The Harvard Medical School, Boston, researchers found that the longer a woman uses the contraceptive pill, the less likely she is to develop the disease, with the period of five to ten years giving the best protection when she stops using it, reports the Daily Mail.
The 28-year study into contraceptive methods and the disease, which involved more than 100,000 women, allowed the researchers to inspect the long-term effects of different contraceptive methods.
Disturbingly, the researchers found that the old coil, an intrauterine device, or IUD, fitted in the 1970s and 1980s, increased the chances of ovarian cancer by 76 per cent.
The researchers also found that women who were infertile had a 36 per cent greater risk when compared to those who were fertile. The findings also suggested that sterilisation protected women from the cancer. Those who were sterilised had a 34 per cent less chance of developing it than those who had not been sterilised.
But the most remarkable finding was the long-term protective effect of oral contraceptives indicating that the longer a woman used the Pill, the more protection she got when she ultimately stopped.
Dr Shelley Tworoger, who led the research, said oral contraceptives emerge to protect against ovarian cancer for up to 20 years after a women has stopped using them, however, she warned, "Oral contraceptives are usually taken in young adulthood, but ovarian cancer incidence peaks after menopause. So women may not maintain the protective effect of oral contraceptive use to the time of highest incidence."
Dr Tworoger believes doctors should keep on examining the disease saying, "future studprotectiveies should continue to examine the potential waning effect of oral contraceptives with longer time since last use."
A spokesman for fpa, formerly the Family Planning Association, said the study confirmed the consequence of oral contraception-against ovarian cancer.
"The Pill has many health benefits other than contraception. It protects against cancer of the ovaries, of the womb and against colon cancer. It can also protect against pelvic inflammatory disease. So if women are at risk from it, they may wish to use the Pill in addition to their normal contraceptive methods," the spokesman said.
The study is published in the American Journal of Epidemiology.