Risk of Sudden Infant Death Syndrome Among Siblings of Children Who Died of Sudden Infant Death Syndrome in Denmark

IMPORTANCE

Sudden infant death syndrome (SIDS) remains a leading cause of death during the first year of life. The etiology of SIDS is complex and remains largely unknown.

OBJECTIVE

To evaluate whether siblings of children who died of SIDS have a higher risk of SIDS compared with the general pediatric population.

DESIGN, SETTING, AND PARTICIPANTS

This register-based cohort study used Danish nationwide registers. Participants were all infants (<1 year) in Denmark between January 1, 1978, and December 31, 2016, including siblings of children who died of SIDS. Siblings were followed up from the index cases' date of SIDS, date of birth, or immigration, whichever came first, and until age 1 year, emigration, developing SIDS, death, or study end. The median (IQR) follow-up was 1 (1-1) year. Data analysis was conducted from January 2017 to October 2022.

MAIN OUTCOMES AND MEASURES

Standardized incidence ratios (SIRs) of SIDS were calculated with Poisson regression models relative to the general population.

RESULTS

In a population of 2 666 834 consecutive births (1 395 199 [52%] male), 1540 infants died of SIDS (median [IQR] age at SIDS, 3 [2-4] months) during a 39-year study period. A total of 2384 younger siblings (cases) to index cases (first sibling with SIDS) were identified. A higher rate of SIDS was observed among siblings compared with the general population, with SIRs of 4.27 (95% CI, 2.13-8.53) after adjustment for sex, age, and calendar year and of 3.50 (95% CI, 1.75-7.01) after further adjustment for mother's age (<29 years vs ≥29 years) and education (high school vs after high school).

CONCLUSIONS AND RELEVANCE

In this nationwide study, having a sibling who died of SIDS was associated with a 4-fold higher risk of SIDS compared with the general population. Shared genetic and/or environmental factors may contribute to the observed clustering of SIDS. The family history of SIDS should be considered when assessing SIDS risk in clinical settings. A multidisciplinary genetic evaluation of families with SIDS could provide additional evidence.

Risk Factors for Suffocation and Unexplained Causes of Infant Deaths

BACKGROUND

Observational studies have improved our understanding of the risk factors for sudden infant death syndrome, but separate examination of risk for sleep-related suffocation and unexplained infant deaths has been limited. We examined the association between unsafe infant sleep practices and sudden infant deaths (sleep-related suffocation and unexplained causes including sudden infant death syndrome).

METHODS

We conducted a population-based case-control study using 2016 to 2017 Centers for Disease Control and Prevention data. Controls were liveborn infants from the Pregnancy Risk Assessment Monitoring System; cases were from the Sudden Unexpected Infant Death Case Registry. We calculated risk factor prevalence among cases and controls and crude and adjusted odds ratios.

RESULTS

We included 112 sleep-related suffocation cases with 448 age-matched controls and 300 unexplained infant death cases with 1200 age-matched controls. Adjusted odds for sleep-related suffocation ranged from 18.7 (95% confidence interval [CI]: 6.8-51.3) among infants not sharing a room with their mother or caregiver to 1.9 (95% CI: 0.9-4.1) among infants with nonsupine sleep positioning. Adjusted odds for unexplained death ranged from 7.6 (95% CI: 4.7-12.2) among infants not sharing a room with their mother or caregiver to 1.6 (95% CI: 1.1-2.4) among nonsupine positioned infants.

COCLUSIONS

We confirmed previously identified risk factors for unexplained infant death and independently estimated risk factors for sleep-related suffocation. Significance of associations for suffocation followed similar patterns but was of larger magnitude. This information can be used to improve messaging about safe infant sleep.

