The contraceptive coil may slash the risk of cervical cancer by a third, according to new research.
Considered a safe and highly effective contraception method, the study suggests intrauterine devices, know as IUDs or coils, may also be "quietly offering protection" against the third-most common cancer in women worldwide.
American researchers linked use of the coil to a "dramatic decrease" of a third in the incidence of cervical cancer.
Their review, published in the journal Obstetrics and Gynaecology, is the first to combine figures from multiple studies on IUDs and cervical cancer.
The analysis included figures from 16 observational studies involving more than 12,000 women worldwide.
The results showed that in women who used an IUD, the incidence of cervical cancer was a third lower.
Study lead author Doctor Victoria Cortessis, of The Keck School of Medicine of the University of Southern California, said: "The pattern we found was stunning. It was not subtle at all.
"The possibility that a woman could experience some help with cancer control at the same time she is making contraception decisions could potentially be very, very impactful."
The number of women diagnosed with cervical cancer is steadily rising, according to World Health Organisation (WHO) figures.
Around 528,000 women were diagnosed with cervical cancer worldwide in 2012, and 266,000 women died from the disease.
By 2035, the WHO projects that those numbers will climb to more than 756,000 and 416,000, respectively.
For women in developing countries, where cervical cancer prevention resources such as the human papillomavirus (HPV) vaccine or regular cervical screenings are scarce, Dr Cortessis says a contraceptive that offers protection against cervical cancer could have a "profound" effect.
She added: "A staggering number of women in the developing world are on the verge of entering the age range where the risk for cervical cancer is the highest - the 30s to the 60s.
"Even if the rate of cervical cancer remains steady, the actual number of women with cervical cancer is poised to explode.
"IUDs could be a tool to combat this impending epidemic."
The researchers said that while gynecologists shouldn't begin recommending the coil for protection against cervical cancer quite yet, it could be on the horizon.
Dr Cortessis said understanding the mechanism of action behind the protective effect of IUDs is the next logical step,
Some scientists believe that the placement of an IUD stimulates an immune response in the cervix, giving the body an opportunity to fight an existing HPV infection that could one day lead to cervical cancer.
The research team said that another possibility is that when an IUD is removed, some cervical cells that contain HPV infection or precancerous changes may be scraped off.
Study coauthor Dr Laila Muderspach, chair of obstetrics and gynecology at the Keck School, added: "If we can demonstrate that the body mounts an immune response to having an IUD placed, for example, then we could begin investigating whether an IUD can clear a persistent HPV infection in a clinical trial.
"The results of our study are very exciting. There is tremendous potential."