Oral contraceptives and human papillomavirus infection in cervical intraepithelial neoplasia.

We report about 142 patients from whom colposcopically directed cervical punch biopsies were taken which showed condylomatous lesions with or without cervical intraepithelial neoplasia (CIN). Fifty-six (39.4%) of these women used oral contraceptives (OC) for at least two years before examination. We used DNA in situ hybridization on all biopsies for detection of human papillomavirus (HPV)-DNA. Among OC users a significant trend towards higher HPV infection rates in high grade CIN (odds ratio 2.9, P less than 0.05) was found, whereas non-users of oral contraceptives had the highest HPV infection rate in condylomatous lesions without CIN (odds ratio 0.5, P less than 0.05). Thus in OC users HPV infection was about 24 times more likely in CIN III as in condyloma, while among non-users the trend was the other way round (7-fold likelihood of HPV positivity in condyloma compared to CIN III). Other known risk factors for cervical carcinoma did not influence HPV infection rates in either group.