US teen pregnancy rates have been falling
A study claims the declining teenage pregnancy rate in the US is down to better use of contraception rather than young people abstaining from sex.
The US government has promoted abstinence as its preferred way to cut the teenage pregnancy rate.
But the American Journal of Public Health study found it accounted for just 14% of the drop in conceptions among 15 to 19-year-olds since 1995.
UK experts said the finding showed an abstinence-only policy did not work.
The study was carried out by New York's Columbia University and the Guttmacher Institute, which specialises in sex education research.
It concluded that 86% of the decrease in conceptions was due to improved use of contraception.
Pregnancy rates for the 15 to 19-year-old age group fell in the US by 27% between 1991 and 2000.
The study found that abstinence was responsible for a slightly higher proportion of the drop in conceptions among the 15 to 17-year-old age group - but the figure was still only 23%.
Criticism of policy
The US government has come under fire for its policy on teenage pregnancy, which includes funding education programmes which eschew promotion of contraception in favour of abstinence.
Among the most high-profile critics has been film star Scarlett Johansson, who said if President George W Bush had his way US women would be completely uneducated about sex and have six children each.
In Britain the study was welcomed by the Independent Advisory Group on Teenage Pregnancy, which advises the government.
Gill Frances, chairwoman of the group, said: "This confirms that we are on the right track in this country, that providing young people with good information, advice and contraceptive services is the way to reduce teenage pregnancy.
"It is a myth that abstinence is a better approach and this US study confirms it."
Anne Weyman, chief executive of the Family Planning Association, said it was clear that the abstinence-only approach to sex and relationships did not work.
"Robust contraception services, comprehensive sex and relationship education and a mature attitude to young people's sexuality are the key components in bringing down teenage pregnancy.
"If we are expecting young people to make responsible decisions about their sexual health, they need information and support to do it. Simply telling them not to have sex isn't enough."
However, Eric Stanley, of the US group the Liberty Counsel, said abstinence did work.
He said: "You can't give somebody a condom and tell them it will be 100% effective - that would be giving them a false sense of security.
"We ought to be telling our teenagers to stay away from sex until they are married - it is the only 100% effective way to avoid a pregnancy."