How Often Adult Sexual Assault Exams Show Genital Injury

In published clinical series, most adult women examined after reporting a sexual assault have no visible genital injury. Reported genital or genital-anal injury rates in these studies range from about 20% to 25% of complainants, with some subgroups showing higher rates depending on age, prior sexual experience, and how soon the exam occurred after the assault. In one comparison study, genital injury also occurred after consensual intercourse, at a lower rate than after reported non-consensual intercourse (McLean 2011). These numbers describe examination findings in specific study populations; they do not by themselves establish whether consent was present or absent in any individual case.

Several peer-reviewed studies have looked at this question directly. In a series of 819 females age 15 and older presenting to an urban emergency department after sexual assault, 52% had general body trauma, 20% had genital-anal trauma, and 41% had no injury at all (Sugar 2004). General body trauma in that series was associated with being hit or kicked, attempted strangulation, oral or anal penetration, and assault by a stranger. Genital-anal injury was more frequent in complainants younger than 20 or older than 49, in those without prior vaginal intercourse, in exams performed within 24 hours, and after anal assault.

A separate study compared genital injury rates between women reporting non-consensual and consensual intercourse. Among 500 adult complainants of single-assailant penile-vaginal rape, 22.8% had a genital injury visible within 48 hours, while 77% had none. In a comparison group of 68 women examined after recent consensual intercourse, 5.9% had a genital injury. Complainants were about three times more likely to have a genital injury than the consensual-intercourse group, a difference the authors found statistically significant. Injury was more likely when the assailant was known to the complainant (McLean 2011).

A larger Australian cross-sectional study of 1,266 women examined at a sexual assault resource centre found genital injury in 24.5% of those reporting completed vaginal penetration, and anal injury in 27.0% of those reporting completed anal penetration. Among women with no prior sexual intercourse, the genital injury rate rose to 52.1%. Injury was less likely with sedative use and with delayed examination. The authors noted that genital injuries were absent in a large proportion of women regardless of prior intercourse status (Zilkens 2017).

Adolescent complainants have been studied as a separate population. In a series of 224 female adolescents aged 12 to 17 examined after an alleged non-consensual intercourse, 51% had a non-genital injury, generally minor. Genital injury was present in 53% of those without prior intercourse and 32% of those with prior intercourse, though only 32% of the no-prior-intercourse group had genital injury of the type that would leave permanent evidence of penetration. The authors concluded that genital and body injuries are not routinely found in adolescents after such an allegation, even in those without previous sexual experience, and that absence of injury does not exclude the possibility of intercourse, with or without consent (White 2006).

What this does and does not mean

Injury-rate figures are specific to the population and methods of each study. They vary with the age of the complainants, whether the assailant was known or a stranger, the interval between assault and examination, and the type of penetration involved. A rate from one series should not be applied as a fixed probability to a different case.

The presence of genital injury does not by itself prove the absence of consent. The McLean 2011 comparison found genital injury after consensual intercourse as well, at a lower but non-zero rate. Injury reflects tissue trauma; it does not on its own establish the circumstances under which that trauma occurred.

The absence of genital injury does not by itself prove consent, and it does not establish that no assault occurred. In every series described here, a substantial share of women reporting non-consensual intercourse had no genital injury on examination.

Adolescent findings are reported separately because injury patterns and rates differed by prior sexual experience in that population, and the adolescent series is smaller and drawn from a different clinical setting than the adult series.

In casework, these findings are relevant to how genital examination results are interpreted. An exam finding, whether positive or negative, is one piece of evidence to be weighed alongside history, other injury findings, and the rest of the record. It does not stand alone as proof of consent or of assault.

The studies cited below are indexed in PubMed; DOI links are provided.

References

1. Sugar NF, Fine DN, Eckert LO. Physical injury after sexual assault: findings of a large case series. Am J Obstet Gynecol. 2004;190(1):71-76. doi:10.1016/s0002-9378(03)00912-8
2. McLean I, Roberts SA, White C, Paul S. Female genital injuries resulting from consensual and non-consensual vaginal intercourse. Forensic Sci Int. 2011;204(1-3):27-33. doi:10.1016/j.forsciint.2010.04.049
3. White C, McLean I. Adolescent complainants of sexual assault; injury patterns in virgin and non-virgin groups. J Clin Forensic Med. 2006;13(4):172-180. doi:10.1016/j.jcfm.2006.02.006
4. Zilkens RR, Smith DA, Phillips MA, Mukhtar SA, Semmens JB, Kelly MC. Genital and anal injuries: a cross-sectional Australian study of 1266 women alleging recent sexual assault. Forensic Sci Int. 2017;275:195-202. doi:10.1016/j.forsciint.2017.03.013