They don't call it the boob tube for nothing.

A new study reports that teens who watch a lot of sex on TV are twice as likely to get pregnant or to get someone pregnant as their peers who watch the least number of steamy shows. The Rand Corp. analysis is the first to show a link between exposure to sexual content on television and a pregnancy before age 20. In Florida, nearly 48,000 teens get pregnant every year.

The study tracked more than 700 12-to-17-year-olds for three years and followed 23 shows, including dramas, comedies, reality shows and animated programs on broadcast and cable networks. Sitcoms had the highest sexual content. Sex and the City and Friends, two shows now in syndication, were included in the study.

Lead researcher Anita Chandra says the sexual content on television has doubled since the 2001 TV season when the study began. That's easy to believe when the 2008 season includes adolescent hits such as Gossip Girl, whose teen socialites bar hop regularly and have highly active sex lives, and Degrassi: Next Generation, which deals with rape, abortion and other so-called 'normal' teen sex issues. But, hey, parents can just turn off the TV, right? Yes, but Ms. Chandra says that nearly 80 percent of shows have sexual content - flirting, kissing, talking about and having sex - so there's only so much a V-chip, the feature that allows parents to block programming, can do. Plus, four out of five teens have cellphones, many of which have Internet and TV show access. In Florida, more than 600,000 Florida families are headed by a single parent not likely to have time to play television cop on a daily basis.

So, what can parents do?

Get the remote and grab a seat on the couch beside your teenager. In addition to limiting exposure to TV sexual content, parents should help their children balance what they see on TV with real-world consequences. Ms. Chandra says one reason TV sex may lead to teen pregnancy is that few shows depict the negative consequences of sex. 'Sitting down and watching shows together, talking about character portrayals gives parents the opportunity to discuss alternative outcomes, what might have been a negative consequence of those plot points,' Ms. Chandra says. 'They can be teaching moments.' Any concerned parent will be a much better teacher than Carrie Bradshaw.