Carome further points to the case of Essure, a device implanted in women's fallopian tubes as an alternative to permanent surgical sterilization. Currently marketed by Bayer, Essure was given expedited approval by the FDA in 2002 based on "two nonrandomized, nonblinded, prospective studies that lacked a [control] group and enrolled a total of 926 women," according to a report last year in the New England Journal of Medicine. Experience since then has pointed to serious potential side effects and a lack of firm evidence that the device is safer than tubal ligations, amid signs it also may be less effective at preventing pregnancy. The FDA hasn't taken Essure off the market, but it has convened a new study panel and requires a stringent warning of health risks on the label.