Former US Republican vice presidential candidate Sarah Palin's daughter Bristol, who gave birth to a son when she was just 18, is urging teens to think twice before having sex.

Bristol Palin, who once said it was unrealistic to ask young people to abstain from sex, is using her fame as the daughter of the darling of conservatives to warn teens to "pause before you play."

In a new public service announcement, the 19-year-old acknowledges that being Palin has made her teenage pregnancy easier than most.

"What if I didn't come from a famous family?" she asks in the ad, appearing with her son Tripp. "What if I didn't have all of their support?

"Believe me, it wouldn't be pretty," she says as the room grows bare and she looks disheveled.

The television spot will begin airing in May to coincide with National Teen Pregnancy Prevention Month.

The Candie's Foundation, a division of clothing brand Candie's that raises public awareness of teen pregnancies, released the television and print campaign. Palin was named an ambassador for the group last year.

In a statement, Palin spoke of how much her life has changed since she had her child and the difficulties she has faced.

"I believe that people need to start talking about the consequences of teen pregnancy," she said.

"Being a single teen mom has affected every aspect of my life. I am providing for another person and doing everything for him. I am constantly juggling and it is extremely difficult. Teens need to understand the realities of being a teenage parent."

During her mother's campaign as running mate to Republican Senator John McCain in his failed White House bid, Bristol Palin was thrust onto the public stage with her child's teenage father, Levi Johnston. They have since broken up.

The teen birth rate in the United States fell two percent between 2007 and 2008, after rising the previous two years, according to data released Tuesday by the Centers for Disease Control and Prevention.

Nearly 750,000 US teens become pregnant each year, the Candie's Foundation noted.

"The numbers are staggering and it is a national epidemic," said Neil Cole, the foundation's founder.

"By drawing attention to the issue and starting a dialogue between teens and parents, we can reduce this number and prevent teens from becoming a statistic."