If Bristol Palin is truly going to abstain from sex until she's married, as she promised in front of millions of viewers last week on the "Oprah Winfrey Show," she has her work cut out for her, experts say.
Teen moms such as Palin, 19, say it can be done, but statistics show that most teens who pledge abstinence abandon the vow within five years.
"Many of these kids who do pledge to remain abstinent do so in the classroom with their peers. It's a group event, so there's a lot of peer pressure," parenting contributor Ann Pleshette Murphy told "Good Morning America" today. "Not probably as much as being on Oprah.
"I think the point was, it is very hard," she said.
"I'm just wondering if that's a realistic goal," Winfrey said.
"It's a realistic goal for myself," Palin said.
Alisha Tew knows firsthand how difficult Palin's abstinence pledge can be to keep. She has stood by her own pledge for four years, ever since the birth of daughter Miley shortly after her senior year in high school.
"You never think that is going to be you who finds yourself in that situation and going to be a teen mom," Tew said. "For me, the hardest thing was how I was going to be a great mother, but still be a 19-year-old."
Four years after making her celibacy vow, Tew will walk down the aisle in May.
"When you really go through the experience and know how difficult it is, and the strength you need to have this baby in your life, than it makes it worth it to just wait," she said.
But not everyone can keep that kind of vow. A Columbia University study that followed 12,000 teens found that 88 percent of those who made an abstinence pledge had sex before marriage and had similar rates of sexually transmitted diseases to those who didn't take a pledge. They were also much less likely to use contraception.
"Abstinence works when it is used consistently and correctly," Monica Rodriguez, vice president for training and education for the Sexuality Information and Education Council of the United States, told "Good Morning America. "The problem is that abstinence isn't always used correctly, and when it fails, it has a really high failure rate."
Murphy said the reason the numbers are so high for abstinence-only kids not using contraception is because of the education they are getting.
"Abstinence-only programs, for the most part, don't teach you how to use protection," she said, suggesting that what's needed is a comprehensive education that encourages kids to wait while teaching them how to use contraception if they change their minds.
And that kind of education should start, she said, at home. Discussing contraception, she said, does not equal giving teens permission to have sex.
"Parents are the most important people in kids lives in terms of this," she said. "You have to share your values."
Palin became pregnant while still a high school student, and she has become a vocal advocate for teaching teenagers that they should practice abstinence rather than safe sex to avoid becoming pregnant.