Teenagers who take virginity pledges are no less sexually active than other teens, according to a new study.

But the results, published in the journal Pediatrics, suggest that virginity pledgers are less likely to protect themselves against pregnancy or disease when they do have sex.

Researchers say the findings suggest that virginity pledges may not significantly affect teenagers' sexual behavior. Instead, they may decrease the likelihood of teenagers taking precautions, such as using a condom or using birth control, when they do have sex.

Researchers say the federal government spends about $200 million annually on abstinence promotion programs, which include virginity pledges. Two previous studies have suggested that virginity pledges can delay sex, but researchers say those studies did not account for pre-existing differences between pledgers and non-pledgers.