Bed-sharing in the first four months of life: a risk factor for sudden infant death

Qualitative assessment of infant sleep practices and other risk factors of sudden infant death syndrome (SIDS) among mothers in Lusaka, Zambia

BACKGROUND

There is very little information on the beliefs and perceptions of mothers about SIDS and its related risk factors in Africa. To better understand parental decisions about infant sleep practices and other risk factors for SIDS, we conducted focus group discussions (FGDs) with mothers of infants in Lusaka, Zambia.

METHODS

FGDs involved 35 purposively sampled mothers aged 18-49 years. FGDs were conducted using a semi-structured interview guide in the local language, Nyanja. These were translated, transcribed verbatim into English, and then coded and analyzed using thematic analysis in NVivo 12.

RESULTS

Six FGDs were conducted with 35 mothers in April-May 2021 across two study sites. FGD Participants were generally aware of sudden unexplained infant deaths, with several describing stories of apparent SIDS in the community. The side sleeping position was preferred and perceived to be safer for the infant with most believing the supine position posed an aspiration or choking risk to the infant. Bedsharing was also preferred and perceived to be convenient for breastfeeding and monitoring of the infant. Experienced family members such as grandmothers and mothers-in-law, and health care workers were frequently cited as sources of information on infant sleep position. A heightened awareness of the infant's sleeping environment was suggested as a mechanism to prevent SIDS and smothering.

CONCLUSIONS

Decisions about bedsharing and infant sleep position were guided by maternal beliefs and perceptions about what is convenient for breastfeeding and safer for the infant. These concerns are vital to designing tailored interventions to address sleep-related sudden infant losses in Zambia. Public health campaigns with tailored messages that address these concerns are likely to be effective at ensuring optimal uptake of safe sleep recommendations.

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.

Evidence Base for 2022 Updated Recommendations for a Safe Infant Sleeping Environment to Reduce the Risk of Sleep-Related Infant Deaths

Every year in the United States, approximately 3500 infants die of sleep-related infant deaths, including sudden infant death syndrome (SIDS) (International Statistical Classification of Diseases and Related Health Problems 10th Revision [ICD-10] R95), ill-defined deaths (ICD-10 R99), and accidental suffocation and strangulation in bed (ICD-10 W75). After a substantial decline in sleep-related deaths in the 1990s, the overall death rate attributable to sleep-related infant deaths have remained stagnant since 2000, and disparities persist. The triple risk model proposes that SIDS occurs when an infant with intrinsic vulnerability (often manifested by impaired arousal, cardiorespiratory, and/or autonomic responses) undergoes an exogenous trigger event (eg, exposure to an unsafe sleeping environment) during a critical developmental period. The American Academy of Pediatrics recommends a safe sleep environment to reduce the risk of all sleep-related deaths. This includes supine positioning; use of a firm, noninclined sleep surface; room sharing without bed sharing; and avoidance of soft bedding and overheating. Additional recommendations for SIDS risk reduction include human milk feeding; avoidance of exposure to nicotine, alcohol, marijuana, opioids, and illicit drugs; routine immunization; and use of a pacifier. New recommendations are presented regarding noninclined sleep surfaces, short-term emergency sleep locations, use of cardboard boxes as a sleep location, bed sharing, substance use, home cardiorespiratory monitors, and tummy time. In addition, additional information to assist parents, physicians, and nonphysician clinicians in assessing the risk of specific bed-sharing situations is included. The recommendations and strength of evidence for each recommendation are published in the accompanying policy statement, which is included in this issue.

Bed-Sharing in the First 6 Months: Associations with Infant-Mother Attachment, Infant Attention, Maternal Bonding, and Sensitivity at 18 Months

OBJECTIVE

The objective of this study was to investigate whether bed-sharing during the first 6 months of life is associated with infant's attachment and behavioral outcomes and mother's bonding and sensitive parenting at 18 months of age.

METHODS

The sample with complete longitudinal data comprised 178 infants and their caretakers. Bed-sharing was assessed with maternal report at term, 3, 6, and 18 months. Infant attachment was measured at 18 months using the strange situation procedure. Infant behavioral outcomes (i.e., poor attention/hyperactivity and task persistence) were assessed with 2 observational measures at 18 months. Maternal sensitivity was observed at 3 and 18 months, and mothers reported on bonding to their infant at term, 3, and 18 months.

RESULTS

Bed-sharing was common at term (41.2%), which decreased at 3 months (22.6%) followed by a slight increase at 6 (27.5%) and 18 months of age (31.3%). No associations between bed-sharing during the first 6 months and infant-mother attachment and infant behavioral outcomes at 18 months were found. Similarly, there were no associations between bed-sharing during the first 6 months and maternal bonding and sensitivity at consequent assessment points (i.e., 3 and 18 months).

CONCLUSION

Bed-sharing during the first 6 months is not associated with positive or negative outcomes about infant-mother attachment, infant behavior, maternal bonding, or sensitive parenting.

Hyperthermia and Heat Stress as Risk Factors for Sudden Infant Death Syndrome: A Narrative Review

BACKGROUND AND OBJECTIVES

Heat stress and hyperthermia are common findings in sudden infant death syndrome (SIDS) victims. It has been suggested that thermal stress can increase the risk of SIDS directly via lethal hyperthermia or indirectly by altering autonomic functions. Major changes in sleep, thermoregulation, cardiovascular function, and the emergence of circadian functions occur at the age at which the risk of SIDS peaks-explaining the greater vulnerability at this stage of development. Here, we review the literature data on (i) heat stress and hyperthermia as direct risk factors for SIDS, and (ii) the indirect effects of thermal loads on vital physiological functions.

