Impact of mechanical force on posterior hymen - Implications for sexual abuse injury interpretations.

BACKGROUND: Residual anogenital findings following sexual abuse are rare. There is a need for further understanding of the interpretation of hymenal findings.

OBJECTIVES: This study evaluates which is more significant with respect to posterior hymenal tissue morphology - previous consensual penile vaginal penetrations or vaginal delivery.

DESIGN: A post hoc study comparing nulliparous and parous hymen in heterosexually active female volunteers, with the focus on healed hymenal defects. Adult posterior hymen configuration was evaluated using labial separation or traction. When needed, the hymenal status was evaluated using a swab. A colposcopy with photography was used for documentation. Experts reviewed all taken photographs and recorded the posterior hymenal defects. Photographs were analyzed to determine the level of agreement.

PARTICIPANTS: Eighty-seven adult female volunteers were recruited to participate in the study by a personal invitation to a gynecological examination to document anogenital findings. The examination was performed following consensual vaginal intercourse. Age ranged from 20 to 53 (median 26.6years).

RESULTS: Single site posterior hymenal transections were significantly more likely in the nulliparous volunteers, compared to the parous volunteers (22/51, 43.1% vs. 4/36, 11.1%, p<0.001). A deep notch, which extends nearly to the base of the hymen was detected in one (2.0%) sexually active nulliparous volunteer, and surprisingly two (3.9%) volunteers had a single, more superficial hymenal notch, that is not considered a sign of previous vaginal penetration. The width of the ridge of the posterior vaginal wall in the vestibule was measured from the anterior part of the navicular fossa to the base of the hymen. The mean width of the ridge of the posterior vaginal wall was 3.1mm (SD2.2, range 0-8) in the photos of 41 nulliparous volunteers. The prevalence of 'double leaf hymen' was 2/87 (2.3%). The inter-rater reliability with a Kappa score of 0.69 indicated strong agreement.

CONCLUSION: The myth "hymen is present only in virgins" has now been invalidated. The absence of posterior hymen increases delivery by delivery in adult female volunteers. The space between the anterior part of the navicular fossa and the base of hymen, 'the ridge of the posterior vaginal wall' in the vestibule was evaluated for the first time among studies evaluating hymenal status. Careful assessment of the ridge of the posterior vaginal wall is needed to avoid misinterpretations when evaluating the depth of a hymenal defect.