Whatever the mechanism, it seems to work quickly. Women who used an IUD for less than a year were no more likely to be diagnosed with cervical cancer than women who’d had an IUD implanted for several years.
There are two kinds of IUD available in the U.S., both of which are T-shaped and made from molded plastic. One uses copper as a contraceptive, and the other prevents pregnancy by releasing the hormone progestin into the uterus. Both are extremely effective forms of birth control, but because the study did not include data on the type of IUD used, the authors were unable to assess whether one type of IUD is more likely than another to lower the risk of cervical cancer.
The new findings do not mean that women worried about cervical cancer should be fitted for an IUD, says Karl Ulrich Petry, MD, a gynecologic oncologist at the Klinikum Wolfsburg, in Germany.
Petry, who wrote an editorial accompanying the study, points out that HPV testing and Pap smears already reduce the risk of cervical cancer by 80% to 90%.
“Women in countries with screening programs are well protected,” he says. “Cervical cancer is a preventable disease—we have more tools to prevent this cancer than any other malignancy in humans. Women should really use [HPV] vaccine and screening to protect themselves from this cancer.”