RESULTS

Various situations leading to thermal stress (i.e., outdoors temperatures, thermal insulation from clothing and bedding, the prone position, bed-sharing, and head covering) have been analyzed. Hyperthermia mainly results from excessive clothing and bedding insulation with regard to the ambient thermal conditions. The appropriate amount of clothing and bedding thermal insulation for homeothermia requires further research. The prone position and bed-sharing do not have major thermal impacts; the elevated risk of SIDS in these situations cannot be explained solely by thermal factors. Special attention should be given to brain overheating because of the head's major role in body heat losses, heat production, and autonomic functions. Thermal stress can alter cardiovascular and respiratory functions, which in turn can lead to life-threatening events (e.g., bradycardia, apnea with blood desaturation, and glottal closure). Unfortunately, thermal load impairs the responses to these challenges by reducing chemosensitivity, arousability, and autoresuscitation. As a result, thermal load (even when not lethal directly) can interact detrimentally with vital physiological functions.

CONCLUSIONS

With the exception of excessive thermal insulation (which can lead to lethal hyperthermia), the major risk factors for SIDS appears to be associated with impairments of vital physiological functions when the infant is exposed to thermal stress.

Norwegian parents avoid placing infants in prone sleeping positions but frequently share beds in hazardous ways

AIM

Campaigns to prevent prone sleeping and other modifiable risk factors have greatly reduced the incidence of sudden infant death syndrome in Norway. Sleep-related infant deaths still occur sporadically and may be preventable. We studied infants' sleeping environments and whether parents followed safe sleep recommendations.

METHODS

Parents with infants up to 12 months of age were invited to complete an online questionnaire from May to December 2018. It was publicised by health centres and on websites and social media.

RESULTS

We received 4886 responses and 4150 met the age criteria and were included. Just under two-thirds (62.7%) reported routine bed-sharing, and this practice was associated with increased nocturnal breastfeeding, single parents and having more than one child. A small number of infants under six months were occasionally placed prone when they were laid down to sleep (2.1%) and 29.7% were placed on their side. Nearly three-quarters (72.6%) of the 2330 parents with infants under six months of age reported previous high-risk behaviour, such as sleeping together on a sofa or bed-sharing after smoking or drinking.

CONCLUSION

Norwegian parents rarely used prone sleeping positions for infants. However, bed-sharing was common, including high-risk scenarios such as smoking, alcohol use and sofas.

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.

Sudden Infant Death Syndrome: Beyond Risk Factors

Sudden infant death syndrome (SIDS) is defined as "the sudden death of an infant under 1 year of age which remains unexplained after thorough investigation including a complete autopsy, death scene investigation, and detailed clinical and pathological review". A significant decrease of SIDS deaths occurred in the last decades in most countries after the beginning of national campaigns, mainly as a consequence of the implementation of risk reduction action mostly concentrating on the improvement of sleep conditions. Nevertheless, infant mortality from SIDS still remains unacceptably high. There is an urgent need to get insight into previously unexplored aspects of the brain system with a special focus on high-risk groups. SIDS pathogenesis is associated with a multifactorial condition that comprehends genetic, environmental and sociocultural factors. Effective prevention of SIDS requires multiple interventions from different fields. Developing brain susceptibility, intrinsic vulnerability and early identification of infants with high risk of SIDS represents a challenge. Progress in SIDS research appears to be fundamental to the ultimate aim of eradicating SIDS deaths. A complex model that combines different risk factor data from biomarkers and omic analysis may represent a tool to identify a SIDS risk profile in newborn settings. If high risk is detected, the infant may be referred for further investigations and follow ups. This review aims to illustrate the most recent discoveries from different fields, analyzing the neuroanatomical, genetic, metabolic, proteomic, environmental and sociocultural aspects related to SIDS.

Sudden Infant Death Syndrome: A Review

Sudden infant death syndrome (SIDS) is the sudden unexpected death of an apparently healthy infant younger than age 12 months whose cause of death remains unknown despite a thorough death scene investigation, a review of the clinical history, and an autopsy. Despite the huge achievement of the Back to Sleep program, SIDS remains one of the leading causes of infant death in the United States. In recent years, the SIDS rate has remained stationary despite major public health efforts aimed at high-risk groups to improve sleep environment and strategies. This review focuses on SIDS epidemiology, pathogenesis and risk factors, the American Academy of Pediatrics recommendations on safe infant sleeping environment, and the US Centers for Disease Control and Prevention's multistate registry to improve knowledge on SIDS, evaluate trends, and analyze circumstances and events surrounding SIDS cases. [Pediatr Ann. 2018;47(3):e118-e123.].

Health Messaging and African-American Infant Sleep Location: A Randomized Controlled Trial

Infant-parent bedsharing increases the risk of SIDS and other sleep-related deaths. Despite AAP recommendations to avoid bedsharing, public health efforts have been unsuccessful in changing behaviors. African-American infants are more than twice as likely to die from SIDS and other sleep-related deaths, and are also twice as likely to bedshare with their parents. Further, African-American parents have a high degree of self-efficacy with regards to preventing infant suffocation, but low self-efficacy with regards to SIDS risk reduction. It is unclear whether messages emphasizing suffocation prevention will decrease bedsharing. To evaluate the impact of specific health messages on African-American parental decisions regarding infant sleep location. We conducted a randomized, controlled trial of African-American mothers of infants. The control group received standard messaging emphasizing AAP-recommended safe sleep practices, including avoidance of bedsharing, for the purposes of SIDS risk reduction. The intervention group received enhanced messaging emphasizing safe sleep practices, including avoidance of bedsharing, for both SIDS risk reduction and suffocation prevention. Participants completed interviews at 2-3 weeks, 2-3 months, and 5-6 months after the infant's birth. 1194 mothers were enrolled in the study, and 637 completed all interviews. Bedsharing, both usually (aOR 1.005 [95 % CI 1.003, 1.006]) and last night (aOR 1.004 [95 % CI 1.002, 1.007]) increased slightly but statistically significantly with infant age (p < 0.001). Receipt of the enhanced message did not impact on sleep location. Maternal belief that bedsharing increased the risk of SIDS or suffocation declined over 6 months (p < 0.001) and did not differ by group assignment. African-American mothers who received an enhanced message about SIDS risk reduction and suffocation prevention were no less likely to bedshare with their infants.

