With the brouhaha over Bristol Palin’s pregnancy, here’s a plus no one’s considered: should this young woman go to college as a married mom, she’ll be spared four years of the campus hook-up culture.

That’s no small thing. I was a campus physician for years, and know firsthand how students suffer from the toxic Sex in the City lifestyle on our campuses. College health and counseling services are packed with casualties of the anything-goes sexual mentality; many are girls who practiced “safer sex.” They did as they were told and used “protection,” but still paid a hefty price: genital warts and blisters, pre-cancerous conditions, worries about slipped condoms and HIV—to say nothing of chaotic, empty relationships and broken hearts.

These young women had been misled, and had a false sense of security. They were led to believe—not only by Hollywood, but by the nation’s leading sex ed organizations and popular health education sites like Columbia University’s GoAskAlice.com—that they are just like men, that sex is easily separated from emotions and procreation, and that with “protection,” casual liaisons can be a natural, positive part of growing up.

That philosophy is a result of social activists of the last century: Alfred Kinsey, Hugh Hefner, Gloria Steinem—figures that Bristol’s generation study in history class. Even the HIV-era notion of “safer sex” was developed years before they were born. While you’d hardly know it from the advice these kids get from sex educators or Columbia’s Alice, the world has changed. In this century, we’re fighting a horde of bugs, and the bugs are winning.

Canonized by the sex ed industry and considered transparent truths, “safer sex” guidelines are out of date. In 2008, it’s not enough to communicate with “partners,” get tested for STI’s, and use condoms. These days, young people—especially girls—who wish to avoid sexually transmitted infections need a different plan.

If we are serious about protecting our daughters, we must spell out a clear, no-nonsense message: the ideal is to delay sexual activity, and eventually commit to someone who also waited. The closer she can get to that, the better. Then provide her with some critical facts she’s unlikely to hear elsewhere:

As millions of American parents send their daughters off to college this week, many have a silent prayer on their lips. For good reason: sexual behavior is a serious matter, and a single encounter can have life-long consequences, especially for a woman.

Listen up, Planned Parenthood, SIECUS, and Columbia University: That’s not sexist—it’s biology. And ignorance or denial of this fact only increases a girl’s vulnerability.

We need to remind girls that the characters on Grey’s Anatomy are not real. In real life, Meredith would have herpes or warts. In real life, she’d be paying a price for her choices. Young women must know that now more than ever, it’s wise to follow the lesson of hard science: be very, very careful about who you allow close to you.