There were will be wanton sex among teenagers in seedy basements and backseats of cars this weekend if social conservatives are correct about the ramifications of the FDA's decision last week to allow Plan B, the emergency contraception, to be sold to 17-year-olds without a prescription.

Emergency contraception is a term used to describe what is usually simply a higher dose of the same hormones used in oral birth control pills, taken up to five days after intercourse to prevent pregnancy.

Opponents of emergency contraception have fought its availability for nearly a decade, claiming that it promotes promiscuity and that it is tantamount to an abortion. They are certainly wrong about the former and likely wrong about the latter.

But, alas, with a new president in the White House, they no longer have a friendly force in power to ignore basic science.

Fringe minority rule

You might recall the saga: In 1999 the FDA approved for prescription use what is still the only brand of emergency contraception available in the United States, Plan B. In 2003 an FDA panel of outside advisors overwhelmingly recommended that Plan B be made available for nonprescription use without restrictions. The vote was 23 to 4.

Unfortunately one of the four naysayers was family man David Hager, a Bush-appointed conservative Christian (now twice divorced) who, as he stated on numerous occasions, wanted to do God's work. So he persuaded the Bush-appointed acting FDA Commissioner Lester Crawford to ignore the advice of the panel, for only the second time in FDA history, and postpone a decision indefinitely.

Meanwhile, the magazine The Nation, which had interviewed Hager's first wife in May 2005 about his years of spousal rape and sodomy, obtained a videotape of sermon that Hager gave in his home state of Kentucky in which he explained what had happened at the FDA: "I argued from a scientific perspective, and God took that information, and he used it through this minority report to influence the decision," he said. "Once again, what Satan meant for evil, God turned into good."

In August 2005, Susan Wood, FDA assistant commissioner for women's health, resigned in protest over the FDA's failure to approve Plan B for over-the-counter sales. By August 2006 the new Bush-appointed FDA acting commissioner, Andrew C. von Eschenbach, after a year on the job, reluctantly allowed sales of Plan B without a prescription, but only from behind a counter and only for customers aged 18 or older.

Last month a U.S. District Court ruled that the FDA's decisions — or, the decisions of but one or two at the FDA, because the staff was furious about what had transpired — were politically motivated, if you can believe it. This prompted the FDA to amend the rules.

Let the sex begin

The availability of Plan B has some worried that more young people will become sexually active, perhaps in the same way that stomach pumps in emergency rooms have encouraged the widespread pastime of consuming poisons.

Their logic seems clear enough: "I'll have sex tonight now that Plan B is available without a prescription," says the high school girl, "and I'll forego the use of a 50-cent condom and just pay the $50 tomorrow for some pills."

Unfortunately no leeway is given to the more obvious scenarios:

  • "I got really drunk and someone had sex with me. Now what?"
  • "I had sex but my naive boyfriend and I didn't use a condom because he said he'd pull out."
  • "Oh no, the condom broke."

Abortion or contraception?

The question of whether Plan B induces abortions likely never will be resolved, but the evidence is now weak. Plan B and other forms of emergency contraception work primarily by preventing an egg from leaving the ovary or preventing sperm from reaching an ovulated egg.

If the egg is fertilized, emergency contraception might be able to prevent the egg from attaching to the uterus, which is the medical and governmental definition of pregnancy. Some religious groups consider this an abortion. But studies indicate that emergency contraception does not dislodge an implanted embryo, which is why the pills are not as effective four days after intercourse and largely ineffective after five days.

Remember, the real abortion pill that terminates an established pregnancy is called RU-486. Some religion groups like to toss that in with emergency contraception just for confusion's sake.

Ironically, keeping Plan B out of the hands of 16-year-olds — and limiting access to all women in general — will ultimately lead to more abortions. But logic hasn't played well in the discussion these last 10 years.

Christopher Wanjek is the author of the books "Bad Medicine" and "Food At Work." His column, Bad Medicine, appears each Tuesday on LiveScience.