CLINICAL TRIALS REGISTRATION

Clinical Trials.gov identifier NCT01361880.

SIDS and Other Sleep-Related Infant Deaths: Evidence Base for 2016 Updated Recommendations for a Safe Infant Sleeping Environment

Approximately 3500 infants die annually in the United States from sleep-related infant deaths, including sudden infant death syndrome (SIDS), ill-defined deaths, and accidental suffocation and strangulation in bed. After an initial decrease in the 1990s, the overall sleep-related infant death rate has not declined in more recent years. Many of the modifiable and nonmodifiable risk factors for SIDS and other sleep-related infant deaths are strikingly similar. The American Academy of Pediatrics recommends a safe sleep environment that can reduce the risk of all sleep-related infant deaths. Recommendations for a safe sleep environment include supine positioning, use of a firm sleep surface, room-sharing without bed-sharing, and avoidance of soft bedding and overheating. Additional recommendations for SIDS risk reduction include avoidance of exposure to smoke, alcohol, and illicit drugs; breastfeeding; routine immunization; and use of a pacifier. New evidence and rationale for recommendations are presented for skin-to-skin care for newborn infants, bedside and in-bed sleepers, sleeping on couches/armchairs and in sitting devices, and use of soft bedding after 4 months of age. In addition, expanded recommendations for infant sleep location are included. The recommendations and strength of evidence for each recommendation are published in the accompanying policy statement, "SIDS and Other Sleep-Related Infant Deaths: Updated 2016 Recommendations for a Safe Infant Sleeping Environment," which is included in this issue.

Parent-child bed-sharing: The good, the bad, and the burden of evidence

The practice of parent and child sharing a sleeping surface, or 'bed-sharing', is one of the most controversial topics in parenting research. The lay literature has popularized and polarized this debate, offering on one hand claims of dangers, and on the other, of benefits - both physical and psychological - associated with bed-sharing. To address the scientific evidence behind such claims, we systematically reviewed 659 published papers (peer-reviewed, editorial pieces, and commentaries) on the topic of parent-child bed-sharing. Our review offers a narrative walkthrough of the many subdomains of bed-sharing research, including its many correlates (e.g., socioeconomic and cultural factors) and purported risks or outcomes (e.g., sudden infant death syndrome, sleep problems). We found general design limitations and a lack of convincing evidence in the literature, which preclude making strong generalizations. A heat-map based on 98 eligible studies aids the reader to visualize world-wide prevalence in bed-sharing and highlights the need for further research in societies where bed-sharing is the norm. We urge for multiple subfields - anthropology, psychology/psychiatry, and pediatrics - to come together with the aim of understanding infant sleep and how nightly proximity to the parents influences children's social, emotional, and physical development.

Breastfeeding Patterns in Preterm Infants Born at 28-33 Gestational Weeks

BACKGROUND

Studies of breastfeeding patterns during preterm infants' first year of life are scarce but are important for providing breastfeeding mothers of preterm infants with optimal support.

OBJECTIVE

This study aimed to describe breastfeeding patterns in preterm infants up to 1 year of corrected age.

METHODS

As part of a larger study on kangaroo mother care in Sweden, a 24-hour breastfeeding diary was sent home after discharge from hospital, and at 2, 6, and 12 months of the infant's corrected age. Eighty-three mothers responded to the follow-up questionnaires, and the number of respondents to the breastfeeding diary was 48 at discharge, 43 at 2 months, 22 at 6 months, and 8 at 12 months. Infants were born at a median (range) gestational age of 32 (28-33) weeks. Breastfeeding patterns were analyzed according to durations, frequencies per 24 hours, and intervals between sessions.

RESULTS

In exclusively breastfed infants, the median (range) breastfeeding session frequency was 14 (8-26) times per 24 hours including 4 (1-9) times per night after discharge (n = 24) and 10 (6-25) times per 24 hours including 2 (0-5) times per night at 2 months (n = 23). In partially breastfed infants, the median (range) frequency was 5 (1-14) times per 24 hours including 2 (0-4) times per night at 6 months (n = 20) and 5.5 (1-12) times per 24 hours including 2 (0-3) times per night at 12 months (n = 8).

CONCLUSION

Mothers reported large variations in breastfeeding patterns, with higher median breastfeeding session frequencies than previously described in term infants in affluent settings.

Making the first days of life safer: preventing sudden unexpected postnatal collapse while promoting breastfeeding

Early and prolonged skin-to-skin contact (SSC) after birth between a mother and her newborn has been shown to generate beneficial effects on the mother-infant relationship and breastfeeding. Close mother-infant body contact immediately after birth positively enhances exclusive breastfeeding during the hospital stay, with a dose-response relationship. Skin-to-skin contact may ease the infant's transition to extra-uterine life and helps regulate the infant's body temperature and nursing behavior. However, reports of sudden unexpected postnatal collapse (SUPC) soon after birth, in healthy term neonates, in association with SSC, have raised concerns about the safety of this practice. Based on available evidence, we developed a surveillance protocol in the delivery room and postnatal ward of the Institute for Maternal and Child Health of Trieste (Italy). The aim of our protocol is (a) to promote safe mother and infant bonding and (b) to establish successful breastfeeding, without increasing the risk of SUPC. As there is no known effective intervention to prevent SUPC, our protocol has been conceived as a potential best practice.

