That's the conclusion of a new study by Canadian researchers who analyzed more than two dozen earlier trials of sex education efforts that targeted teens. They found that, overall, none made a dent in the odds that girls or boys would put off having sex or would use birth control when they did. None reduced the rate of teen births.
A separate analysis of four abstinence programs and one school-based sex education program showed they had the unintended effect of actually increasing the rate of pregnancies among the sex partners of boys. President Bush has called for "abstinence-only" sex education.
The findings, which other experts challenged, appear in the June 15 issue of the British Medical Journal.
Alba DiCenso, a professor of nursing at McMaster University in Hamilton, Ontario, and the lead author of the study, said it's too soon to declare sex education irrelevant.
Most of the trials her group reviewed pitted novel interventions against conventional programs. So the failure to find a difference might merely mean that the newer programs work just as well as the old ones, she added.
Still, DiCenso said, because teen pregnancy rates remain high in the United States, Canada and other countries where the studies were conducted, "we just haven't got it right yet."
The teen pregnancy rate in the United States has been dropping steadily in recent years. It fell 5 percent alone between 2000 and 2001, marking the 10th straight year of decline and a record low. The pregnancy rate for girls age 15 to 19 was 45.9 per 1,000 in 2001, off from 48.5 per 1,000 the previous year. The teen birth rate has plunged 26 percent since 1991.
The reasons for the steep drop are murky -- doubly so if sex education programs can't take credit. The booming economy of the 1990s might be one factor, DiCenso said. Others have said better contraception and less sexual activity among teens is behind the trend.
Experts have emphasized the need for comprehensive approaches to reducing teen pregnancies -- programs that focus on self-image, family and community. And DiCenso's group did find one trial of such an initiative that had a marked reduction in births among the girls who participated.
However, they said, girls in the comparison group appeared to have problems that made it likelier they'd become pregnant, potentially skewing the results.
Some experts disagreed with the conclusions of the Canadian study. Douglas Kirby, of ETR Associates in Santa Cruz, Calif., a nonprofit health education group, said lumping together so many studies diluted the effect of interventions that do work -- and those do exist.
Kirby, several of whose own studies were cited in the Canadian research, said he has found 10 components of sex education that can reduce teen pregnancy and influence adolescent sex habits. He said programs work when they use these approaches -- which include a focus on sex, not relationships or gender roles, a clear message to avoid unprotected intercourse, and a stress on abstinence as the best way to avoid sexually transmitted diseases and pregnancy.
Others may fail because they don't employ these methods, he added. Or it may be that they're not tried for long enough or in the right group of teens, he said.
Convincing teens to put off having sex and increasing the frequency with which they use contraception is "very difficult business, and many programs don't work," said Bill Albert, spokesman for the National Campaign to Prevent Teen Pregnancy, a Washington, D.C.-based nonprofit.
But Albert said his group has found that some sex ed initiatives can succeed -- though why isn't always clear.
Sometimes, efforts that make a difference don't target sexual behavior at all. A study the group conducted last year, for example, found that several community service programs that had teens cleaning parks, visiting nursing homes, and performing other tasks helped reduce sexual activity among the volunteers.
Again, Albert said, the reason for the effect wasn't clear. It might have been something as simple as reducing the time teens could have sex by filling their days with community work. Or it could have been the presence of committed, caring adults.
Yet Albert said these kinds of programs can only be one part of a larger strategy to drive down teen pregnancy.
"While they can be effective and are important, it's unrealistic and unfair to believe that these sorts of programs alone can make substantial progress in reducing teen pregnancy," he said.
What To Do