Still, some research suggests that adolescents who take pledges to remain abstinent until marriage do work. On Tuesday, research released by the Journal of Adolescent Health suggested that those age 12 to 17 who make such pledges delay having sexual intercourse longer than other adolescents who are similar to them but who do not take such a pledge.
"Our data suggest that it is a good idea for teens who are inclined to delay sex to make a pledge, because they're more likely to delay sex if they do so," said lead study author Steven Martino, a behavioral scientist at RAND in Pittsburgh, in a press release issued Tuesday.
Still, sexual health experts maintain that comprehensive sex education is more effective than abstinence-only programs. And they point to Bristol Palin's situation as evidence.
"It is impossible to ignore such a public example of how abstinence education -- even strong parental values -- are not enough to help young people negotiate their own sexual feelings and desires," said Pepper Schwartz, professor of sociology at the University of Washington in Seattle.
"Hopefully, teens will get the message that having sex at a young age at all -- and certainly without protection -- is unwise," said Judy Kuriansky, a clinical psychologist at Columbia University Teachers College. "Hopefully it will make parents wake up to see that their kids are not listening to them ... and as a result they will fall into the same predicament as Bristol Palin, who likely didn't use protection because that would have been really against her mother's approval."
But Unruh says it should be parents -- not educators -- who should talk to children and teens about sex.
"The fact is that it is a private matter," she said. "We think 'family first,' and we think that parents are the primary sex educators of children. But children will make their own decisions."
"We don't know the whole story. ... In this case, nobody has heard her story."
Michelle Schlief contributed to this report.