Sudden unexpected death in infancy: biological mechanisms

Sudden unexpected death in infancy (SUDI) covers both explained and unexplained deaths. Unexplained cases or SIDS are likely to have multiple neural mechanisms contributing to the final event. The evidence ranges from subtle physiological signs related to autonomic control, to findings at autopsy of altered neurotransmitter systems, including the serotonergic system, a network that has an extensive homeostatic role in cardio-respiratory and thermoregulatory control. Processes may be altered by the vulnerability of the infant due to age, poor motor ability, or a genetic predisposition. The fatal event may occur in response to an environmental stress. A single final physiological route to death seems unlikely. An understanding of the reasons for explained SUDI also reminds us that a thorough investigation is required after each death occurs.

Sleep environment risks for younger and older infants

OBJECTIVE

Sudden infant death syndrome and other sleep-related causes of infant mortality have several known risk factors. Less is known about the association of those risk factors at different times during infancy. Our objective was to determine any associations between risk factors for sleep-related deaths at different ages.

METHODS

A cross-sectional study of sleep-related infant deaths from 24 states during 2004-2012 contained in the National Center for the Review and Prevention of Child Deaths Case Reporting System, a database of death reports from state child death review teams. The main exposure was age, divided into younger (0-3 months) and older (4 months to 364 days) infants. The primary outcomes were bed-sharing, objects in the sleep environment, location (eg, adult bed), and position (eg, prone).

RESULTS

A total of 8207 deaths were analyzed. Younger victims were more likely bed-sharing (73.8% vs. 58.9%, P < .001) and sleeping in an adult bed/on a person (51.6% vs. 43.8%, P < .001). A higher percentage of older victims had an object in the sleep environment (39.4% vs. 33.5%, P < .001) and changed position from side/back to prone (18.4% vs. 13.8%, P < .001). Multivariable regression confirmed these associations.

CONCLUSIONS

Risk factors for sleep-related infant deaths may be different for different age groups. The predominant risk factor for younger infants is bed-sharing, whereas rolling into objects in the sleep area is the predominant risk factor for older infants. Parents should be warned about the dangers of these specific risk factors appropriate to their infant's age.

Deaths and near deaths of healthy newborn infants while bed sharing on maternity wards

OBJECTIVE

Our aim was to evaluate programs promoting bed sharing on maternity wards and determining ways to reduce these risks.

STUDY DESIGN

Members of the National Association of Medical Examiners were contacted requesting information on deaths of healthy infants while bed sharing on maternity wards.

RESULT

Fifteen deaths and three near deaths are reported. One or more factors that increase the risk of bed sharing were present in all cases. Accidental suffocation was deemed the most likely cause of these incidents.

CONCLUSION

Cases of infant deaths and near deaths while bed sharing on maternity wards are under reported. The 'Baby Friendly' (BF) initiative in maternity hospitals to promote breastfeeding is endorsed by the American Academy of Pediatrics and the US Center for Disease Control and Prevention. The BF initiative encourages prolonged skin-to-skin contact and bed sharing. Education of mothers and more efficient monitoring should significantly reduce the risk of maternity ward bed sharing.

Is "Bed Sharing" Beneficial and Safe during Infancy? A Systematic Review

Background. There is conflicting evidence regarding the safety and efficacy of bed sharing during infancy-while it has been shown to facilitate breastfeeding and provide protection against hypothermia, it has been identified as a risk factor for SIDS. Methods. A systematic search of major databases was conducted. Eligible studies were observational studies that enrolled infants in the first 4 weeks of life and followed them up for a variable period of time thereafter. Results. A total of 21 studies were included. Though the quality of evidence was low, bed sharing was found to be associated with higher breastfeeding rates at 4 weeks of age (75.5% versus 50%, OR 3.09 (95% CI 2.67 to 3.58), P = 0.043) and an increased risk of SIDS (23.3% versus 11.2%, OR 2.36 (95% CI 1.97 to 2.83), P = 0.025). Majority of the studies were from developed countries, and the effect was almost consistent across the studies. Conclusion. There is low quality evidence that bed sharing is associated with higher breast feeding rates at 4 weeks of age and an increased risk of SIDS. We need more studies that look at bed sharing, breast feeding, and hazardous circumstance that put babies at risk.

Patterns of infant mortality in Kuwait from 2003 to 2006

Infant death is often tragic, particularly in the Arab World, where infants, especially males, are supposed to carry their family's names due to ancient cultural traditions. The conditions and events that may be associated with infant death are extremely varied. Infants may die from either congenital disorders or natural diseases, or may pass away as a consequence of a complicated delivery. Infants are also victims of accidents and violence such as homicides. The main aim of this study was to investigate the reported medico legal cases of infant mortality in Kuwait due to natural and un-natural causes between 2003 and 2006. The average IMR rate in Kuwait during the study period was better than the IMR average for developing countries and the IMR average for the world during the same study period. In general, these figures for Kuwait are even better than the average for Middle East and North Africa. More medico- legal cases were reported for deaths among Kuwaiti infants in 2004, 2005 and 2006 compared to non Kuwaiti infants. More Kuwaiti infants died due to RTA and domestic accidents. In contrast, only non Kuwaiti infant died from infanticide.

