Post-mortem Investigation of Sudden Unexpected Death in Infancy: Role of Autopsy in Classification of Death

Abstract

Sudden unexpected deaths in infancy (SUDI) represent the commonest group of post-neonatal childhood deaths. Pathologists in the UK are currently rec- ommended to follow the Kennedy when performing such autopsies. This suggested protocol is primarily based on practice from expert opinion and the approach to the post-mortem examination has changed little over recent decades. The identification of specific medical causes of death at autopsy in SUDI has slightly improved in recent years, but around two-thirds of cases remain unexplained, being classified as SIDS or SUDI according to local protocols and circumstances. Current protocols include the autopsy with macroscopic examination of organs, but in the majority of cases in which a cause of death is identified, the diagnosis is based on a combination of ancillary investigations including histological examination and microbiological findings, which are mandatory studies in these infant deaths. However, with increasing evidence regarding the relative frequency with which the various components of the autopsy provide information regarding the cause of death, and recognition that immunological responses and/or bacterial products may be of increasing importance, alternative and/or additional diagnostic techniques are required which may result in modified evidence-based autopsy protocols. The aim of this article is to review the current evidence for protocols of post-mortem inves- tigations of SUDI, with particular emphasis on features which may distinguish natural from unnatural deaths, and to evaluate the approach to investigations which maximise the likelihood of identifying natural causes of death. The article will not discuss issues related to non-accidental or inflicted injury, which remain complex and beyond the scope of this review.