Researchers say about a third of high school students having sex didn't use a condom during their last encounter. Health Reporter Erin Billups sits down with a sociologist working with young teens on how to avoid risky sexual behavior and filed the folowing report.

Laurie Bauman, a sociologist and pediatrics professor at Albert Einstein Medical College, has spent years researching teen pregnancy and HIV in the Bronx. She says the conversation with adolescents about safe sex practices needs to start earlier. 

"When we interviewed teenagers after our programs were over to ask them what we could do better, almost always they said, 'I wish I could have had this when I was younger," says Bauman.

Supported by a federal grant, Bauman examined sex ed courses in which teens discuss with each other what they are learning. She found that such courses not only worked with older teens, but with 12 to 14 year olds, too.

"There is some knowledge that we have to transmit.  But we can do it in a fun way, we can do it with games, we can do it competitively, we can do it in a way that makes them excited to be part of it," says Bauman.

Bauman says her previous studies have shown that when it comes to relationships - where teens believe they're in love - they were more likely to have unprotected sex. 

So during the 12-week program with the younger kids they focused on romance, condom use and how to discuss sex with a partner. 

"The intervention significantly increased HIV knowledge. It increased their confidence in not having sex, so we talk about abstinence, and we encourage them to stay abstinent until they're ready, and it increased their intention to stay abstinent," says Bauman.

But Bauman says just putting teens in a one-time class isn't going to end risky sexual behavior.

"I don't think it's a vaccine model, where we can give them information and skills and then say, 'Go, you're protected," she adds.

Bauman says sex-ed classes each year of high school taught by trained professionals may produce even better results.

"Teenagers told us, 'I don't wanna talk to my English teacher about this, I don't wanna talk to my math teacher about this, I'm uncomfortable," says Bauman.

This fall, she'll work with Montefiore Hospital offering courses in 12 Bronx high schools. This, at a time when many public schools are not offering mandated sex ed.

And for parents, she says, encourage conversations around sex as soon as possible.