Bed sharing when parents do not smoke: is there a risk of SIDS? An individual level analysis of five major case-control studies

OBJECTIVE

To resolve uncertainty as to the risk of Sudden Infant Death Syndrome (SIDS) associated with sleeping in bed with your baby if neither parent smokes and the baby is breastfed.

DESIGN

Bed sharing was defined as sleeping with a baby in the parents' bed; room sharing as baby sleeping in the parents' room. Frequency of bed sharing during last sleep was compared between babies who died of SIDS and living control infants. Five large SIDS case-control datasets were combined. Missing data were imputed. Random effects logistic regression controlled for confounding factors.

SETTING

Home sleeping arrangements of infants in 19 studies across the UK, Europe and Australasia.

PARTICIPANTS

1472 SIDS cases, and 4679 controls. Each study effectively included all cases, by standard criteria. Controls were randomly selected normal infants of similar age, time and place.

RESULTS

In the combined dataset, 22.2% of cases and 9.6% of controls were bed sharing, adjusted OR (AOR) for all ages 2.7; 95% CI (1.4 to 5.3). Bed sharing risk decreased with increasing infant age. When neither parent smoked, and the baby was less than 3 months, breastfed and had no other risk factors, the AOR for bed sharing versus room sharing was 5.1 (2.3 to 11.4) and estimated absolute risk for these room sharing infants was very low (0.08 (0.05 to 0.14)/1000 live-births). This increased to 0.23 (0.11 to 0.43)/1000 when bed sharing. Smoking and alcohol use greatly increased bed sharing risk.

CONCLUSIONS

Bed sharing for sleep when the parents do not smoke or take alcohol or drugs increases the risk of SIDS. Risks associated with bed sharing are greatly increased when combined with parental smoking, maternal alcohol consumption and/or drug use. A substantial reduction of SIDS rates could be achieved if parents avoided bed sharing.

Sudden infant death syndrome in Korea: a retrospective analysis of autopsy-diagnosed cases

This study aimed to elucidate the demographic and sleeping environmental factors associated with sudden infant death syndrome (SIDS) in Korea. The autopsy reports of all SIDS cases reported to the National Forensic Service and Seoul National University College of Medicine between 1996 and 2008 were reviewed for data collection and analysis to identify the risk factors for SIDS. Analysis of the 355 SIDS cases reported within the study period revealed that of the 168 (47.3%) cases for which sleeping position before death had been reported, 75 (44.7%) cases had occurred after placement in prone or side position. Of the 204 (57.5%) cases for which bed-sharing situation had been reported, 121 (59.3%) deaths had occurred during bed-sharing, of which 54 (44.6%) infants were under 3 months of age, a significantly younger age than that of the non-bed-sharing cases (P = 0.0279). Analysis of the results indicated no tendency toward an increase or decrease in the use of a prone or side position. Rather, there was a statistically significant increasing trend for bed-sharing over the study period (OR, 1.087; 95% CI, 1.004-1.177; P = 0.04). These findings indicate the need for nationwide educational programs promoting a safe sleeping environment to enhance SIDS prevention.

Cardiac ion channelopathies and the sudden infant death syndrome

The sudden infant death syndrome (SIDS) causes the sudden death of an apparently healthy infant, which remains unexplained despite a thorough investigation, including the performance of a complete autopsy. The triple risk model for the pathogenesis of SIDS points to the coincidence of a vulnerable infant, a critical developmental period, and an exogenous stressor. Primary electrical diseases of the heart, which may cause lethal arrhythmias as a result of dysfunctioning cardiac ion channels (“cardiac ion channelopathies”) and are not detectable during a standard postmortem examination, may create the vulnerable infant and thus contribute to SIDS. Evidence comes from clinical correlations between the long QT syndrome and SIDS as well as genetic analyses in cohorts of SIDS victims (“molecular autopsy”), which have revealed a large number of mutations in ion channel-related genes linked to inheritable arrhythmogenic syndromes, in particular the long QT syndrome, the short QT syndrome, the Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia. Combining data from population-based cohort studies, it can be concluded that at least one out of five SIDS victims carries a mutation in a cardiac ion channel-related gene and that the majority of these mutations are of a known malignant phenotype.

Autopsy findings of co-sleeping-associated sudden unexpected deaths in infancy: relationship between pathological features and asphyxial mode of death

AIM

Co-sleeping is associated with increased risk of sudden unexpected death in infancy (SUDI)/sudden infant death syndrome (SIDS). The aim of this study is to examine autopsy findings from a single U.K. specialist centre to determine the relationship between co-sleeping and cause of death.

METHODS

Retrospective analysis of >1500 paediatric autopsies carried out by paediatric pathologists over a 10-year period. SUDI was defined as sudden unexpected death of an infant aged 7-365 days; deaths were categorised into explained SUDI (cause of death was determined) and unexplained SUDI (equivalent to SIDS).

RESULTS

There were 546 SUDI; sleeping arrangements were specifically recorded in 314; of these, 174 (55%) were co-sleeping-associated deaths. Almost two thirds (59%) of unexplained SUDI were co-sleeping compared to 44% explained SUDI (95% confidence interval (CI) 1.0-27.2%, P=0.03); however, this difference remained statistically significant only for the first 5 months of life (95% CI 3.5-33.2%, P=0.01). In unexplained SUDI aged < 6 months, there were no significant differences between co-sleeping and non-co-sleeping deaths with respect to ante-mortem symptoms, intrathoracic petechiae, macroscopic lung appearances, pulmonary haemosiderin-laden macrophages, and isolation of specific bacterial pathogens; however, fresh intra-alveolar haemorrhage was reported more commonly in co-sleeping (54%) than in those that were not (38%; 95% CI 1.4-30.5%, P=0.03).

