Washington ? Making emergency contraception available without a prescription in Britain did not lead women there to rely on it rather than other birth control methods or to an increase in unprotected sex, a new study has found.

The three-year study of more than 20,000 women found that over-the-counter availability had little real-world effect at all. Roughly the same percentage of women used it before and after it became more easily available in January 2001 – about 8 percent annually.

The researchers concluded that as a result, fears that non-prescription emergency contraception would change contraceptive practices for the worse were unfounded, as were hopes that it would reduce the number of unwanted pregnancies.

The study was published on the online version of the British journal BMJ (formerly the British Medical Journal).

The question of whether emergency contraception should be available without a prescription has become a hot-button and political issue in the United States, with social conservatives arguing that it will encourage sexual promiscuity and reproductive rights advocates saying it will enable women to better protect themselves against unintended pregnancies.

In 2003, a Food and Drug Administration advisory panel voted 23-4 to recommend making the Plan B brand of emergency contraceptive available without prescription, but the agency rejected the proposal last May. The makers of Plan B, Barr Laboratories, revised the application and resubmitted it, but the agency missed its January deadline for acting on it.

The issue has now been raised in the Senate confirmation of Lester Crawford, nominated by President Bush to become permanent FDA commissioner. Sens. Hillary Clinton, D-N.Y., and Patty Murray, D-Wash., have accused the administration of politicizing the Plan B application and have placed a hold on Crawford’s nomination until the FDA makes a decision.

The authors of the new study, conducted by researchers at the Imperial College Faculty of Medicine in London and funded by the British Office of National Statistics, wrote that their work had “important policy implications.”

They concluded that women prefer obtaining emergency contraception over-the-counter rather than from a physician, that the cost ($40 U.S.) appears to be a barrier for some women, and that the proportion of women using emergency contraception – and those using it more than once a year – did not increase following the policy change.

“Given the apparent absence of negative consequences, and the fact that many women clearly prefer to buy (emergency contraception) over the counter, our study supports the case for lifting the ban on over-the-counter sales in the United States and other countries,” the authors, led by professor of primary care Azeem Majeed, wrote.

The study found that the concerns of American social conservatives regarding Plan B were unwarranted, but it did not support the argument of many advocates of the switch, either.

The advocates have said that non-prescription emergency contraception would lead to a reduction in unwanted pregnancies and possibly a reduction in abortions. Because the usage of emergency contraception did not increase, however, the researchers concluded that easier availability is “unlikely to have affected unwanted pregnancies.”