Television's influence on young viewers is a perennial hot topic. Now a Rand Corp. study gives parents one more reason to worry: too much TV may be associated with teen pregnancy. On the basis of phone surveys with 718 teens ages 12 to 17, researchers found that girls and boys exposed to high levels of sexual content on TV were twice as likely to be involved in a pregnancy by age 20 as were kids who watched less. This follows research that revealed a link between exposure to sexy TV and earlier initiation of intercourse. The investigators point out that not only do TV characters obsess about sex but they also don't think much about contraception — a reckless message for impressionable kids.