IUDs lower risk of getting cervical cancer
The risk of cervical cancer in women with IUDs was one-third lower than women without them, said the review in the journal Obstetrics and Gynecology.
"The pattern we found was not subtle at all," said lead author Victoria Cortessis, associate professor of clinical preventive medicine at the Keck School of Medicine, part of the University of Southern California.
"The possibility that a woman could experience some help with cancer control at the same time she is making contraception decisions could potentially be impactful."
Researchers are not sure why the risk of cervical cancer drops so much, but one theory is that the devices stimulate an immune response that helps fight off cancer-causing infections like the human papillomavirus.
Another possibility is that when women have the devices removed, precancerous cells are scraped away that might otherwise grow into tumours.
Cervical cancer kills about 270,000 women a year, according to the World Health Organisation.