WBRZ - Baton Rouge

A new national survey found that a growing number of teens say they use the rhythm method for birth control, and more teens also think it's OK for an unmarried female to have a baby.

Experts say those findings may help explain why there hasn't been a drop in teen births in recent years.

The Centers for Disease Control and Prevention on Wednesday released results from a sex survey of about 2,800 U.S. teens.

Teens' use of birth control changed little since a similar survey in 2002.

But there were exceptions - 17 percent of teens say they had used the rhythm method, up from 11 percent.

Also, the percentage of teen boys supporting unmarried motherhood rose dramatically.