The use of post-mortem lividity to determine sleep position in sudden unexpected deaths in infancy

To compare parental reports of position found in sudden unexpected deaths in infancy (SUDI) to autopsy reports of lividity and to more accurately classify infant sleep position.

Cases of SUDI in Queensland between 2010 and 2014 were reviewed to determine the position in which infants were reported to have been placed and found. This was compared to the distribution of post-mortem lividity at autopsy. Evidence of lividity present during early death scene investigation was also recorded.

There was a discordance between the position an infant was reported to have been found and the position of lividity at autopsy in 22/228 SUDI (9.6%). All infants had anterior lividity despite 13 reportedly found supine, three on their side and six in an unknown position. Using anterior lividity at autopsy to change the position found increased the proportion of prone infants from 37.7% to 47.4%. In 47.8% cases, anterior or lateral lividity reported at the scene was no longer present at autopsy.

Previously published odds ratios may have underestimated the risk of sudden infant death associated with prone sleep position. SUDI death scene investigation protocols should require photographic documentation of lividity prior to transporting an infant.