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

Sudden Unexpected Death in Infancy [SUDI]: What the clinician, pathologist, coroner and researchers want to know

The loss of an apparently healthy infant is confronting for any family, puzzling for a clinician and challenging for the pathologist charged with the task of demonstrating a cause for death. The term "cot death" evolved to "sudden infant death syndrome" [SIDS] and now "sudden unexpected death in infancy [SUDI]" as the epidemiology and pathology of infant death changed. Community interventions were successful in changing sleep practices for young babies. The current research focus is on understanding genetic predispositions to unexpected death in early childhood. Whilst much has been achieved in reducing the infant mortality rate from SUDI by between 50%, and 80% in some countries, over the last 30 years, there remain challenges for improving rates of accurate diagnosis and reaching out to more vulnerable families with clearly modifiable risk factors for SUDI. These challenges directly involve the clinician through taking a systematic and detailed history and better standardised death scene evaluations with specifically accredited assessors. Better knowledge regarding circumstances of SUDI cases will help Coroners and researchers provide answers for grieving families now, and in the future contribute to further reductions in the rate of SUDI in communities across the world.

Prevalence of risk factors for sudden infant death among Indigenous and non-Indigenous people in Australia

AIM

To examine differences in the prevalence of risk factors for sudden unexpected death in infancy (SUDI) between Aboriginal and Torres Strait Islander and non-Indigenous infants.

METHODS

A retrospective cohort study of SUDI in Queensland during 2010-2014 examined exposure to SUDI risk factors, to identify factors accounting for higher SUDI mortality among Indigenous infants. A multistage algorithm was applied to linked data to determine Indigenous status.

RESULTS

There were 228 SUDI, of which Indigenous infants comprised 26.8%. The Indigenous SUDI rate was 2.13/1000 live births compared to 0.72/1000 for non-Indigenous. The disparity between Indigenous and non-Indigenous SUDI was accounted for by surface sharing (OR = 2.93 95% CI = 1.41, 6.07), smoking (OR = 2.49, 95% CI = 1.13, 5.52), and a combination of background antenatal and sociodemographic factors (inadequate antenatal care [OR = 6.93, 95% CI = 2.20, 21.86], young maternal age at first birth [OR = 4.02, 95% CI = 1.49, 10.80] and outer regional [OR = 3.03, 95% CI = 1.37, 6.72] and remote locations [OR = 11.31, 95% CI = 3.47, 36.83]).

CONCLUSION

Culturally responsive prevention efforts, including wrap-around maternity care and strategies that reduce maternal smoking and promote safer yet culturally acceptable ways of surface sharing, may reduce Indigenous SUDI mortality.

National Variations in Recent Trends of Sudden Unexpected Infant Death Rate in Western Europe

OBJECTIVE

To study recent epidemiologic trends of sudden unexpected death in infancy (SUDI) in Western Europe.

STUDY DESIGN

Annual national statistics of death causes for 14 Western European countries from 2005 to 2015 were analyzed. SUDI cases were defined as infants younger than 1 year with the underlying cause of death classified as "sudden infant death syndrome," "unknown/unattended/unspecified cause," or "accidental threats to breathing." Poisson regression models were used to study temporal trends of SUDI rates and source of variation.

RESULTS

From 2005 to 2015, SUDI accounted for 15 617 deaths, for an SUDI rate of 34.9 per 100 000 live births. SUDI was the second most common cause of death after the neonatal period (22.2%) except in Belgium, Finland, France, and the UK, where it ranked first. The overall SUDI rate significantly decreased from 40.2 to 29.9 per 100 000, with a significant rate reduction experienced for 6 countries, no significant evolution for 7 countries, and a significant increase for Denmark. The sudden infant death syndrome/SUDI ratio was 56.7%, with a significant decrease from 64.9% to 49.7% during the study period, and ranged from 6.1% in Portugal to 97.8% in Ireland. We observed between-country variations in SUDI and sudden infant death syndrome sex ratios.

CONCLUSIONS

In studied countries, SUDI decreased during the study period but remained a major cause of infant deaths, with marked between-country variations in rates, trends, and components. Standardization is needed to allow for comparing data to improve the implementation of risk-reduction strategies.

Applying a Social Exclusion Framework to Explore the Relationship Between Sudden Unexpected Deaths in Infancy (SUDI) and Social Vulnerability

Background: Sudden Unexpected Death in Infancy (SUDI) is a leading cause of preventable infant mortality and strongly associated with social adversity. While this has been noted over many decades, most previous studies have used single economic markers in social disadvantage analyses. To date there have been no previous attempts to analyze the cumulative effect of multiple adversities in combination on SUDI risk.

Methods: Based on sociological theories of social exclusion, a multidimensional framework capable of producing an overall measure of family-level social vulnerability was developed, accounting for both increasing disadvantage with increasing prevalence among family members and effect of family structures. This framework was applied retrospectively to all cases of SUDI that occurred in Queensland between 2010 and 2014. Additionally, an exploratory factor analysis was performed to investigate whether differing “types” of vulnerability could be identified.

Results: Increased family vulnerability was associated with four major known risk factors for sudden infant death: smoking, surface sharing, not-breastfeeding and use of excess bedding. However, families with lower levels of social vulnerability were more likely to display two major risk factors: prone infant sleep position and not room-sharing. There was a significant positive relationship between family vulnerability and the cumulative total of risk factors. Exploratory factor analysis identified three distinct vulnerability types (chaotic lifestyle, socioeconomic and psychosocial); the first two were associated with presence of major SUDI risk factors. Indigenous infants had significantly higher family vulnerability scores than non-Indigenous families.

Conclusion: A multidimensional measure that captures adversity across a range of indicators highlights the need for proportionate universalism to reduce the stalled rates of sudden infant death. In addition to information campaigns continuing to promote the importance of the back-sleeping position and close infant-caregiver proximity, socially vulnerable families should be a priority population for individually tailored or community based multi-model approaches.

How reliable is parental/carer assessment of infant health status?

Problems often arise in cases of lethal inflicted injury in infants and children in determining the chronology of events. However, on occasion it may be assumed that a parent's statement that the child appeared normal at a particular time is correct. It is then inferred that the lethal injury occurred after this time. In a study of infants from Queensland, Australia a significant number of cases occurred where a parent/carer did not actually recognise that an infant was deceased or in extremis despite handling of the infants, some of whom had established rigor mortis. Assessment of their infant's health status was quite flawed, presumably due to inattention, fatigue, or confirmatory bias (seeing what is expected). This could also apply to infants with head injuries who may manifest quite non-specific signs such as lethargy, somnolence or alteration in conscious state, manifestations that could easily be confused with normal drowsiness or sleep. Thus, the evaluation of parent/carer statements must be tempered by the knowledge that their opinions may not always (for completely understandable reasons) be reliable, and should not be uncritically accepted as a basis for deciding the time course for a lethal process.