Postmortem diagnostics in sudden unexpected death in infants and children: use and utility

Sudden unexpected death in infants (SUDI) and children (SUDC) requires thorough investigation to identify causes and prevention strategies. In the Netherlands, these deaths are investigated using the standardized postmortem evaluation of sudden unexpected death in infants and children (PESUDIC) procedure. This study examines the use of various diagnostic tests within PESUDIC and their effectiveness in determining causes of death. This observational study included infants and children who died suddenly and underwent the PESUDIC procedure from 2016 to 2022. Standardized data on medical history, postmortem examinations, and diagnostic outcomes were collected. Findings were classified by consensus of two experts as "contributory" if they supported the cause of death and "decisive" if they were leading for determination. A total of 275 cases were included. Median age was 13 months (IQR 3.5-73.3). Fifty-nine percent were boys. Over 95% of cases had a medical history, postmortem physical examination, biochemical, and microbiological testing available. Total body postmortem CT and/or MRI was done in 93% (n = 255) and autopsy in 62% (n = 171). The cause of death was determined in 193 (70%). History, imaging, and autopsy provided contributory results in 50% (n = 137/275), 40% (n = 103/255), and 67% (n = 115/171) of applicable cases, respectively. More than two different tests showed contributory findings in 52% of diagnosed cases. Autopsy and microbiological testing had decisive findings most often: in 83/171 and 44/265 cases respectively.

A routinely performed wide array of postmortem investigations has additional value to an autopsy for identifying the cause of death in SUDI and SUDC. A thorough SUDY investigation should therefore minimally include an autopsy, microbiological testing, and whole-body imaging.

• A thorough postmortem investigation into the cause of sudden death in infants and children can provide an explanation of the death and identify potential preventable causes.

• A thorough postmortem investigation for sudden unexpected death in infants and children should minimally include an autopsy, microbiological testing and whole-body imaging.