Objective: To measure the association between oral contraceptive use and the prevalence of genital warts in women.
Methods: Cross sectional case control study comparing oral contraceptive use in women with and without genital warts attending a city centre genitourinary medicine clinic controlling for recent sexual activity, the presence of other sexually transmitted infections, socio-economic class and history of pregnancy using a multivariate logistic regression model.
Results: After controlling for potential confounding variables women with genital warts were significantly more likely to be current users of the oral contraceptive pill (OR 1.7, 95% CI 1.3-2.2).
Conclusion: The study suggests that women taking the oral contraceptive may be at increased risk of presenting with genital warts. Previously published papers provide some support for this hypothesis and potential biological mechanisms are discussed.
PIP: A cross-sectional case-control study suggested that oral contraceptive (OC) users may be at increased risk of genital warts. Cases included 429 women who presented to a genitourinary medicine clinic in Edinburgh, Scotland, in 1994 with a diagnosis of first episode genital warts; 418 women presenting to this clinic during the same period with no history of genital warts served as controls. A multivariate logistic regression model controlled for recent sexual activity, the presence of other sexually transmitted diseases (STDs), socioeconomic class, and pregnancy history. Current OC use was reported by 204 cases (48%) and 153 controls (37%). The odds ratio for genital warts was 1.7 (95% confidence interval, 1.3-2.2) for OC users compared to non-users. Even when controls were introduced for genital herpes (more common among controls than cases), the odds ratio remained 1.7 (95% confidence interval, 1.3-2.1). Genital warts were more common in women in the 21-25 year age group compared to older or younger women. Women with genital warts were also less likely to report having a sexual partner in the previous 3 months and were half as likely to have a concurrent STD. Recommended, to confirm the OC-genital warts association detected in this study, are large prospective trials that control for other factors that may influence the prevalence of genital warts and act as confounders for OC use.