Does oral contraceptive pill increase the risk of abnormal Pap smear?

Background: It is noted that oral contraceptive pills increase the risk of abnormal Pap smear but results have been inconsistent across the populations.
Objective: This study aimed to evaluate the association between oral contraceptive pill (OCP) consumption and abnormal Pap smear in women who referred to Shahid Sadoughi and Madar hospitals in Yazd.
Materials and Methods: A cross sectional descriptive study was carried out and a database of all Pap smear reports from 2009-2011 at Cytopathology Department of Shahid Sadoughi and Madar hospitals in Yazd, Iran was reviewed. A total number of 1286 women with history of OCP consumption were selected as the case group and 1218 women applying other contraceptive methods were selected as control group for evaluation. Both case and control groups were matched by age, parity and socioeconomic status. All of the women in this study maintained a single partner as their husband and none of them were considered as smokers. The duration of OCP use was at least 5 years.
Results: Abnormal Pap smear results were observed in 0.4% of cases and 0.2% of controls. There was no significant association between OCP consumption and abnormal Pap smear (p=0.727).
Conclusion: Our findings did not show any specific association between OCP consumption and abnormal Pap smear results. In addition, the number of abnormal Pap smears in women who consumed OCP was lower than that of western countries. More prospective studies are required.