Sudden Unexpected Death In Infancy Cases Research Articles

Sudden unexpected infant death characteristics in the French region of West Provence-Alpes-Côte d’Azur

ABSTRACTBackground: Although the incidence of sudden unexpected infant death (SUID) has decreased since the ‘Back to Sleep’ campaign in English-speaking countries and other preventive campaigns, the circumstances of such deaths remain unclear.Aim: To analyse infant deaths recorded at the referral centre for sudden infant death of the West Provence-Alpes-Côte d’Azur region of France (West PACA) and the forensic medicine department of Marseille University Hospital.Methods: Information on all SUID cases from 2000 to 2017 was extracted from the referral centre for sudden infant deaths in West PACA and the forensic medicine department of Marseille.Results: The study included 130 infants over the 17 years with a very similar distribution. There was a marked male preponderance, with 61.6% of boys whatever the age at death (sex ratio 1.6). Half of the deaths occurred in the first 6 months of life and the majority (61%) of infants died during autumn and winter. Nearly one-third (33.2%) had presented with minor infections and 21% had been seen by a doctor or had been admitted to hospital. Most deaths (86.4%) occurred during sleep (night or day). Nearly half of the infants (47.7%) were discovered in a prone position. A large majority of parents (90.7%) agreed to a post-mortem examination. Only 6.2% of deaths led to legal proceedings. Nearly 16.9% remained unexplained after compiling all the data included in the protocol and 9.2% remained unexplained because of incomplete investigation, including refusal of post-mortem examination. Abuse was involved in 2.3% of cases.Conclusions: Asymptomatic infectious conditions were associated with a high proportion of SUID cases. Non-supine sleep positions were still practised. There is a need to increase SUID prevention campaigns.Abbreviations: HAS, Haute Autorité de Santé: French National Health Authority; NICHD, National Institute of Child Health and Human Development; PACA, Provence-Alpes-Côte d’Azur region of France; SUID, sudden unexpected infant death; SIDS, sudden infant death syndrome; CépiDc, Centre d’Epidémiologie sur les Causes Médicales de Décès/Center for Epidemiology on the Medical Causes of Death

Safeguarding Children and Young People is Everyone's Responsibility

Safeguarding Children and Young People is Everyone's Responsibility

Qualitative analysis of serious case reviews into unexpected infant deaths

ObjectiveTo develop a detailed understanding of the circumstances of sudden unexpected death in infancy (SUDI) cases subject to serious case review (SCR).DesignThis was a thematic analysis of SCRs relating to...

Neuronal apoptosis in the brainstem medulla of sudden unexpected death in infancy (SUDI), and the importance of standardized SUDI classification.

The purpose of this study was to examine the neuronal expression of apoptotic markers in the rostral medulla of a newly characterized dataset of sudden unexpected death in infancy (SUDI), and to determine the impact of diagnostic groupings on these findings and whether they pertain to the intrinsic apoptotic pathway. Immunohistochemical staining was quantified to determine the percentage of neurons positive for active caspase-9 (specific to the intrinsic apoptotic pathway), active caspase-3 (common to the intrinsic and extrinsic apoptotic pathways) and Terminal deoxynucleotidyl transferase mediated dUTP nick-end labelling (TUNEL) (labels DNA fragmentation) in nine nuclei of the rostral medulla. Expression was compared between groups of SUDI infants where the cause of death was initially classified by a forensic pathologist or subsequently after reclassification by an expert panel using the San Diego Criteria. 68 SUDI infants were studied and originally classified as explained SUDI (n = 12), Sudden Infant Death Syndrome (SIDS) (n = 27) and undetermined (n = 29). Reclassification resulted in a decrease in the number of explained SUDI cases to 7 and a decrease in the number of undetermined cases to 4, with a corresponding increase in the number of SIDS cases to 57 (8 SIDS I; 49 SIDS II). The expression of apoptotic markers was similar in explained SUDI and SIDS I infants. However, TUNEL expression was greater in the cuneate (p < 0.001), vestibular (p = 0.01) and hypoglossal (p < 0.001) nuclei and active caspase-3 expression was lower in the arcuate nucleus (p = 0.037) in SIDS II compared to explained Sudden Unexpected Death in Infancy (eSUDI) infants. Compared to SIDS I infants, SIDS II infants had greater TUNEL expression in the dorsal motor nucleus of the vagus (p < 0.01) and greater active caspase-9 expression in the medial and spinal vestibular nuclei (p = <0.01). Changes in apoptotic expression predominated in SIDS II infants. We postulate that these are due to a combination of contributing risk factors including the presence of an upper respiratory tract infection and bed-sharing/co-sleeping. The absence of changes in active caspase-9 expression compared to eSUDI indicates that the intrinsic apoptotic pathway is not upregulated in SIDS.

