Persistence of vaginal spermatozoa as assessed by routine cervicovaginal (Pap) smears.

Retrospective review of cervicovaginal (Pap) smears of women with known sexual histories affords an opportunity to assess the potential for postcoital sperm recovery for large numbers of individuals. This study reviewed 542 individuals' Pap smears with accompanying sexual histories. Three hundred forty-nine respondents reported at least one act of sexual intercourse during the five days preceding the Pap smear. Unlike a previous report, the current study showed very poor sperm recovery (maximum of 25% during the first postcoital day). The observed results roughly correlate with the incidence of sperm noted on screening of large numbers of routine clinical Pap smears in a private reference laboratory. Routine Pap smears can detect sperm but do not appear to be an ideal method to substantiate recent sexual intercourse.