex education has not changed there in over 10 years, even as children have increased access to sexual materials online, Seo Yoon Lee of the Institute of Health Services Research at Yonsei University in Seoul told Reuters Health.
The study was published in the Journal of Sexual Medicine.
In another study from 2012, South Korean teens had their first sexual experiences around age 15, on average. But this study found that several hundred teens claimed that they first had sex before elementary school or in first or second grade. For kids reporting first intercourse in second grade, risk of STI was nine times higher for boys and seven times higher for girls compared to first intercourse in twelfth grade.
This very young age for first intercourse is surprising and may mean that the survey is not accurate. "We, too, think those ages are extremely young," Lee said. "Or it is possible to think of the abuse too, but again, it is very hard to tell why."