Prematurity and Sudden Unexpected Infant Deaths in the United States.

Prematurity, a strong risk factor for sudden unexpected infant death (SUID), was addressed in recommendations by the American Academy of Pediatrics in 2011 for safe sleep education in NICUs. We documented associations between gestational age (GA) and SUID subsequent to these guidelines. Using the 2012-2013 US linked infant birth and death certificate period files, we documented rates per live births of sudden infant death syndrome, ill-defined and unspecified causes, accidental suffocation and strangulation in bed, and overall SUID by GA in postneonatal, out-of-hospital, and autopsied cases; compared survivors and cases; and estimated logistic regression models of associations between GA and SUID. SUID cases were more likely than survivors to be <37 weeks' GA (22.61% vs 10.79%; P < .0001). SUID rates were 2.68, 1.94, 1.46, 1.16, 0.73, and 0.51 per 1000 live births for 24 to 27, 28 to 31, 32 to 33, 34 to 36, 37 to 38, and 39 to 42 weeks' GA, respectively. Logistic regression models additionally indicated declines in the risk for SUID as GA increased. Prenatal smoking, inadequate prenatal care, and demographics associated with poverty were strongly associated with SUID. Despite the 2011 American Academy of Pediatrics recommendations for increased safe sleep education in the NICUs, SUID rates were inversely associated with GA in 2012 to 2013, suggesting that risk of SUID associated with prematurity has multiple etiologies requiring continued investigation, including biological vulnerabilities and the efficacy of NICU education programs, and that strategies to reduce SUID should be multifaceted.

The Sudden Death in the Young Case Registry: Collaborating to Understand and Reduce Mortality.

Knowledge gaps persist about the incidence of and risk factors for sudden death in the young (SDY). The SDY Case Registry is a collaborative effort between the National Institutes of Health, the Centers for Disease Control and Prevention, and the Michigan Public Health Institute. Its goals are to: (1) describe the incidence of SDY in the United States by using population-based surveillance; (2) compile data from SDY cases to create a resource of information and DNA samples for research; (3) encourage standardized approaches to investigation, autopsy, and categorization of SDY cases; (4) develop partnerships between local, state, and federal stakeholders toward a common goal of understanding and preventing SDY; and (5) support families who have lost loved ones to SDY by providing resources on bereavement and medical evaluation of surviving family members. Built on existing Child Death Review programs and as an expansion of the Sudden Unexpected Infant Death Case Registry, the SDY Case Registry achieves its goals by identifying SDY cases, providing guidance to medical examiners/coroners in conducting comprehensive autopsies, evaluating cases through child death review and an advanced review by clinical specialists, and classifying cases according to a standardized algorithm. The SDY Case Registry also includes a process to obtain informed consent from next-of-kin to save DNA for research, banking, and, in some cases, diagnostic genetic testing. The SDY Case Registry will provide valuable incidence data and will enhance understanding of the characteristics of SDY cases to inform the development of targeted prevention efforts.

A "Wear and Tear" Hypothesis to Explain Sudden Infant Death Syndrome.

Sudden infant death syndrome (SIDS) is the leading cause of death among USA infants under 1 year of age accounting for ~2,700 deaths per year. Although formally SIDS dates back at least 2,000 years and was even mentioned in the Hebrew Bible (Kings 3:19), its etiology remains unexplained prompting the CDC to initiate a sudden unexpected infant death case registry in 2010. Due to their total dependence, the ability of the infant to allostatically regulate stressors and stress responses shaped by genetic and environmental factors is severely constrained. We propose that SIDS is the result of cumulative painful, stressful, or traumatic exposures that begin in utero and tax neonatal regulatory systems incompatible with allostasis. We also identify several putative biochemical mechanisms involved in SIDS. We argue that the important characteristics of SIDS, namely male predominance (60:40), the significantly different SIDS rate among USA Hispanics (80% lower) compared to whites, 50% of cases occurring between 7.6 and 17.6 weeks after birth with only 10% after 24.7 weeks, and seasonal variation with most cases occurring during winter, are all associated with common environmental stressors, such as neonatal circumcision and seasonal illnesses. We predict that neonatal circumcision is associated with hypersensitivity to pain and decreased heart rate variability, which increase the risk for SIDS. We also predict that neonatal male circumcision will account for the SIDS gender bias and that groups that practice high male circumcision rates, such as USA whites, will have higher SIDS rates compared to groups with lower circumcision rates. SIDS rates will also be higher in USA states where Medicaid covers circumcision and lower among people that do not practice neonatal circumcision and/or cannot afford to pay for circumcision. We last predict that winter-born premature infants who are circumcised will be at higher risk of SIDS compared to infants who experienced fewer nociceptive exposures. All these predictions are testable experimentally using animal models or cohort studies in humans. Our hypothesis provides new insights into novel risk factors for SIDS that can reduce its risk by modifying current infant care practices to reduce nociceptive exposures.