CONCLUSIONS

Co-sleeping is associated with unexplained SUDI/SIDS in infants aged < 6 months, suggesting that co-sleeping is related to the pathogenesis of death in younger infants. The finding that intra-alveolar haemorrhage is more common in co-sleeping suggests that a minority of co-sleeping-associated deaths may be related to an asphyxial process.

Risk factor changes for sudden infant death syndrome after initiation of Back-to-Sleep campaign

OBJECTIVE

To test the hypothesis that the profile of sudden infant death syndrome (SIDS) changed after the Back-to-Sleep (BTS) campaign initiation, document prevalence and patterns of multiple risks, and determine the age profile of risk factors.

METHODS

The San Diego SIDS/Sudden Unexplained Death in Childhood Research Project recorded risk factors for 568 SIDS deaths from 1991 to 2008 based upon standardized death scene investigations and autopsies. Risks were divided into intrinsic (eg, male gender) and extrinsic (eg, prone sleep).

RESULTS

Between 1991-1993 and 1996-2008, the percentage of SIDS infants found prone decreased from 84.0% to 48.5% (P < .001), bed-sharing increased from 19.2% to 37.9% (P < .001), especially among infants <2 months (29.0% vs 63.8%), prematurity rate increased from 20.0% to 29.0% (P = .05), whereas symptoms of upper respiratory tract infection decreased from 46.6% to 24.8% (P < .001). Ninety-nine percent of SIDS infants had at least 1 risk factor, 57% had at least 2 extrinsic and 1 intrinsic risk factor, and only 5% had no extrinsic risk. The average number of risks per SIDS infant did not change after initiation of the BTS campaign.

CONCLUSIONS

SIDS infants in the BTS era show more variation in risk factors. There was a consistently high prevalence of both intrinsic and especially extrinsic risks both before and during the Back-to-Sleep era. Risk reduction campaigns emphasizing the importance of avoiding multiple and simultaneous SIDS risks are essential to prevent SIDS, including among infants who may already be vulnerable.

Bed- and sofa-sharing practices in a UK biethnic population

OBJECTIVE

To describe the prevalence and associations of bed- and sofa-sharing in a biethnic UK birth cohort.

METHODS

We surveyed 3082 participants in the Born in Bradford birth cohort study by using a telephone interview when infants were aged 2 to 4 months. We asked families about sleep surface sharing behaviors, and other sudden unexpected death in infancy (SUDI)-related behaviors.

RESULTS

There were 15.5% of families that had ever bed-shared, 7.2% of families regularly bed-shared, and 9.4% of families had ever sofa-shared with their infants; 1.4% reported both. Regular bed-sharers were more commonly Pakistani (adjusted odds ratio [aOR] = 3.02, 95% confidence interval [CI] 1.96-4.66), had further or higher educational qualifications (aOR = 1.62, 95% CI 1.03-2.57), or breastfed for at least 8 weeks (aOR = 3.06, 95% CI 2.00-4.66). The association between breastfeeding and bed-sharing was greater among white British than Pakistani families. Sofa-sharing occurred in association with smoking (aOR = 1.79, 95% CI 1.14-2.80) and breastfeeding for more than 8 weeks (aOR = 1.76, 95% CI 1.19-2.58), and was less likely in Pakistani families (aOR = 0.21, 95% CI 0.14-0.31), or single-parent families (aOR = 0.50, 95% CI 0.29-0.87).

CONCLUSIONS

The data confirm that bed-sharing and sofa-sharing are distinct practices, which should not be combined in studies of unexpected infant deaths as a single exposure. The determinants of sleep-surface sharing differ between the UK Pakistani and UK majority communities, and from those of US minority communities. Caution is needed in generalizing SUDI/SIDS risk factors across populations with differing risk factor profiles, and care should be taken in adopting SUDI/SIDS reduction guidelines from other contexts.

Gliosis in neonatal SUDI cases

AIM

To review sudden unexpected infant deaths (SUDI) in the first 28 days of life referred to a Coronial Perinatal Forensic Pathology Service over a 10-year period from 2000 to 2009.

METHODS

Cases were collected from mortuary records, and a retrospective review of autopsy reports and other available infant records was undertaken.

RESULTS

Twenty-four neonatal SUDI were reviewed. For eight infants, a diagnosis was made at autopsy. For the remaining 16 infants, 14 (87.5%) were bedsharing at the time of death. Maori infants and those living in deprived neighbourhoods were over-represented. Only two infants were preterm, and four were growth-restricted. At post-mortem, white matter gliosis was found in 10 of the 16 (62.5%) unexplained SUDI cases.

CONCLUSION

Sudden unexpected infant deaths occur in the first month of life in association with bedsharing. Gliosis may be an important associated risk factor, and its presence indicates a previous insult of prenatal onset.

SIDS and other sleep-related infant deaths: expansion of recommendations for a safe infant sleeping environment

Despite a major decrease in the incidence of sudden infant death syndrome (SIDS) since the American Academy of Pediatrics (AAP) released its recommendation in 1992 that infants be placed for sleep in a nonprone position, this decline has plateaued in recent years. Concurrently, other causes of sudden unexpected infant death occurring during sleep (sleep-related deaths), including suffocation, asphyxia, and entrapment, and ill-defined or unspecified causes of death have increased in incidence, particularly since the AAP published its last statement on SIDS in 2005. It has become increasingly important to address these other causes of sleep-related infant death. Many of the modifiable and nonmodifiable risk factors for SIDS and suffocation are strikingly similar. The AAP, therefore, is expanding its recommendations from being only SIDS-focused to focusing on a safe sleep environment that can reduce the risk of all sleep-related infant deaths including SIDS. The recommendations described in this report include supine positioning, use of a firm sleep surface, breastfeeding, room-sharing without bed-sharing, routine immunization, consideration of a pacifier, and avoidance of soft bedding, overheating, and exposure to tobacco smoke, alcohol, and illicit drugs. The rationale for these recommendations is discussed in detail in this technical report. The recommendations are published in the accompanying "Policy Statement--Sudden Infant Death Syndrome and Other Sleep-Related Infant Deaths: Expansion of Recommendations for a Safe Infant Sleeping Environment," which is included in this issue (www.pediatrics.org/cgi/doi/10.1542/peds.2011-2220).