Impact of Prenatal Nicotine Exposure on Placental Function and Respiratory Neural Network Development

Smoking during pregnancy is associated with multiple undesirable outcomes in infants, such as low birth weight, increased neonatal morbidity and mortality, and catastrophic conditions like sudden infant death syndrome (SIDS). Nicotine, the most addictive and teratogenic substance in tobacco smoke, reaches and crosses the placenta and can be accumulated in the amniotic fluid and distributed by fetal circulation, altering the cholinergic transmission by acting on the nicotinic acetylcholine receptors (nAChRs) expressed from very early gestational stages in the placenta and fetal tissue. Because nAChRs influence the establishment of feto-maternal circulation and the emergence of neuronal networks, prenatal nicotine exposure can lead to multiple alterations in newborns. In this mini-review, we discuss the undeniable effects of nicotine in the placenta and the respiratory neural network as examples of how prenatal nicotine and smoking exposition can affect brain development because dysfunction in this network is involved in SIDS etiology.

Characteristics and Geographic Variation in Sudden Unexpected Infant Deaths in the District of Columbia

ABSTRACT

Sleep-related infant death is a major cause of infant mortality in the United States. In the District of Columbia, infant mortality varies widely among regions (2 to 14 per 1000 live births). The study objectives were to analyze the patient characteristics and related variables to sudden unexpected infant deaths at 2 pediatric emergency department (ED) sites and the geographic patterns of infant deaths and their relationship to social vulnerability. This retrospective cohort study examined infants under 1 year of age presenting with cardiac arrest at 2 ED sites from 2010 to 2020. Analysis showed 81 deaths with a median population age of 75 days (SD, 46 days). The most frequent demographics of deceased patients were African American Black (89%) with Medicaid insurance (63%), born at term gestation (66%), and without comorbidity (60%). The cause of death was most frequently undetermined (32%) and asphyxia (31%). Most cases involved bed-sharing (63%), despite more than half of those cases having a known safe sleep surface available. Infant death location showed that most deaths occurred in areas with the highest social vulnerability index, including near a community ED location. Understanding the etiologies of this geographic variability may enhance sleep-related infant death prevention strategies.

Maternal, infant, and environmental risk factors for sudden unexpected infant deaths: results from a large, administrative cohort

OBJECTIVES

Many studies of sudden unexpected infant death (SUID) have focused on individual domains of risk factors (maternal, infant, and environmental), resulting in limited capture of this multifactorial outcome. The objective of this study was to examine the geographic distribution of SUID in San Diego County, and assess maternal, infant, and environmental risk factors from a large, administrative research platform.

STUDY DESIGN

Births in California between 2005 and 2017 were linked to hospital discharge summaries and death files. From this retrospective birth cohort, cases of SUID were identified from infant death files in San Diego County. We estimated adjusted hazard ratios (aHRs) for infant, maternal, and environmental factors and SUID in multivariable Cox regression analysis. Models were adjusted for maternal sociodemographic characteristics and prenatal nicotine exposure.

RESULTS

There were 211 (44/100,000 live births; absolute risk 0.04%) infants with a SUID among 484,905 live births. There was heterogeneity in geographic distribution of cases. Multiparity (0.05%; aHR 1.4, 95% confidence interval (CI) 1.1, 1.9), maternal depression (0.11%; aHR 1.8, 95% CI 1.0, 3.4), substance-related diagnoses (0.27%; aHR 2.3, 95% CI 1.3, 3.8), cannabis-related diagnosis (0.35%; aHR 2.7, 95% CI 1.5, 5.0), prenatal nicotine use (0.23%; aHR 2.5, 95% CI 1.5, 4.2), preexisting hypertension (0.11%; aHR 2.3, 95% CI 1.2, 4.3), preterm delivery (0.09%; aHR 2.1, 95% CI 1.5, 3.0), infant with a major malformation (0.09%; aHR 2.0, 95% CI 1.1, 3.6), respiratory distress syndrome (0.12%; aHR 2.6, 95% CI 1.5, 4.6), and select environmental factors were all associated with SUID.