Unintentional asphyxia, SIDS, and medically explained deaths: a descriptive study of outcomes of child death review (CDR) investigations following sudden unexpected death in infancy.

A comprehensive child death review (CDR) program was introduced in England and Wales in 2008, but as yet data have only been analyzed at a local level, limiting the learning from deaths. The aim of this study is to describe the profile of causes and risk factors for sudden unexpected death in infancy (SUDI) as determined by the new CDR program. This was a descriptive outcome study using data from child death overview panel Form C for SUDI cases dying during 2010-2012 in the West Midlands region of England. The main outcome measures were: cause of death, risk factors and potential preventability of death, and determination of deaths probably due to unintentional asphyxia. Data were obtained for 65/70 (93%) SUDI cases. 20/65 (31%) deaths were initially categorized as due to medical causes; 21/65 (32%) as SIDS; and 24/65 (37%) as undetermined. Reanalysis suggested that 2/21 SIDS and 7/24 undetermined deaths were probably due to unintentional asphyxia, with 6 of these involving co-sleeping and excessive parental alcohol consumption. Deaths classified as "undetermined" had significantly higher total family and environmental risk factor scores (mean 2.6, 95% CI 2.0-3.3) compared to those classified as SIDS (mean 1.6, 95% CI 1.2-1.9), or medical causes for death (mean 1.1, 95% CI 0.8-1.3). 9/20 (47%) of medical deaths, 19/21 (90%) SIDS, and 23/24 (96%) undetermined deaths were considered to be potentially preventable. There were inadequacies in medical provision identified in 5/20 (25%) of medically explained deaths. The CDR program results in detailed information about risk factors for SUDI cases but failed to recognize deaths probably due to unintentional asphyxia. The misclassification of probable unintentional asphyxial deaths and SIDS as "undetermined deaths" is likely to limit learning from these deaths and inhibit prevention strategies. Many SUDI occurred in families with mental illness, substance misuse and chaotic lifestyles and most in unsafe sleep environments. This knowledge could be used to better target safe sleep advice for vulnerable families and prevent SUDI in the future.

Death Scene Investigation and Autopsy Practices in Sudden Unexpected Infant Deaths

To describe and compare sudden unexpected infant death (SUID) investigations among states participating in the SUID Case Registry from 2010 through2012. We analyzed observational data from 770 SUID cases identified and entered into the National Child Death Review Case Reporting System. We examined data on autopsy and death scene investigation (DSI) components, including key information about the infant sleep environment. We calculated the percentage of components that were complete, incomplete, and missing/unknown. Most cases (98%) had a DSI. The DSI components most frequently reported as done were the narrative description of the circumstances (90%; range, 85%-99%), and witness interviews (88%, range, 85%-98%). Critical information about 10 infant sleep environment components was available for 85% of cases for all states combined. All 770 cases had an autopsy performed. The autopsy components most frequently reported as done were histology, microbiology, and other pathology (98%; range, 94%-100%) and toxicology (97%; range, 94%-100%). This study serves as a baseline to understand the scope of infant death investigations in selected states. Standardized and comprehensive DSI and autopsy practices across jurisdictions and states may increase knowledge about SUID etiology and also lead to an improved understanding of the cause-specific SUID risk and protective factors. Additionally, these results demonstrate practices in the field showing what is feasible in these select states. We encourage pediatricians, forensic pathologists, and other medicolegal experts to use these findings to inform system changes and improvements in DSI and autopsy practices and SUID prevention efforts.

