Having a higher number of lifetime ovulatory cycles and starting your period at a younger age may increase your risk of death from ovarian cancer, according to new research.

U.S. researchers analyzed data on more than 410 women, aged 20 to 54, who ad ovarian cancer. Those who had the highest number of lifetime ovulatory cycles had a 67 percent greater chance of dying during the follow-up. Women who had their first menstrual cycle before age 12 were 51 percent more likely to die from cancer than those who were 14 or older.

Researchers believe the surge of hormones brought on by ovulation, or damage to the cells that occurs during ovulation, may be associated with more aggressive tumors.

Authors of the study say there were limitations including the average age of these patients being younger than the typical age of ovarian cancer patients. They note more research is needed to learn how hormone exposure can change the biology of ovarian cancer and make it more aggressive.