CONCLUSIONS

Multiple risk factors were confirmed and expanded upon, and the geographic distribution for SUID in San Diego County was identified. Through this approach, prevention efforts can be targeted to geographies that would benefit the most.

Comparing asphyxia and unexplained causes of death: a retrospective cohort analysis of sleep-related infant death cases from a state child fatality review programme

OBJECTIVES

To examine the characteristics and circumstances of infants who died while sleeping or in a sleep environment and compare deaths classified as either unintentional asphyxia or an unexplained cause.

DESIGN

A retrospective cohort study.

SETTING

Data were extracted from the National Fatality Review Case Reporting System and Florida Vital Statistics databases.

PARTICIPANTS

Data on 778 sleep-related infant deaths occurring from 2014 to 2018 in Florida were analysed.

PRIMARY OUTCOME MEASURE

Cause of death classification as unintentional asphyxia or unexplained.

RESULTS

Overall, 36% (n=276) of sleep-related infant deaths in this study sample were classified as resulting from an unexplained cause compared with unintentional asphyxia. Most infants were reported to be in an adult bed (60%; n=464) and sharing a sleep surface with a person or animal (60%; n=468); less than half (44%; n=343) were reportedly placed to sleep on their back. After controlling for the influence of other independent variables, female sex (adjusted risk ratio: 1.36; 95% CI 1.06 to 1.74) and fully obstructed airway condition (adjusted risk ratio: 0.30; 95% CI 0.18 to 0.50) were associated with an unexplained cause of death.

CONCLUSIONS

The results of this analysis indicate that sleep environment hazards remain prevalent among infants who die suddenly and unexpectedly, regardless of the cause of death determination. While significant differences were observed for some factors, in many others the distributions of both demographic and incident characteristics were similar between unexplained deaths and those resulting from asphyxia. The results of this study support growing evidence that unsafe sleep environments contribute to all forms of sudden unexpected infant death, underscoring the need for standardising cause of death determination practices and promoting consistent, high-quality forensic investigations to accurately explain, monitor and prevent these deaths.

Development of a Risk Score to Predict Sudden Infant Death Syndrome

Sudden Infant Death Syndrome (SIDS) is the third leading cause of death among infants younger than one year of age. Effective SIDS prediction models have yet to be developed. Hence, we developed a risk score for SIDS, testing contemporary factors including infant exposure to passive smoke, circumcision, and sleep position along with known risk factors based on 291 SIDS and 242 healthy control infants. The data were retrieved from death certificates, parent interviews, and medical records collected between 1989−1992, prior to the Back to Sleep Campaign. Multivariable logistic regression models were performed to develop a risk score model. Our finalized risk score model included: (i) breastfeeding duration (OR = 13.85, p < 0.001); (ii) family history of SIDS (OR = 4.31, p < 0.001); (iii) low birth weight (OR = 2.74, p = 0.003); (iv) exposure to passive smoking (OR = 2.64, p < 0.001); (v) maternal anemia during pregnancy (OR = 2.07, p = 0.03); and (vi) maternal age <25 years (OR = 1.77, p = 0.01). The area under the curve for the overall model was 0.79, and the sensitivity and specificity were 79% and 63%, respectively. Once this risk score is further validated it could ultimately help physicians identify the high risk infants and counsel parents about modifiable risk factors that are most predictive of SIDS.

Safe Sleep Behaviors and Factors Associated With Infant Second Sleep Practices

OBJECTIVES

To examine the prevalence and safety of infant second-sleep practices.

METHODS

A cross-sectional online survey of parents with infants ≤12 months assessed parent-reported sleep practices: position, use of a separate sleep surface, and sleep location at 2 time points (sleep onset and after nighttime waking). A composite score examined if all 3 safe sleep practices were used at each time point. Safe sleep was defined as: supine position, sleeping in a separate space, and in a crib, bassinet, cradle, or playard. Wilcoxon sign rank test was used to examine changes between the time points. Poisson regression models compared parents who reported a second-sleep location with those who did not.

