Infant asphyxia, soft mattresses, and the "trough" effect

Parental obesity and the risk of sudden unexpected infant death

AIM

To clarify the possible role of accidental asphyxiation/suffocation for infants in shared sleeping situations.

METHODS

As it has recently been shown that there is an association between maternal obesity and sudden unexpected infant death (SUID) an index was calculated by dividing parental body mass index (BMI) by the shared sleeping surface area.

RESULTS

A much higher index was derived for an obese individual on a narrow sleeping area such as a sofa (50) compared to a thin adult on a queen-sized mattress (5).

CONCLUSION

The index may be a way of semi-quantitating high, and low, risk shared sleeping situations.

Infant death resulting from sharing a cot with a 10-year-old boy

An infant may die from unintentional suffocation if their exhausted, or inebriated or sedated mothers fall asleep while breast feeding or just sharing a bed and roll over on to them. The mother wakes up to find the baby dead in the morning. Diagnosis is complex due to minuscule autopsy findings and denial by parents about overlaying although it was accidental. Unusually, in this case, the baby was "over layed" by a young male child from the same family. The female baby was found listless next morning by her mother and died after three months of treatment. Death circumstances, non-sudden outcome, and unusual circumstances of overlaying the baby.

New Frameworks for Understanding Sudden Unexpected Deaths in Infancy (SUDI) in Socially Vulnerable Families

THEORETICAL PRINCIPLES

Sociological frameworks may enhance understanding of the complex and multidimensional nature of disadvantage, which is prevalent among families who experience Sudden Unexpected Death in Infancy (SUDI).

PHENOMENA ADDRESSED

SUDI is the largest category of postneonatal death and largely associated with the social determinants of health. The highly successful 'Back to Sleep' campaign has resulted in a more than 85% decrease in SUDI. However, social inequalities have accompanied this decrease, and the burden of SUDI now lies with the most disadvantaged and socially vulnerable families. A considerable body of research on the phenomena of SUDI and disadvantage has been published over the last decade, demonstrating the widening social gradient in SUDI, and the importance in recognising structural factors and the multifactorial nature of disadvantage. Gaps in understanding of risk factors and scepticism about the received wisdom of health professionals have emerged as central themes in understanding why socially vulnerable families may adopt unsafe infant care practices. The direct impact of social disadvantage on infant care has also been recognised.

RESEARCH LINKAGES

The translation of epidemiological findings regarding SUDI risk into public health recommendations for health professionals and families alike has to date focused on eliminating individual level risk behaviours. Unfortunately, such a model largely ignores the broader social, cultural, and structural contexts in which such behaviours occur. Translating the new knowledge offered by sociological frameworks and the principles of behavioural economics into evidence based interventions may assist in the reduction of SUDI mortality in our most socially vulnerable families.

An Approach to the Classification of Apparent Asphyxial Infant Deaths

Recent evidence indicates that with thorough, high quality death investigations and autopsies, forensic pathologists have recognized that many unexpected infant deaths are, in fact, asphyxial in nature. With this recognition has come a commensurate decrease in, and in some cases, abolition of, the label "sudden infant death syndrome" (SIDS). Current controversies often pertain to how and why some infant deaths are determined to be asphyxial in nature and whether or not apparent asphyxial circumstances are risk factors for SIDS, or rather, harbingers of asphyxial deaths. In an effort to sidestep these controversies, some forensic pathologists elected to instead use the noncommittal label "sudden unexpected infant death" (SUID), leading to the unfortunate consequence of SUID - like SIDS - gaining notoriety as an actual disease that could be diagnosed, studied, and ultimately cured. Although it is not possible to provide death certification guidance for every conceivable type of unexpected infant death, we recognize and propose a simple classification system for overarching themes that cover the vast majority of cases where infants die suddenly and unexpectedly.

Differences in African-American Maternal Self-Efficacy Regarding Practices Impacting Risk for Sudden Infant Death

Sudden Infant Death Syndrome (SIDS) and other sleep-related deaths, including accidental suffocation, account for ~4000 US deaths annually. Parents may have higher self-efficacy with regards to preventing accidental suffocation than SIDS. The objective of this study was to assess self-efficacy in African-American mothers with regards to safe sleep practices and risk for SIDS and accidental suffocation. As part of randomized clinical trial in African-American mothers of newborn infants, mothers completed a baseline survey about knowledge of and attitudes towards safe sleep recommendations, current intent, self-efficacy, and demographics. Tabular and adjusted, regression-based analyses of these cross-sectional data evaluated the impact of the message target (SIDS risk reduction vs. suffocation prevention) on perceived self-efficacy. 1194 mothers were interviewed. Mean infant age was 1.5 days. 90.8 % of mothers planned to place their infant supine, 96.7 % stated that their infant would sleep in the same room, 3.6 % planned to bedshare with the infant, and 72.9 % intended to have soft bedding in the crib. Mothers were more likely to believe that prone placement (70.9 vs. 50.5 %, p < 0.001), bedsharing (73.5 vs. 50.1 %, p < 0.001), and having soft bedding in the sleep area (78.3 vs. 59.5 %, p < 0.001) increased their infant's risk for suffocation than it did for SIDS. Mothers had higher self-efficacy, viz. increased confidence that their actions could keep their infant safe, with regards to suffocation than SIDS (88.0 vs. 79.4 %, p < 0.001). These differences remained significant when controlled for sociodemographics, grandmother in home, number of people in home, and breastfeeding intention. Maternal self-efficacy is higher with regards to prevention of accidental suffocation in African-Americans, regardless of sociodemographics. Healthcare professionals should discuss both SIDS risk reduction and prevention of accidental suffocation when advising African-American parents about safe sleep practices.

Infant gender, shared sleeping and sudden death

AIM

To determine whether there is a gender imbalance in infant deaths in shared sleeping compared to solitary sleeping situations.

METHODS

Examination of autopsy reports of 133 infants aged between 7 and 364 days autopsied over a 19-year period from January 1991 to December 2009 was undertaken where death had either been attributed to SIDS, or had been classified as undetermined or unascertained. Cases were divided into two groups of solitary sleepers and shared sleepers, and the ratio of male to female cases was compared.

RESULTS

Ninety-five solitary sleepers were aged from 1 to 11 months (average 4.1 months) and consisted of 63 males (age range 1 to 11 months) and 32 females (age range 1 to 10 months). The 38 shared sleepers were aged from 1 week to 12 months (average 2.6 months) and consisted of 17 males (age range 2 weeks to 5 months) and 21 females (age range 1 week to 10 months). The male to female ratio in the solitary sleepers was approximately 2:1 and in the shared sleepers was 0.8:1, a statistically significant difference (p = 0.02).

CONCLUSION

The lack of a male predominance typical of SIDS cases in infants who were sleeping with others, compared to those who were sleeping alone, suggests that these situations may be different. It is possible, therefore, that different lethal mechanisms may be involved in some shared sleeping situations.

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.