Formative evaluation to improve prevention of sudden infant death syndrome (SIDS): a prospective study

AIM

To evaluate formative evaluation, a pedagogic method that sensitizes mothers to sudden infant death syndrome (SIDS), as a new way to improve prevention of SIDS.

METHODS

Prospective and randomized study. Mothers in a test group (n = 148) received an educative questionnaire about SIDS during maternity stay. Three months later, we evaluated, by a telephonic interview, their scores of knowledge and observance of the recommendations in comparison with a control group (n = 144).

RESULTS

Mothers' scores at the educative questionnaire was 5.12 (1.52) [mean(standard deviation)]. The scores performed 3 months later were better in test group for knowledge [7.64 (1.56) vs. 7.16 (1.61), p < 0.01] and for observance [8.28 (1.51) vs. 7.62 (1.72), p < 0.001]. Logistic regression analysis confirmed the benefits in test group regarding knowledge of SIDS risk factors [ORa = 1.69 (1.02-2.77), p < 0.05], of the advice to avoid overheating infants [ORa = 2.50 (1.43-4.38), p < 0.01] and of the risks of bed sharing [ORa = 2.7 (1.6-4.5), p < 0.001]. There was a significant association between non-compliance with the sleeping position recommendation and unemployment (p < 0.01) and absence of postsecondary school education (p < 0.01).

CONCLUSION

Formative evaluation using an educative questionnaire could improve maternal awareness on SIDS risk factors and their compliance with recommendations about SIDS prevention.

Breastfeeding and reduced risk of sudden infant death syndrome: a meta-analysis

CONTEXT

Benefits of breastfeeding include lower risk of postneonatal mortality. However, it is unclear whether breastfeeding specifically lowers sudden infant death syndrome (SIDS) risk, because study results have been conflicting.

OBJECTIVE

To perform a meta-analysis to measure the association between breastfeeding and SIDS.

METHODS

We identified 288 studies with data on breastfeeding and SIDS through a Medline search (1966-2009), review articles, and meta-analyses. Twenty-four original case-control studies were identified that provided data on the relationship between breastfeeding and SIDS risk. Two teams of 2 reviewers evaluated study quality according to preset criteria; 6 studies were excluded, which resulted in 18 studies for analysis. Univariable and multivariable odds ratios were extracted. A summary odds ratio (SOR) was calculated for the odds ratios by using the fixed-effect and random-effect inverse-variance methods of meta-analysis. The Breslow-Day test for heterogeneity was performed.

RESULTS

For infants who received any amount of breast milk for any duration, the univariable SOR was 0.40 (95% confidence interval [CI]: 0.35-0.44), and the multivariable SOR was 0.55 (95% CI: 0.44-0.69). For any breastfeeding at 2 months of age or older, the univariable SOR was 0.38 (95% CI: 0.27-0.54). The univariable SOR for exclusive breastfeeding of any duration was 0.27 (95% CI: 0.24-0.31).

CONCLUSIONS

Breastfeeding is protective against SIDS, and this effect is stronger when breastfeeding is exclusive. The recommendation to breastfeed infants should be included with other SIDS risk-reduction messages to both reduce the risk of SIDS and promote breastfeeding for its many other infant and maternal health benefits.

Bed-sharing among six-month-old infants in western Sweden

AIM

In spite of several reports of an increased risk of sudden infant death syndrome (SIDS) in connection with bed-sharing, it is not an uncommon practice. The aim of this study was to examine bed-sharing at 6 months of age and the factors that are associated with bed-sharing.

METHODS

Our cohort comprised 8176 randomly chosen families. At 6 month of age, the families received an invitation to the study, with a questionnaire, which was completed by 5605 families (response rate 68.5%).

RESULTS

Of the families, 19.8% bed-shared. In the multivariate analysis, we found a correlation between breast-feeding and bed-sharing (breast-feeding at 6 months: OR 1.94; 95% CI 1.56, 2.41). Moreover, we found an association with 3+ nightly awakenings at 6 months (2.70; 2.20, 3.32). It was more common to share a bed if the parent was single (2.04; 1.19, 3.51) and less common if the infant was bottle-fed in the first week (0.70; 0.54, 0.90). Never using a pacifier was associated with a higher frequency of bed-sharing.

CONCLUSION

We found a correlation between breast-feeding and bed-sharing as well as between sleeping problems and a single parent. A lower percentage of infants sleeping in the parental bed were seen in association with formula feeding in the first week after birth.

Where should my baby sleep: a qualitative study of African American infant sleep location decisions

BACKGROUND

African American infants are of higher risk for sudden infant death syndrome (SIDS) and accidental suffocation than other infants and are up to 4 times more likely to bedshare with their parents.

OBJECTIVE

To investigate, using qualitative methods, factors influencing African American parents' decisions regarding infant sleep location (room location and sleep surface).

METHODS

Eighty-three mothers participated in focus groups or individual interviews. Questions probed reasons for infant sleep location decisions and influences on decision making.