RESULTS

Of participants (n = 1500), 74% were female, 65% were White, 12% were Black, and 17% were of Hispanic ethnicity. Thirty-nine percent (n = 581) reported a second-sleep practice. Of parents who reported a second-sleep practice, 28% (n = 137) met all 3 safe sleep criteria at sleep onset; 9% (n = 42) met all 3 safe sleep criteria at both time points. A higher proportion of changes in sleep practices were to less-safe practices (P <.001). Factors associated with a second-sleep practice were parental age <25 years, parental race and ethnicity, first-time parents, homes with smoke exposure, and infants born at <37 weeks.

CONCLUSIONS

Less than 10% of infants met all 3 safe sleep criteria at sleep onset and after nighttime waking. Interventions focused on safe sleep should highlight the importance of safe sleep practices after nighttime waking.

Cardiac Causes of Sudden Unexpected Infant Death and the Role of the Primary Pediatrician

Sudden death of an infant can be from numerous causes. The leading cardiac causes include major congenital heart disease, myocarditis, cardiomyopathies, and channelopathies. There are new approaches to evaluating these patients and surviving family members. Pediatricians are a key component in support of the family, investigation of other at-risk family members, and coordination of subspecialty consultation. [Ped Ann. 2022;51(6):e228-e233.].

Harmful Effect of Intrauterine Smoke Exposure on Neuronal Control of "Fetal Breathing System" in Stillbirths

This article is aimed to contribute to the current knowledge on the role of toxic substances such as nicotine on sudden intrauterine unexplained deaths’ (SIUDS’) pathogenetic mechanisms. The in-depth histopathological examination of the autonomic nervous system in wide groups of victims of SIUDS (47 cases) and controls (20 cases), with both smoking and no-smoking mothers, highlighted the frequent presence of the hypodevelopment of brainstem structures checking the vital functions. In particular, the hypoplasia of the pontine parafacial nucleus together with hypoplastic lungs for gestational age were observed in SIUDS cases with mothers who smoked cigarettes, including electronic ones. The results allow us to assume that the products of cigarette smoke during pregnancy can easily cross the placental barrier, thus entering the fetal circulation and damaging the most sensitive organs, such as lungs and brain. In a non-negligible percentage of SIUDS, the mothers did not smoke. Furthermore, based on previous and ongoing studies conducted through analytical procedures and the use of scanning electron microscopy, the authors envisage the involvement of toxic nanoparticles (such as agricultural pesticides and nanomaterials increasingly used in biomedicine, bioscience and biotechnology) in the death pathogenesis, with similar mechanisms to those of nicotine.

Geneticists find clues to unexplained child deaths

Sequencing mysterious cases yields mutations linked to seizures and arrhythmias.

Association between auditory system pathology and sudden infant death syndrome (SIDS): a systematic review

OBJECTIVE

A theory has emerged, suggesting that abnormalities in the auditory system may be associated with sudden infant death syndrome (SIDS). However, current clinical evidence has never been systematically reviewed.

DESIGN

A systematic review was conducted according to the guideline of Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

DATA SOURCES

PubMed, Embase and Web of Science were systematically searched through 7 September 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Only human studies with a reference group were included. Studies were eligible for inclusion if they examined infants exposed to otoacoustic emissions (OAEs), auditory brainstem response (ABR) or had autopsies with brainstem histology of the auditory system. SIDS was the primary outcome, while the secondary outcome was near-miss sudden infant death syndrome episodes.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data and assessed risk of bias, and the quality of evidence. Due to high heterogeneity, a narrative synthesis was conducted. Risk of bias and quality of evidence was assessed using the Newcastle-Ottawa Scale and Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

Twelve case-control studies were included. Seven studies on OAEs or ABR had a high degree of inconsistency. Contrarily, four out of five studies reporting on brainstem histology found that auditory brainstem abnormalities were more prevalent in SIDS cases than in controls. However, the quality of evidence across all studies was very low.

