Volume 33, Issue 1 (January 1988)
Vaginal Fluid Zinc Concentration as a Marker for Intercourse
Zinc is present in high concentration in semen, but in low concentration in vaginal fluid. We evaluated vaginal zinc levels as a marker for intercourse by measuring precoital (>11 h after intercourse) or postcoital (<5 h after intercourse) zinc and acid phosphatase levels in 26 specimens of vaginal fluid from 18 women.
The approximate 95% reference range for zinc in precoital vaginal fluid was 1.2 to 15 μg/mL (mean 4.5), and in postcoital vaginal fluid 4.0 to 135 μg/mL (mean 24). There is an overlap between the precoital and postcoital reference ranges. Provided that the vaginal fluid zinc level is less than approximately 4.0 μg/mL or greater than approximately 15 μg/mL, vaginal fluid zinc concentration may be useful as an indicator of intercourse.