A large number of college women choose to delay or skip their menstruation each month by not following the instructions found on their birth-control pills or other hormonal contraceptives, a study on female students from the University of Oregon finds.

Of the 1,719 people that responded to the survey-linked e-mails, 17 percent reported altering their scheduled bleeding pattern by deviating from the contraceptive's instructions. Half of these did it out of convenience or scheduling purposes, 28.9 percent cited personal preference and 16.7 percent wanted to reduce menstrual symptoms, the study found.

The study was done by researchers from the University of Oregon, Oregon Health and Sciences University, and Eastern Michigan University, and it was published in the journal Contraception.

Among the women who delayed or skipped their cycle because of convenience or personal choice, it was found that 53 percent of them did it after consulting with nonmedical sources, such as a friend or family member, the study's news release reports.

"These findings emphasize the need for health care providers to carefully interview combined hormonal contraceptive users on how they are using their method - for example, many women may be skipping pills to extend their cycles," Christopher Minson, a human psychology professor at the University of Oregon, said in the release.

"With a greater understanding of the issues, health care providers may be able to more effectively engage in conversations with college-age women and educate them about available options," he added.

According to the news release, research suggests that reducing the frequency of menstruation is safe and even beneficial at times, but it's important to consult with health care providers who can inform these women about the best hormonal contraception regimen suited for their bodies.