Air embolism as evidence of antemortem sexual activity

In the forensic autopsy examination of sexual assault cases, two essential questions must be addressed: whether sexual activity occurred, and whether sexual activity occurred antemortem or postmortem. However, confirming sexual activity can be challenging, particularly when the activity may not have involved penis-in-vagina intercourse and when semen detection results are negative. Moreover, determining whether the sexual activity took place antemortem or postmortem solely through forensic autopsy can be difficult. Here, we report a forensic autopsy case of sexual homicide with air embolism, suggesting antemortem sexual activity. Histopathological observations revealed that the origin of right ventricular air embolism was uterine vein exposure, allowing a significant amount of air to enter the endometrial cavity and eventually the bloodstream through venous exposure. Multiple squamous epithelial cells were identified in the endometrial cavity, indicating that an external force had pushed detached epithelial cells from the cervix or vagina into the uterine cavity. The present case highlights the importance of considering air embolism in suspected sexual assault cases.