ONE in three American girls falls pregnant before the age of 20, offering hope to Republican strategists that the electorate will shrug off the fact that 17-year-old Bristol Palin is expecting.

Educators, meanwhile, are hoping the national discussion about the pregnancy of the daughter of vice-presidential candidate Sarah Palin will renew the scrutiny of Federal Government-backed abstinence-until-marriage sex education programs.

"The US is so puritanical, and does not want to talk about sex," said Stephen Conley, executive director of the American Association of Sexuality Educators, Counsellors and Therapists. "Over the past eight to 10 years, we have had the abstinence movement take over sex education."