Absence of hymenal trauma does not exclude child sexual abuse: Forensic significance of a study-defined highly elastic/dilated hymenal phenotype.

BACKGROUND

The absence of detectable genital injury is a frequent source of medico-legal misunderstanding in child sexual abuse (CSA) evaluation. Reported vaginal penetration may occur without documented traumatic hymenal findings, and marked hymenal distensibility may be one factor associated with this absence.

OBJECTIVE

To evaluate whether a study-defined highly elastic/dilated hymenal phenotype is associated with a lower prevalence of documented traumatic hymenal findings among girls reporting vaginal penetration.

METHODS

This retrospective observational analytical study included 192 girls younger than 18 years evaluated for alleged CSA with documented reported vaginal penetration between November 2022 and December 2025. The study-defined highly elastic/dilated hymenal phenotype was identified by the combined presence of marked distensibility of the hymenal free edge, a hymenal/vaginal opening of approximately 3 cm or greater during examination, and easy visualization of vaginal rugae following gentle traction. Classification in the phenotype group required confirmation by a second experienced forensic examiner. Group comparisons and multivariable logistic regression were performed.

RESULTS

The study-defined phenotype was identified in 35/192 (18.2%) girls. Documented traumatic hymenal findings were present in 5/35 (14.3%) girls with the phenotype and 74/157 (47.1%) girls with other hymenal configurations (p < 0.001). No detectable traumatic hymenal finding was documented in 85.7% and 52.9%, respectively. After adjustment for age, examination within 30 days, reported penile penetration involvement, and repeated abuse, the study-defined phenotype remained associated with lower odds of a documented traumatic hymenal finding (aOR = 0.15, 95% CI 0.05-0.42; p < 0.001).

CONCLUSION

Among girls reporting vaginal penetration, the study-defined highly elastic/dilated hymenal phenotype was associated with substantially lower odds of documented traumatic hymenal findings. These findings do not establish a causal or protective mechanism. Absence of detectable hymenal trauma should not be used to exclude reported vaginal penetration or CSA, and forensic interpretation should remain multidisciplinary.