CONCLUSION

This systematic review found no clear association between auditory system pathology and SIDS. The higher prevalence of histological abnormalities in the auditory system of SIDS may indicate an association. However, further studies of higher quality and larger study populations are needed to determine whether these findings are valid.

PROSPERO REGISTRATION NUMBER

CRD42020208045.

Characteristics That Distinguish Abusive From Nonabusive Causes of Sudden Unexpected Infant Deaths

BACKGROUND

Fatal child abuse can be mistaken for sudden unexpected infant death (SUID) in the emergency department setting. It is unknown if there are characteristics that distinguish abusive from nonabusive causes of SUIDs in the emergency department.

METHODS

Using a matched case-control design, we reviewed the medical examiner records of deaths of infants younger than 12 months who were found unresponsive at a residence, required cardiopulmonary resuscitation, and had a complete forensic autopsy between 2009 and 2015. Infants with a manner of death as homicide were cases; controls were those with the manner of death as accident, natural, or undetermined. Each case was matched with 5 controls based on age (months). Differences between cases and controls were evaluated with respect to demographic, parental, and household characteristics and clinical outcomes.

RESULTS

We identified 12 cases (homicides) and 169 controls (nonhomicides), of which 60 were selected for the matched analysis. We found no significant differences between cases and controls with respect to age, race, sex, maternal substance use, Child Protective Services involvement prior to death, presence of male head of household, surviving siblings, or emergency medical services transport. Cases were more likely to have Child Protective Services involvement at the time of death (83% vs 38%; P = 0.01), sentinel injuries (odds ratio, 9.67; 95% confidence interval, 1.30-122.43), and return of spontaneous circulation (odds ratio, 29.99; 95% confidence interval, 3.70-241.30).

CONCLUSIONS

Child Protective Services agency involvement at time of death, sentinel injury, and return of spontaneous circulation were more often associated with abusive causes of SUID. Further study is needed to confirm these findings.

Cultural variation in factors associated with sudden infant death during sleep

BACKGROUND

Despite the significant reduction decades ago in sudden unexpected death in infancy (SUDI), decline of rates has slowed and stalled in some countries, including the USA. This led to an appreciation of ethnic variations in SUDI rates and the need to increase cultural sensitivity regarding sleep practices and circumstantial factors of SUDI. The study explored SUDI-related factors, in journal articles from two geo-cultural regions (Asian and Western countries), particularly for factors related to infant sleep practices.

METHODS

A systematic review was conducted to identify SUDI-related factors in articles from PubMed, Scopus, and the Korean Citation Index from January 1992 to April 2019. From each article, SUDI-related factors were retrieved and categorized through the identification, aggregation, and categorization of factors into the areas of the triple risk model (TRM) of SUDI by their meanings and commonality. Significant trends in the frequency of factors were analyzed across time and between the two geo-cultural regions (Asian and Western countries) of article.

RESULTS

From a review of 218 articles (38 Asian and 180 Western articles), 84 SUDI-related factors were identified: 39 factors for TRM 1, 44 factors for TRM 2, and one factor for TRM 3. Four of the top-ranked 10 factors were found in both cultural zones: sleep position, male sex, bed-sharing, and genetics. Both cultural zones identified sleep position (44.0%), bed-sharing (22.0%), and rooming-in (16.5%) as the three most important sleep-related factors for SUDI. Variations between the cultural zones were observed in the place of SUDI occurrence, overheating, swaddling or bedding standards, and smoking.

CONCLUSIONS

Regardless of the urgent need to identify SUDI-related factors in low-SUDI societies, Asian cultures showed a significant lack of articles on SUDI. Several sociocultural issues were recognized such as the meaning of bed-sharing and rooming-in, along with residential styles and traditional health beliefs on sleep-related SUDI factors. Particularly little attention towards smoking was found in Asian articles in terms of frequency, suggesting the need to enhance SUDI reduction strategies by incorporating gender-sensitive smoking cessation interventions. This review of SUDI factors requests child health professionals to be alert to sociocultural variations in sleep practices and SUDI factors.

