Women with certain types of human papilloma virus (HPV) infection run the risk of developing CIN - cervical intraepithelial neoplasia, a type of pre-cancer. However, contrary to previous concerns, their risk is not affected if they use hormonal contraceptives, or by their history of pregnancy and childbearing, researchers have found.

Previous studies have suggested an increased risk of CIN with long-term oral contraceptive use and having more than one child, the investigators explain in the International Journal of Cancer, but such studies did not account for the possible confounding effect of cancer-related HPV infection.

Dr. Philip E. Castle from National Cancer Institute, Bethesda, Maryland and colleagues investigated the development of CIN in young women who tested positive for these types of HPV and had minimally abnormal Pap smears.

Among these women, the likelihood of finding CIN was no higher for current or former oral contraceptive users than for those who had never used the Pill, the team reports.

There was a marginal association with CIN and the current use of injectable or former Norplant use.

The number of pregnancies and children a woman had were not associated with being infected with the cancer-related strains of HPV, or with CIN in those who did have these infections, the researchers note.

SOURCE: International Journal of Cancer, December 20, 2005.