During the George W. Bush Administration, one of the prime examples of politics trumping science was the FDA’s refusal to approve the emergency contraceptive Plan B (levonorgestrel) for over-the-counter sale without age restrictions. Now, during the Barack Obama Administration, history seems to be repeating itself.

Emergency contraceptives like Plan B can dramatically reduce the risk of an unintended pregnancy if taken within 72 hours after unprotected intercourse, but their efficacy wanes the longer a woman has to wait to take the drug. If a woman has to wait to see a doctor to get a prescription for an emergency contraceptive, that will add to the time between intercourse and dosage – or she may decide that she’d rather take her chances with pregnancy than scramble to see a doctor. For women with little access to healthcare providers – due to geography, cost, or other factors – the requirement to get a prescription can be a substantial barrier to using emergency contraception.

Briefly, the first installment of the US Plan B saga is as follows (Union of Concerned Scientists has more details and links): In 2003, over 70 medical and public-health organizations petitioned FDA to allow unrestricted over-the-counter access to Plan B. Scientists on FDA’s scientific advisory committees and professional drug review staff strongly recommended that Plan B be granted nonprescription status, but the FDA first dragged its feet on issuing a decision and then approved nonprescription status only for those age 18 and older. In 2009, a US District Court ruled that FDA’s determination had been based on politics rather than science, and ordered the agency both to reconsider its decision and to extend nonprescription access to 17-year-olds (which the agency did).

Now it’s 2011. Earlier this year, Plan B manufacturer Teva Women’s Health Inc. applied to the FDA to make the drug nonprescription for “all females of childbearing potential.” In a statement issued earlier today, FDA Commissioner Margaret Hamburg explains how the FDA came to its decision on this application:

The Center for Drug Evaluation and Research (CDER) completed its review of the Plan B One-Step application and laid out its scientific determination. CDER carefully considered whether younger females were able to understand how to use Plan B One-Step. Based on the information submitted to the agency, CDER determined that the product was safe and effective in adolescent females, that adolescent females understood the product was not for routine use, and that the product would not protect them against sexually transmitted diseases. Additionally, the data supported a finding that adolescent females could use Plan B One-Step properly without the intervention of a healthcare provider.

It is our responsibility at FDA to approve drugs that are safe and effective for their intended use based on the scientific evidence. The review process used by CDER to analyze the data applied a risk/benefit assessment consistent with its standard drug review process. Our decision-making reflects a body of scientific findings, input from external scientific advisory committees, and data contained in the application that included studies designed specifically to address the regulatory standards for nonprescription drugs. CDER experts, including obstetrician/gynecologists and pediatricians, reviewed the totality of the data and agreed that it met the regulatory standard for a nonprescription drug and that Plan B One-Step should be approved for all females of child-bearing potential.

I reviewed and thoughtfully considered the data, clinical information, and analysis provided by CDER, and I agree with the Center that there is adequate and reasonable, well-supported, and science-based evidence that Plan B One-Step is safe and effective and should be approved for nonprescription use for all females of child-bearing potential.

This is how we want the FDA to function: Scientists examine the evidence and make a decision about a drug’s approval based on that evidence. It didn’t quite work that way in 2006, but it did in 2011. The reproductive health community was ready to rejoice – but then Department of Health and Human Services Secretary Kathleen Sebelius stepped in.

In a letter to Commissioner Hamburg, Secretary Sebelius directed FDA to deny Teva’s application to remove the age restrictions for nonprescription Plan B. Her rationale is as follows:

After careful consideration of the FDA Summary Review, I have concluded that the data, submitted by Teva, do not conclusively establish that Plan B One-Step should be made available over the counter for all girls of reproductive age.

The average age of the onset of menstruation for girls in the United States is 12.4 years. However, about ten percent of girls are physically capable of bearing children by 11.1 years of age. It is common knowledge that there are significant cognitive and behavioral differences between older adolescent girls and the youngest girls of reproductive age. If the application were approved, the product would be available, without prescription, for all girls of reproductive age.

The New York Times’ Gardiner Harris reports that Secretary Sebelius does have the authority to overrule FDA, but that no other health secretary has ever used that power.

According to this summary of studies by Meredith Melnick at TIME Healthland, it sounds like FDA did consider the cognitive capabilities of 11-year-old girls:

One study reviewed by the FDA, involving 335 girls aged 12 to 17, showed that 72% to 96% of them understood the proposed Plan B One-Step package label well enough to use emergency contraception safely and effectively without consulting a doctor. Another study, involving about 300 girls aged 11 to 16 also found that they could use the drug properly on their own.

Ideally, we’d prefer that any 11-year-old girl who’s having sex – or being raped – be able to get to a doctor, or at least a trustworthy adult, and get help with securing emergency contraception and taking it correctly. But when that doesn’t happen, having an 11-year-old take emergency contraception incorrectly seems like a far better outcome than having an 11-year-old become pregnant.

Sebelius’s objection to eliminating the OTC Plan B age restriction doesn’t sound like the most scientifically grounded determination, so I have to wonder if this was politically driven. An HHS spokesperson declined to tell Business Week whether the White House played a role in the decision. In any case, we may once again see the courts make the decision – while women under 17 continue to face a barrier to emergency contraception.