An Incidental Finding of Congenital Pulmonary Airway Malformation Type 3 During a Forensic Autopsy for a Sudden Infant Death: A Case Report With a Brief Literature Review

ABSTRACT

Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic airway malformation, is a developmental disorder of the lower respiratory tract. It is subdivided into 5 types based on clinical and pathologic features. Type 3, an adenomatoid type of CPAM, is the second rarest form of CPAM, occurring in approximately 5% of all CPAM cases. This article reports an autopsy of a nearly 11-week-old male infant, found unresponsive in bed with his mother. She had fallen asleep after breastfeeding a few hours prior. Although the autopsy and additional technical examinations did not uncover the exact cause of death, CPAM type 3 was eventually identified on histological examination. Taking into account the context of this case, in which accidental asphyxia/neglect could not be ruled out, it is thought that the presence of CPAM might have contributed to the demise of the infant. As CPAM is a rare congenital disorder, the diagnosis could easily be missed. Therefore, this article aims to raise awareness of this diagnosis and points out the clinical and pathologic features of this disorder.

Association between short-term exposure to air pollution and sudden infant death syndrome

The association between air pollution and infant mortality has been inconsistently reported. A few studies have estimated short-term effects of air pollution on infants' health. This population-based case-control study aimed to examine the potential effects of air pollution on sudden infant death syndrome (SIDS) in the post-neonatal period in Taiwan during 1997-2002. Each case of infant death was matched with 20 randomly selected sex-matched controls who were born on the same day and were still alive. We obtained 24-h measurements of air pollutants and meteorological factors in each case and control with 1- to 14-day lags from 55 air-quality monitoring stations. After controlling for potential confounders, conditional logistic regression analysis was performed to estimate effects of air pollutants on SIDS (n = 398) and respiratory death (n = 121) among neonates. In single- and multi-pollutant models, we found that 100-ppb increment in carbon monoxide (Odds Ratio = 1.04-1.07) and 10-ppb increment in nitrogen dioxide (Odds Ratio = 1.20-1.35) with 1- to 14-day lags were associated with significant increase in SIDS, although a significant relationship between air pollution and respiratory death was not determined in 1- to 14-day lags. Short-term carbon monoxide and nitrogen dioxide exposure were associated with significant increase in SIDS in the post-neonatal period, with latency estimated within days before death.

Explaining Sudden Unexpected Infant Deaths, 2011-2017

BACKGROUND

Sudden unexpected infant death (SUID) represents a broad group of explained and unexplained infant deaths (<1 year old). Explaining why SUID occurs is critical to understanding etiology and prevention. Death certificate data cannot differentiate explained from unexplained SUID cases nor describe the surrounding circumstances. We report SUID rates by explained and unexplained categories and describe demographics and history of recent injury or illness using the Centers for Disease Control and Prevention SUID Case Registry.

METHODS

The registry is a population-based surveillance system built on Child Death Review programs. Data are derived from multiple sources, including death certificates, scene investigations, and autopsy reports. Cases included SUIDs reported by states or jurisdictions participating in the registry during 2011-2017. Cases were classified into explained and unexplained categories by using the registry's classification system. Frequencies, percentages, and mortality rates per 100 000 live births were calculated.

RESULTS

Of the 4929 SUID cases, 82% were categorized as unexplained. Among all cases, 73% had complete case information. Most SUIDs (72%) occurred in an unsafe sleep environment. The SUID mortality rate was 97.3 per 100 000 live births. Among explained and possible suffocation deaths, ∼75% resulted from airway obstruction attributed to soft bedding.