Postmortem diagnosis of cytomegalovirus and accompanying other infection agents by real-time PCR in cases of sudden unexpected death in infancy (SUDI)

As an opportunistic pathogen with high mortality rates, Cytomegalovirus (CMV) may lead to fatal disseminated CMV infection of the premature and newborn; thus necessitating the demonstration of CMV-DNA with clinical history and/or histopathological findings of CMV infection and defining other bacterial and viral infection agents with real-time polymerase chain reaction (RT-PCR) in udden unexpected death in infancy (SUDI) cases as we aimed in this study.314 (144 female, 170 male) SUDI cases were prospectively investigated from January 2013 to January 2015 in Istanbul Forensic Medicine Institution. The study includes 87 tissue samples of 39 cases for post-mortem histopathological examination of interstitial pneumonia, myocarditis, meningitis, encephalitis, hepatitis, colitis or tubulointerstitial nephritis and/or accompanying chronic sialadenitis.CMV-DNA was found positive in 35 (40.2%) salivary gland, 19 (21.8%) lung, 1 (1.1%) tonsil, and 1 (1.1%) brain tissues. CMV sialadenitis and/or CMV pneumonia associated with other viral and/or bacterial agents were detected in 23 (60%) of 39 infant cases.The demonstration of CMV-DNA would significantly clarify the cause of death and collection of epidemiological data in SUDI cases with clinical history and histopathological findings of CMV infection accompanying chronic CMV sialadenitis. Furthermore, CMV suppresses the immune system, and may predispose to other bacterial and/or viral infections in these cases. Post-mortem molecular investigations are useful in explaining cause of death in SUDI with a suspicion of infection in forensic autopsies.

Genetic investigations of sudden unexpected deaths in infancy using next-generation sequencing of 100 genes associated with cardiac diseases.

Sudden infant death syndrome (SIDS) is the most frequent manner of post-perinatal death among infants. One of the suggested causes of the syndrome is inherited cardiac diseases, mainly channelopathies, that can trigger arrhythmias and sudden death. The purpose of this study was to investigate cases of sudden unexpected death in infancy (SUDI) for potential causative variants in 100 cardiac-associated genes. We investigated 47 SUDI cases of which 38 had previously been screened for variants in RYR2, KCNQ1, KCNH2 and SCN5A. Using the Haloplex Target Enrichment System (Agilent) and next-generation sequencing (NGS), the coding regions of 100 genes associated with inherited channelopathies and cardiomyopathies were captured and sequenced on the Illumina MiSeq platform. Sixteen (34%) of the SUDI cases had variants with likely functional effects, based on conservation, computational prediction and allele frequency, in one or more of the genes screened. The possible effects of the variants were not verified with family or functional studies. Eight (17%) of the SUDI cases had variants in genes affecting ion channel functions. The remaining eight cases had variants in genes associated with cardiomyopathies. In total, one third of the SUDI victims in a forensic setting had variants with likely functional effect that presumably contributed to the cause of death. The results support the assumption that channelopathies are important causes of SUDI. Thus, analysis of genes associated with cardiac diseases in SUDI victims is important in the forensic setting and a valuable supplement to the clinical investigation in all cases of sudden death.

International comparison of sudden unexpected death in infancy rates using a newly proposed set of cause-of-death codes

BackgroundComparing rates of sudden unexpected death in infancy (SUDI) in different countries and over time is difficult, as these deaths are certified differently in different countries, and, even within the...

G421 The current causes and risk factors for sudi

Aims Since 2008, in England, all unexpected child deaths undergo a multi-agency investigation with the aim of determining the complete cause of death; followed by review by local Child Death Overview Panels (CDOP). These new processes have yet to be evaluated. This study aims to determine the effectiveness of the multi-agency investigation and CDOP processes in ascertaining causes of death and risk factors following Sudden Unexpected Death in Infancy (SUDI) and to describe the profile of causes and risk factors. Methods We obtained the dates of birth and death of all SUDI cases from one English region, dying between 1 September 2010 and 31 August 2012. We contacted all 10 CDOP for copies of individual case reviews completed using the standard CDOP Form C. We extracted the age, cause of death and presence of modifiable factors for each case from the Form C and created a total family and environmental risk factor score by totalling the risk factors. Results Data were obtained for 65/70 (93%) SUDI cases. 20/65 (31%) deaths were due to medical causes; 21/65 (32%) due to SIDS and 24/65 (37%) classified as unascertained deaths. Reanalysis of case data suggested that 9 deaths were probably due to accidental asphyxia, with 6 of these involving parents co-sleeping with their infant after consuming excessive alcohol. Unascertained deaths had significantly higher total family and environmental risk factor scores (mean 2.6, 95% CI 2.0–3.3) compared to SIDS (mean 1.6, 95% CI 1.2–1.9), or medical causes for death (mean 1.1, 95% CI 0.8–1.3). 9/20 (47%) of medical deaths. 19/21 (90%) SIDS and 23/24 (96%) unascertained deaths were considered to be preventable. There were inadequacies in medical provision identified in 5/20 (25%) of medically explained deaths. Conclusions The new multi-agency child death processes are effective at determining cause of death and risk factors for SUDI but potential asphyxia deaths may not be recognised. Most deaths labelled as unascertained fulfilled diagnostic criteria for SIDS. Many SUDI occurred in families with mental illness, drug or alcohol misuse and chaotic lifestyles and most in unsafe sleep-environments.