RESULTS

Most of the mothers in this study slept in the same room as their infant. Reasons for roomsharing included space, convenience, and safety. Mothers largely decided on infant sleep surface because of space for/availability of crib, comfort, convenience, and safety. Both roomsharing and bedsharing were often chosen to make feeding and checking on the infant more convenient. Mothers who chose not to bedshare cited privacy, concern that the infant would become attached to the parents' bed, and fears about suffocation. Mothers who chose to bedshare often cited the ability to maintain vigilance while asleep. Low-income mothers also used bedsharing as a defense against environmental dangers.

CONCLUSION

African American mothers in this study viewed both roomsharing and bedsharing as strategies to keep their infants safe. Efforts to encourage roomsharing without bed-sharing must address parental concerns about space for/ availability of a crib, convenience, infant and parent comfort, and infant safety.

Bed sharing among black infants and sudden infant death syndrome: interactions with other known risk factors

OBJECTIVE

Bed sharing has been associated with sudden infant death syndrome (SIDS) and may contribute to the racial disparity seen in infant mortality. It is unclear how bed sharing interacts with other factors to impact SIDS risk. We aimed to measure the effects of bed sharing on risk of SIDS in blacks and to determine whether the risk is modified by other characteristics of the sleep environment.

METHODS

Characteristics of 195 black infants who died of SIDS were compared with matched controls. The moderating influence of known SIDS risk factors on the effect of bed sharing on risk of SIDS was examined using logistic regression.

RESULTS

Almost half (47.4%) of the study population bed shared during the last/reference sleep (58% cases and 37% controls). Bed sharing was associated with 2 times greater risk of SIDS compared with not bed sharing. The deleterious effect of bed sharing was more pronounced with a soft sleep surface, pillow use, maternal smoking, and younger infant age. However, bed sharing was still associated with an increased risk of SIDS, even when the infant was not using a pillow or sleeping on a firm surface. The strongest predictors of SIDS among bed-sharing infants were soft sleep surface, nonuse of a pacifier, and maternal smoking during pregnancy.

CONCLUSIONS

Bed sharing is a common practice among black infants. It is associated with a clear and strong increased risk of SIDS, which is even greater when combined with other known risk factors for SIDS. This practice likely contributes to the excess incidence of SIDS among blacks, and culturally competent education methods must be developed to target this high-risk group.

Virological investigations in sudden unexpected deaths in infancy (SUDI)

Previous studies have implicated viral infections in the pathogenesis of sudden unexpected death in infancy (SUDI), and routine virological investigations are recommended by current SUDI autopsy protocols. The aim of this study is to determine the role of post-mortem virology in establishing a cause of death. A retrospective review of 546 SUDI autopsies was carried out as part of a larger series of >1,500 consecutive paediatric autopsies performed over a 10-year period, 1996-2005, in a single specialist centre. Virological tests were performed as part of the post-mortem examination in 490 (90%) of the 546 SUDI autopsies, comprising 4,639 individual virological tests, of which 79% were performed on lung tissue samples. Diagnostic methods included immunofluorescence assays (using a routine respiratory virus panel; 98% of cases), cell culture (61%), rapid culture techniques such as the DEAFF test for CMV (55%), PCR (13%), electron microscopy (10%), and others. Virus was identified in only 18 cases (4%), viz. five cases of enterovirus, four of RSV, three of HSV and CMV, and one each of adenovirus, influenza virus and HIV. In seven of the 18 cases the death was classified as due to viral infection, whilst of the remaining 11 cases, death was due to bacterial infection in five, a non-infective cause in one and unexplained in five. Virus was identified in 33% of deaths due to probable viral infections, but also in 6% of SUDI due to bacterial infections, and in 2% of SUDI due to known non-infective causes and unexplained SUDI. When predominantly using immunofluorescence, virus is identified in only a small proportion of SUDI autopsies, resulting in a contribution to the final cause of death in <2% of SUDI post-mortem examinations. Routine post-mortem virological analysis by means of an immunofluorescence respiratory virus panel appears to be of limited benefit in SUDI for the purposes of determining cause of death. Application of a broader panel using more sensitive detection techniques may reveal more viruses, although their contribution to the final cause of death requires further exploration.

Infant sleep location: associated maternal and infant characteristics with sudden infant death syndrome prevention recommendations

OBJECTIVE

To identify factors associated with infant sleep location.

STUDY DESIGN

Demographic information and infant care practices were assessed for 708 mothers of infants ages 0 to 8 months at Women, Infants and Children centers. Generalized linear latent mixed models were constructed for the outcome, sleeping arrangement last night (room-sharing without bed-sharing versus bed-sharing, and room-sharing without bed-sharing versus sleeping in separate rooms).

RESULTS

Two-thirds of the mothers were African-American. A total of 48.6% mothers room-shared without bed-sharing, 32.5% bed-shared, and 18.9% slept in separate rooms. Compared with infants who slept in separate rooms, infants who room-shared without bed-sharing were more likely to be Hispanic (odds ratio [OR], 2.58, 95% CI 1.11-5.98) and younger (3.66- and 1.74-times more likely for infants 0-1 month old and 2-3 months old, respectively, as compared with older infants). Compared with infants who bed-shared, infants who room-shared without bed-sharing were more likely to be 0 to 1 month old (OR, 1.57; 95% CI, 1.05-2.35) and less likely to be African-American (OR, 0.43; 95% CI, 0.26-0.70) or have a teenage mother (OR, 0.37; 95% CI, 0.23-0.58).

CONCLUSIONS

Approximately one-third of mothers and infants bed-share, despite increased risk of sudden infant death syndrome (SIDS). The factors associated with bed-sharing are also associated with SIDS, likely rendering infants with these characteristics at high risk for SIDS.