Teen Sex Rates Stop Falling, Data Show

The proportion of teenagers reporting having sexual intercourse rose steadily throughout the 1970s and 1980s, fueling an alarming rise in teen pregnancy. But that trend reversed around 1991 because of rising fears about sexually transmitted diseases, especially AIDS; changing social mores about sexual behavior; and other factors. At the same time, more teenagers reported using condoms and other forms of contraception. Together, the trends have pushed the teen pregnancy rate to historic lows, especially among African Americans.

"If there has been more progress made on another difficult major social issue, I don't know what it is," said Bill Albert of the National Campaign to Prevent Teen Pregnancy. "It's really a remarkable achievement."

But because the U.S. teen pregnancy rate remains far higher than those in other developed countries -- double the rate in England, for example -- the leveling off of sexual behavior is triggering alarms.

"Although we can celebrate the decline in teenage pregnancy, the United States still has a very high level of teenage births and pregnancy compared to other industrialized nations," said David Landry of the Guttmacher Institute in New York, an independent research institute that studies reproductive health issues. "There's still a long way to go."

Some fear that the leveling off in the rate of teenagers having intercourse could foreshadow a new upsurge in sexual activity, which could cause teen pregnancy and birth rates to climb again.

"My concern is that this plateau is the canary in the coal mine -- a harbinger of a reversal of these positive trends," said Michael D. Resnick, a teen health expert at the University of Minnesota.

The survey indicates that the increase in condom use may also be waning.

"It's not showing as strong of a stabilizing trend, but it's definitely slowing," Landry said.

The data on teen sexual activity come from the Youth Risk Behavior Survey, a nationally representative survey of about 13,000 students in grades nine through 12 conducted every two years by the federal Centers for Disease Control and Prevention.

The most recent survey data, from 2005, was released last year, but attention focused primarily on the overall change in sexual behavior from 1991 to 2005 -- both when the CDC initially reported the data in June and again earlier this month when the findings were highlighted in an annual federal report on the well-being of U.S. children. That comparison shows a significant drop, from 54 percent to nearly 47 percent, in the proportion of teenagers who said they had ever had sex. The fraction who said they had sex in the past three months fell from 37 percent to 34 percent.

Largely unnoticed was that the percentages for both measures did not change significantly between 2001 and 2005. In response to a request from The Washington Post, the CDC analyzed the data for that time period to validate statistically that the rates had leveled off, for all grades, for both boys and girls and across all racial groups.

"We found that, over that time period, there were no changes in the overall percent of high school students who had ever had sex," said Laura K. Kann, who heads the survey project at the CDC. "It has decreased over the whole time from 1991, but there's been no change since 2001. There was flatness for all the subgroups for all the variables."

Researchers are awaiting the data from this year's survey to see whether the trend has continued.

Columbia's Santelli conducted another analysis of the available data, comparing the results from two time periods -- from 1991 to 1997 and from 1999 to 2005. It supports the interpretation that the trend line flattened.

"It seems clear that the trend seems to be faltering in the most recent period of time," said Santelli, who plans to present his findings this fall at a meeting of the American Public Health Association.