Classification system for the Sudden Unexpected Infant Death Case Registry and its application.

Sudden unexpected infant deaths (SUID) accounted for 1 in 3 postneonatal deaths in 2010. Sudden infant death syndrome and accidental sleep-related suffocation are among the most frequently reported types of SUID. The causes of these SUID usually are not obvious before a medico-legal investigation and may remain unexplained even after investigation. Lack of consistent investigation practices and an autopsy marker make it difficult to distinguish sudden infant death syndrome from other SUID. Standardized categories might assist in differentiating SUID subtypes and allow for more accurate monitoring of the magnitude of SUID, as well as an enhanced ability to characterize the highest risk groups. To capture information about the extent to which cases are thoroughly investigated and how factors like unsafe sleep may contribute to deaths, CDC created a multistate SUID Case Registry in 2009. As part of the registry, the Centers for Disease Control and Prevention developed a classification system that recognizes the uncertainty about how suffocation or asphyxiation may contribute to death and that accounts for unknown and incomplete information about the death scene and autopsy. This report describes the classification system, including its definitions and decision-making algorithm, and applies the system to 436 US SUID cases that occurred in 2011 and were reported to the registry. These categories, although not replacing official cause-of-death determinations, allow local and state programs to track SUID subtypes, creating a valuable tool to identify gaps in investigation and inform SUID reduction strategies.

Sudden unexpected death in infancy (SUDI) in the early neonatal period: the role of bed-sharing

The incidence of sudden infant death syndrome (SIDS) has declined substantially, but the proportion of sudden unexpected death in infancy (SUDI) in neonates, <7days old, has increased among all SUDI cases in the first year of life. The aim of this study was to analyze circumstances and common features of SUDI cases during the first 7days of life. Data have been gathered retrospectively from Departments of Legal Medicine in Germany and Austria by using a standardized questionnaire. 19 out of 46 children died within 24h after birth. A possible reason for this could be a lack of awareness of the needs of the newborn on the part of an exhausted mother. Fifty-two percent of the incidents occurred while the mother and her newborn were still hospitalized in a birth clinic. Forty-eight percent of the infants had been sleeping in the parents' bed with mother and/or father. In 11% of the cases, there was a sofa-sharing situation. Bed-sharing seems to increase the risk for SIDS in the newborn period as well as the risk for accidental suffocation/asphyxia of the baby. Therefore, mothers should not be instructed to bed-share. Particularly during the first 24h after birth, it may be advisable to check mothers and infants regularly.

Carnitine palmitoyltransferase 2 gene polymorphism is a genetic risk factor for sudden unexpected death in infancy

RationaleCarnitine palmitoyltransferase (CPT) II is one of a pivotal enzyme in mitochondrial fatty acid oxidation, which is essential for energy production during simultaneous glucose sparing and a requirement for major energy supply, such as prolonged fasting or exercise. When infants require more energy than provided by the glycolytic system, they rely on the mitochondrial fatty acid oxidation pathway. Mutations of the CPT2 gene have been reported to cause sudden unexpected death in infancy (SUDI). A thermolabile phenotype of a CPT2 polymorphism (F352C) has been recently reported to reduce CPT II enzyme activity. The F352C variant results in energy crisis at high temperature and is suspected as a risk factor for acute encephalopathy. However, a relationship between CPT2 gene polymorphism and SUDI has not been described. MethodsSingle nucleotide polymorphisms of the CPT2 gene were investigated among 54 SUDI cases and 200 healthy volunteers. ResultsThe frequency of the C allele was significantly higher in the SUDI group than in the control group [25.0% vs 16.0%, odds ratio (OR)=1.75, 95% confidence interval (CI)=1.05–2.92, p=0.030). The frequency of the F352C homozygote was significantly higher in the SUDI group than in control group (11.1% vs 3.5%, OR=3.45, 95% CI=1.11–10.73, p=0.036). ConclusionThe F352C CPT2 variant might be a genetic risk factor for SUDI.

