Classification of sudden infant death (SID) cases in a multidisciplinary setting. Ten years experience in Styria (Austria).

Objective: Sudden infant death syndrome (SIDS) remains a challenge for health professionals despite decreasing rates in recent years. The figures for different areas and time periods are hardly comparable, because of differences in postmortem investigations and classification criteria. In 1992, the European Society for the Study and Prevention of Infant Deaths (ESPID) proposed a classification for any sudden and unexpected death in infancy. This proposal has been used in our study since 1993 to better classify sudden infant death (SID) cases.

Method: 56 consecutive SID cases observed between 1993 and 2002 in Styria, the south-eastern province of Austria, were analysed by a multidisciplinary team of health professionals. The study group consisted of pediatricians, forensic pathologists, pathologists, psychologists, nurses, members of the parents' association and health authorities. SID cases were analysed with regard to potential risk factors during pregnancy and early life, the circumstances of death (death scene) and post-mortem findings. From the latter, every SID was classified as either 1) classic SIDS, 2) borderline SIDS, 3) non-autopsied SID or 4) explained death.

Results: Of the 56 SID cases, 22 were assigned to category 1, 19 to category 2, four to category 3, and in 11 cases death could be explained by major post-mortem findings. For 17/22 cases in category 1 and 11/19 cases in category 2, the death scene investigation showed the typical risk profile of manner of bedding and/or environmental conditions. In three cases, child abuse or infanticide was considered possible but could not be proven despite careful autopsy. In recent years, SIDS incidence in Styria has decreased to approximately 0.18/1,000 live-born infants, and the few deaths still occurring mainly present with the typical risk profile.

Conclusion: An extensive analysis of SID events is a prerequisite for reliable and comparable SIDS statistics. Our data show that in several SID cases careful post-mortem examinations led to an explanation of death. In other cases, minor alterations may have contributed to the lethal event. These findings should therefore be considered in the classification of SIDs. The ESPID classification of 1992 appears to be very useful for this purpose and its use may therefore be recommended.