The Association between the Interval of Sexual Assault to Collection of Specimen and Detection of Spermatozoa in the Vagina

Abstract

The Association between the Interval of Sexual Assault to Collection of Specimen and Detection of Spermatozoa in the Vagina

Rangsima Taepaiboon MD, LLB

Unit of Forensic Medicine , BMA General Hospital

Objective: To determine the association between the interval of sexual assault to collection of specimen and the detection of spermatozoa in the vagina.

Study design: Cross sectional study.

Subjects: 97 sexually assaulted women who were sent by the police officers for a forensic medical investigation of sexual assault at BMA General Hospital during January 2002 and May 2008.

Methods: Medical records and forensic evidence reports of the sexually assaulted women in BMA General Hospital during the study period were reviewed. Data collections from these records as well as the results from the Serology Laboratory for forensic evidence, Siriraj Hospital were taken.

Main outcome measures: Interval between sexual assault to vagina specimen collection, detection of spermatozoa in the vagina.

Results: From 97 sexually assaulted victims, sperms were found in the vagina of 66 women (68%). Women who had the examination within 24 hours had the highest positive test for sperm, 29/31 women (93.5%). The positive findings declined as the intervals between sexual assault and vagina specimen collections were longer. Sperms were found in 21/37 women (56.8%), 9/16 (56.3%) women and 7/13 women (53.8%), who were examined within 1-3 days, 3-7 days and after 7 days respectively. Statistical significant association between the interval of sexual assault to collection of specimen and detection of spermatozoa in the vagina was found.

Conclusion: The appropriate time that the sexually assaulted victims should consult for the forensic evidence is within 24 hours to yield the highest detection rate of spermatozoa.

Vajira Med J 2008 ; 52 : 219-227