Sudden Unexpected Infant Death: A Compassionate Forensic Approach to Care

Sudden unexpected infant death (SUID), and more specifically sudden infant death syndrome (SIDS), is the leading cause of death of infants outside of the neonatal period in the United States. In approximately 10%-20% of cases of SUID a specific cause of death is identified. In the majority of cases, however, a thorough investigation including autopsy, examination of the death scene and a review of the clinical history fails to identify a specific cause of death and a diagnosis of SIDS is made. The possible causes of SIDS are numerous, and to date, there is no adequate unifying pathological or genetic explanation. All families of young infants should be counseled on the known modifiable risk factors of SIDS and SUIDS including safe sleep environment, smoking, and pacifier use. Responding to a SUID in the emergency department presents challenges from an emotional, cultural, procedural and legal perspective. A team-based approach to provide family-centered care that is personal, individualized, compassionate and culturally sensitive is recommended.

Radiological findings at a South African forensic pathology laboratory in cases of sudden unexpected death in infants

Objectives&#x0D; The work serves as a preliminary evaluation of the utility of the full-body radiography in examining cases of SUDI.&#x0D; &#x0D; Setting&#x0D; This paper reviews findings from full-body digital radiography in cases of sudden unexpected death in infants (SUDI) in 2008 at the Salt River Forensic Pathology Laboratory in Cape Town. &#x0D; &#x0D; Subjects&#x0D; Cases of SUDI referred to the mortuary and undergoing full-body digital radiography were reviewed (192 cases). &#x0D; &#x0D; Design&#x0D; Imaging reports were cross-referenced with death registry data. Manner of death, cause of death, whether an autopsy had taken place, and radiological findings, were recorded and analysed. &#x0D; &#x0D; Results&#x0D; The absence of bony fractures was recorded as an imaging finding in 40% of cases. The most common type of imaging pathology was lung disease. In cases where autopsies were performed and pathology was found on imaging, the findings of the two methods of examination were consistent.&#x0D; &#x0D; Conclusions&#x0D; Imaging may have served to assist CoD determination based on case history, and therefore full-body radiography may improve the workflow in busy forensic pathology laboratories.&#x0D; More detailed and consistent recording of imaging findings is required before stronger conclusions may be drawn regarding the utility of full body digital imaging of paediatric cases in forensic pathology laboratories.

Role of routine neuropathological examination for determining cause of death in sudden unexpected deaths in infancy (SUDI)

BackgroundCurrent guidelines for the investigation of sudden unexpected death in infancy (SUDI) include full neuropathological examination with recommendations for brain fixation for 1–2 weeks. Little evidence is available regarding the...

Application of a classification system focusing on potential asphyxia for cases of sudden unexpected infant death

Current classification schemes for sudden unexpected infant death (SUID) may not be optimal for capturing scene events that potentially predispose to asphyxia. (1) To compare causes of death in a group of SUID cases assigned by multiple reviewers using our recently published classification scheme for SUID that is based on asphyxial risk at the death scene, and (2) To compare these newly assigned causes of death to that originally assigned by the medical examiners of record who performed the autopsies. Five reviewers independently assigned causes of death for 117 cases of SUID, including 83 originally diagnosed as sudden infant death syndrome (SIDS), accessioned into the San Diego SIDS/SUDC Research Project from the San Diego County Medical Examiner's Office. The diagnostic categories are: A: SIDS; B: Unexplained-Potentially Asphyxia; C: Unexplained-Other Potential Causes of Death; D: Unclassified-Other; E: Unclassified; and F: Known Cause of Death. The reviewers collectively opined that conditions at the death scene contributed to or caused death in 32-50% of all of the 117 cases as well as in 40-59% of the 83 originally diagnosed SIDS cases. Another cause of death was considered plausible in 2-12% of the SIDS cases. Application of this new classification system resulted in 55-69% decrease in SIDS diagnoses. Asphyxia as a potential contributor to, or as the specific cause of death, appears to exist in a large percentage of cases designated as SIDS using other classification schemes. When certifiers use a classification system that focuses upon potential asphyxia in determining the cause of death the incidence of SIDS dramatically declines.