CONCLUSIONS

Unsafe sleep factors were common in explained and unexplained SUID cases, but deaths could only be classified as explained suffocation for ∼20% of cases. Further analysis of unexplained deaths, including continued improvements to death scene investigation and documentation, may generate hypotheses for physiologic and genetic research, advance our understanding of gaps in SUID investigation, and enhance our understanding of infants at highest risk.

Talk to Patients About: Vaccines and SIDS

Over the years, several vaccines have been blamed for SIDS, including those for pertussis, tetanus, diphtheria, Hemophilus influenzae type B, polio, and hepatitis B. This misconception has triggered a lot of scientific study to find out if vaccines could, in fact, cause SIDS. However, multiple studies and safety reviews have concluded that the answer is no, according to the Centers for Disease Control and Prevention (CDC).

[Bad sleeping habits in infants: Risk factor for sudden infant death syndrome. Pilot study]

INTRODUCTION

The American Academy of Pediatrics recommends, through the implementation of the "Back to Sleep (BTS)" campaign, the supine sleeping position for infant sleeping since it prevents to prevent Sudden Infant Death Syndrome (SIDS).

OBJECTIVE

To describe the sleeping position of a group of infants and the risk factors associated with sudden infant death syndrome (SIDS).

SUBJECTS AND METHOD

Prospective pilot study, including infants < 45 days of life in well-child care visits at a medical center.

EXCLUSION CRITERIA

Preterm-born infant (gestational age < 37 weeks) and/or comorbidities (pulmonary, metabolic, cardiologic). A brief parental questionnaire was conducted regarding general demographic data and sleep habits. The questioner was based on the BISQ - Spanish version, due to the lack of validated instruments for infants < 3-month-old.

RESULTS

We included a sample of 100 infants between 16.78 ± 12.88 days old (57% girls). Mothers were the main information source (84%). 79% of the infants slept in supine position, 19% slept on their sides, and 2% in prone position. Regarding the place where the infants slept, 66% did in their crib in the parents' room and 31% slept in parents' bed. 74% of infants fell asleep while being fed. 28% of infants were exposed to passive smoking at home. 91% of parents were informed about safe sleep positions, reporting that pediatricians were the main source of information (54%). Conclu sion: We found a high percentage of infants < 45 days of life who slept in an unsafe position, and frequently co-sleep with their parents. Thus, it is important to implement local SIDS prevention campaigns to reinforce safe infant sleep.

SIDS, prone sleep position and infection: An overlooked epidemiological link in current SIDS research? Key evidence for the "Infection Hypothesis"

Mainstream researchers explain the etiology of SIDS with the cardiorespiratory paradigm. This has been the focus of intense study for many decades without providing consistent supporting data to link CNS findings to epidemiological risk factors or to the usual clinicopathological findings. Despite this, and the apparent oversight of the link between prone sleep position and respiratory infection, papers citing CNS, cardiac and sleep arousal findings continue to be published. Discovery of the prone sleep position risk factor provided tangential support for the cardiorespiratory control hypothesis which defines the mainstream approach. Despite many decades of research and huge expenditure, no aetiological answer has been forthcoming. In asking why?This paper exposes some of the shortcomings regarding this apparent oversight by mainstream SIDS researchers and examines the role of respiratory infection and puts the case for the “Infection Hypothesis.” In addition, the paper provides encouragement to neuropathologists to examine the potential link between CNS findings and cardiac function (as opposed to respiratory function) in relation to infection and to examine possible correlates between CNS findings and established risk factors such as recent infection, contaminated sleeping surfaces, maternal/obstetric/higher birth, ethnicity, non-breast-feeding, male gender, etc. or with the usual gross pathological findings of SIDS (intrathoracic petechial hemorrhages, liquid blood, congested lungs). The shortcomings exposed through this review invite questions over current research directions and hopefully encourage research into other more plausible hypotheses, such as the infection paradigm.•

Mainstream SIDS researchers appear to have overlooked the key relationship between prone sleep position and infection.

•

This omission has major implications for current and future SIDS research.