MONDAY, Nov. 8 (HealthDay News) -- Teenage girls in the United States are more likely than boys to have unprotected sex during their first sexual experience, new research indicates.

The finding was a surprise to researcher Nicole Weller, an Arizona State University graduate student working on her doctoral degree in sociology.

"I'm looking at the interaction between sexual education and how it impacts young adolescent sexual behavior. This in particular was an interesting finding because males usually report that they are having more sex than females," Weller said in a university news release.

Her analysis of data from the National Survey of Family Growth also found that young people are waiting longer than in the past to have a first sexual encounter, but they are contracting sexually transmitted diseases (STDs) earlier than in the past.

"Fifteen- to 19-year-olds have the most sexually transmitted diseases. Even though they are waiting, they are having risky sex and not taking precautions," Weller said.

In addition, looking at disparities in sexual habits among different ethnic groups, the researcher found that black males and females are more likely than their peers to have unprotected sex.

According to Weller, it's important to provide sex education at a young age. "The younger one receives sexual education, the less likely you are to engage in risky sex," she said.

But the type of sexual education provided in U.S. schools is inconsistent -- from abstinence to STD awareness, and from birth control to pregnancy awareness. "It varies in school districts and from state to state," she added.

Weller is scheduled to present her preliminary findings Monday at the American Public Health Association's Social Justice Meeting and Expo, held in Denver.

More information

The American Academy of Family Physicians offers sex information for teens.