Sentinel Injuries May Precede Severe Abuse in Infants

Steven Fox

March 11, 2013

A history of bruising or oral injury in precruising infants should raise suspicions of abuse, as such injuries are common in abused infants and rare in infants found not to be abused, according to results from a study published online March 11 in Pediatrics.

The study was conducted by Lynn Sheets, MD, from the Child Advocacy and Protection Services, Children's Hospital of Wisconsin, Milwaukee, and colleagues.

"Although it is known that relatively minor abusive injuries sometimes precede more severe physical abuse, the prevalence of these previous injuries in infants evaluated for abuse was not known," the authors write. They set out to determine how often abused infants have sustained previous "sentinel" injuries compared with infants who were not abused.

The researchers conducted a case-controlled, retrospective study of 401 infants younger than 12 months of age who had been evaluated for abuse at the Children's Hospital of Wisconsin between March 2001 and October 2011. The infants were classified by the hospital's Child Protection Team to have definite signs of abuse, intermediate signs of abuse, or no signs of abuse.

The researchers defined a sentinel injury as a previous injury, reported in the child's medical history, that was suspicious for abuse either because the infant was not yet crawling, able to pull to a stand, or walking or because the caregivers' explanation for the cause of the injury was implausible.

The investigators say that of the 200 infants who had definitely been abused, 27.5% had a previous sentinel injury. That was compared with only 8% of the 100 infants with intermediate concern for abuse (odds ratio, 4.4; 95% confidence interval, 2.0 - 9.6; P < .001).

None of the 101 nonabused infants, whose cases served as controls, had sustained a previous sentinel injury (P < .001).

The most common type of sentinel injury in children who were definitely abused was bruising (80%), followed by intraoral injury (11%) and other injury (7%).

Sentinel injuries occurred during early infancy, the researchers say: 66% at younger than 3 months of age and 95% by the time they had reached 7 months of age.

Further, the investigators say, medical providers were reportedly aware of sentinel injuries in 41.9% of the cases.

One the basis of their findings, the authors conclude, "Detection of sentinel injuries with appropriate interventions could prevent many cases of abuse."

Funding for the medical student summer research stipends and for data analysis by Quantitative Health Sciences was provided by the Child Abuse Prevention Fund of Children's Hospital of Wisconsin, the Wisconsin Children's Trust Fund, and the Department of Pediatrics at the Medical College of Wisconsin. Dr. Sheets has provided paid expert testimony for prosecution and defense attorneys in cases of alleged child physical maltreatment. The other authors have disclosed no relevant financial relationships.

Pediatrics. Published online March 11, 2013.