Teen sexuality is a greater danger than many people realise.

According to a Newsweek report on prostitution by middle class girls, a quarter of all teens have sexually transmitted disease. Some 200,000 babies are born to girls under age 18. The odds of depression and suicide are three-to-four times higher for the sexually active compared to those who remain chaste. What can parents do to curb teen sexuality?

The Newsweek reports a frightening development among teenage girls. There is a "marked increase in teen prostitution in cities across the nation."

While most teen prostitutes are runaways, illegal immigrants or in poor areas, a growing number now come from middle class homes. One expert reports "Compared to three years ago, we've seen a 70 percent increase in kids from middle to upper-middle class backgrounds, many of whom have not suffered from mental, sexual or physical abuse."

The story tells of "Stacey," 17, who lives with her affluent parents and hangs out at the Mall of America in Minneapolis. "Cute, blond and chatty, she flirted with boys and tried on Gap fashions."

Last summer, an older well-dressed guy asked if he could buy her some clothes, a $250 outfit which she went home with. He was a pimp. Though she gets good grades in school, and is home by midnight, she learned she could make a lot of money stripping for men in hotel rooms, and more yet in more intimate activities.

A detective who helped bust a major teen prostitution ring, says, "This could be your kid." America's sex drenched culture is luring teens into sex in more mundane ways. Although the percentage of teens who are sexually active has dropped slightly, the overall rate is still high.

In 1997, 48 percent of US high schoolers were having sex. Some problems with teen sexual activity are well-known. Every day, 8,000 teens become infected by a sexually transmitted disease (STD) and three million will contract an STD this year, according to a book by Dr. Meg Meeker, "Epidemic: How Teen Sex is Killing Our Kids."

One fourth of the sexually active are infected. Pregnancy: 240,000 babies were born to girls aged 18 or younger in 2000. Their odds of long-term poverty and welfare dependence are high.

However, there are less well-known consequences. The Heritage Foundation reported recently that "early sexual activity is a substantial factor in undermining the emotional well-being of American teenagers."

Compared to teens who remain chaste, "teenage boys and girls who are sexually active are significantly less likely to be happy and more likely to be depressed." A full quarter (25.3 percent) of teenage girls who are sexually active report that they "are depressed all, most or a lot of the time."

By contrast, only 7.7 percent of inactive teenage girls report similar depression. That's nearly a 4-1 ratio. Among boys, 8.3 percent of the sexually active are often depressed vs. only 3.4 percent of those remaining pure.

Dr. Meeker writes, "Teenage sexual activity routinely leads to emotional turmoil and psychological distress... (Sexual permissiveness leads) to empty relationships, to feelings of self-contempt and worthlessness. All, of course, precursors to depression."

More alarming, that depression can lead to suicide. Heritage reports, "A full 14.3 percent of girls who are sexually active have attempted suicide. By contrast, only 5.1 percent of sexually inactive girls" have done so.

Thus, girls having sex are nearly three times more likely to attempt suicide. The gap is almost ten-fold among boys. Only .7 of one percent of inactive males have attempted suicide, while six percent of the sexually active have tried to kill themselves. Therefore, parents, what are you doing to warn your children about these risks?

Perhaps the best thing I did as a father was to follow the advice of Dr. James Dobson. I heard about some tape recordings of his called "Preparing for Adolescence." He urges a father to take his son, or a mother, her daughter, off on a special weekend for their 12th birthday, with no other family member present, and listen to the tapes together.

My oldest was 15 at the time a bit late, but not too late. I took him (and other sons at age 12) to a resort for their first experience playing golf.

We had great meals and went fishing. On the drive over and back, we listened to Dr. Dobson warn of the dangers of adolescence, of the temptations each would face. Many exciting doors would open to them - alcohol, a more dangerous one, drugs. And, of course, sex. "You need to decide in advance what you are going to do," he said.

His words flowed so much better than mine would have. However, Dobson encouraged parents to turn off the tape recorder at times, and add our own thoughts. You could add the horrifying data in this column that was not known 20-plus years ago when we went. They will listen to you or your spouse, because you demonstrated your love for them.