Better Odds in Long-Term Contraceptives Intrauterine devices, under-the-skin implants and Depo-Provera injections - the long-acting reversible contraceptives - are much more effective in preventing pregnancy than the transdermal patch, the vaginal ring or the birth control pill, a new study reports. Researchers provided 7,486 volunteers with the contraceptive of their choice, then followed them for up to three years. Women using condoms, diaphragms and natural family planning were not included in the analysis. There were 334 unintended pregnancies. Failure rates for pills, patches and rings were more than 9 percent by the end of the study, compared with less than 1 percent for the long-acting reversible methods. The study appeared in the May 24 issue of The New England Journal of Medicine. There was no difference by age in unintended pregnancies among women using long-acting contraceptives, but young women who used the pill, patch or ring were much more likely to have an unintended pregnancy than older women using those methods. "When women say to me that they want to use the pill, I say, "That's fine, but it's 20 times less effective than an IUD," " said one of the co-authors, Dr. Jeffrey F. Peipert, of Washington University in St. Louis. "Clinicians have been reluctant to prescribe IUDs," he added, "but if we want to get a handle on unintended pregnancy in our country, we have to first offer the most effective methods."