The researchers looked at teen pregnancy and birth data from 48 U.S. states to evaluate the effectiveness of those states' approaches to sex education, as prescribed by local laws and policies.

"Our analysis adds to the overwhelming evidence indicating that abstinence-only education does not reduce teen pregnancy rates," said Kathrin Stanger-Hall, assistant professor of plant biology and biological sciences in the Franklin College of Arts and Sciences.

Hall is first author on the resulting paper, which has been published online in the journal PLoS ONE.

The study is the first large-scale evidence that the type of sex education provided in public schools has a significant effect on teen pregnancy rates, Hall said.

"This clearly shows that prescribed abstinence-only education in public schools does not lead to abstinent behavior," said David Hall, second author and assistant professor of genetics in the Franklin College. "It may even contribute to the high teen pregnancy rates in the U.S. compared to other industrialized countries."

Along with teen pregnancy rates and sex education methods, Hall and Stanger-Hall looked at the influence of socioeconomic status, education level, access to Medicaid waivers and ethnicity of each state's teen population.

Even when accounting for these factors, which could potentially impact teen pregnancy rates, the significant relationship between sex education methods and teen pregnancy remained: the more strongly abstinence education is emphasized in state laws and policies, the higher the average teenage pregnancy and birth rates.

"Because correlation does not imply causation, our analysis cannot demonstrate that emphasizing abstinence causes increased teen pregnancy. However, if abstinence education reduced teen pregnancy as proponents claim, the correlation would be in the opposite direction," said Stanger-Hall.

The paper indicates that states with the lowest teen pregnancy rates were those that prescribed comprehensive sex and/or HIV education, covering abstinence alongside proper contraception and condom use. States whose laws stressed the teaching of abstinence until marriage were significantly less successful in preventing teen pregnancies.

These results come at an important time for legislators. A new evidence-based Teen Pregnancy Prevention Initiative was signed into federal law in December 2009 and awarded $114 million for implementation. However, federal abstinence-only funding was renewed for 2010 and beyond by including $250 million of mandatory abstinence-only funding as part of an amendment to the Senate Finance Committee's health-reform legislation.

With two types of federal funding programs available, legislators of individual states now have the opportunity to decide which type of sex education -- and which funding option -- to choose for their state and possibly reconsider their state's sex education policies for public schools, while pursuing the ultimate goal of reducing teen pregnancy rates.

Stanger-Hall and Hall conducted this large-scale analysis to provide scientific evidence to inform this decision.

"Advocates for continued abstinence-only education need to ask themselves: If teens don't learn about human reproduction, including safe sexual health practices to prevent unintended pregnancies and sexually transmitted diseases, as well as how to plan their reproductive adult life in school, then when should they learn it and from whom?" said Stanger-Hall.

Note: If no author is given, the source is cited instead.

• Teen Health
• Sexual Health

• Educational Psychology
• Child Psychology

• Educational Policy
• Public Health

• Sex education
• Adolescence
• Nutrition and pregnancy
• Special education
• Gynecologic hemorrhage
• Maternal bond