A Spanish research team found that women who use IUDs are just as likely as others to become infected with HPV, the Human Papillomavirus. But they were almost 50 percent less likely to get cervical cancer, which is most commonly caused by HPV. Cervical cancer is the second most frequent kind of cancer in women.
The researchers of the study published in the Lancet Oncology journal on Tuesday, who studied 20,000 women, are not sure what causes the reduction in risk. Some of the theories are that the process of placing an IUD or removing one can destroy pre-cancerous cells, or that the presence of a birth control coil triggers an immune response in the body. Xavier Castellsague of the Catalan Institute of Oncology in Barcelona said: "It was a little unexpected. The data before we did this study were very inconsistent, so we didn't expect to find such a strong association with this protective effect."
He added: "IUDs are not inert devices. Our speculation is that they act as a foreign body and stimulate inflammatory changes that prevent the HPV infection from persisting and progressing to more advanced stages." The amount of time a woman had a coil inserted did not have much relevance, the researchers noted. The risk of developing cervical cancer was reduced by almost half within the first year of having an intrauterine device placed, and the protective effect lasted for a decade, according to the findings of this study.