The Prentif cervical cap and Pap smear results: a critical appraisal

An analysis from a randomized study has suggested that a larger percentage of Class III Pap smears appears among Prentif cervical cap users three months after initiation of use of the method than among diaphragm users. This suggestion has been the basis of a U.S. Food and Drug Administration (FDA) requirement that women seeking to use the cap have Pap smears taken before initiating use and again after three months of use. The data from the pivotal randomized study are reanalyzed here. No significant differences exist in the distributions of smears between cap and diaphragm users at three months or throughout the first year. The majority of cap users with "Class III" smears at three months did not have even mild dysplasia when subsequently evaluated by biopsy or colposcopy. This was also the case for diaphragm users classified as having grade III smears at three months. Other studies of the Prentif cap have not found conversions to Class III smears at one year. The requirement of a 3-month Pap smear is not only economically burdensome to potential users of the cap but appears to be without firm foundation in the original data or in our current views of cervical carcinogenesis.