Side sleeping position and bed sharing in the sudden infant death syndrome

Death from Failed Protection? An Evolutionary-Developmental Theory of Sudden Infant Death Syndrome

Sudden infant death syndrome (SIDS) has been mainly described from a risk perspective, with a focus on endogenous, exogenous, and temporal risk factors that can interact to facilitate lethal outcomes. Here we discuss the limitations that this risk-based paradigm may have, using two of the major risk factors for SIDS, prone sleep position and bed-sharing, as examples. Based on a multipronged theoretical model encompassing evolutionary theory, developmental biology, and cultural mismatch theory, we conceptualize the vulnerability to SIDS as an imbalance between current physiologic-regulatory demands and current protective abilities on the part of the infant. From this understanding, SIDS appears as a developmental condition in which competencies relevant to self-protection fail to develop appropriately in the future victims. Since all of the protective resources in question are bound to emerge during normal infant development, we contend that SIDS may reflect an evolutionary mismatch situation-a constellation in which certain modern developmental influences may overextend the child's adaptive (evolutionary) repertoire. We thus argue that SIDS may be better understood if the focus on risk factors is complemented by a deeper appreciation of the protective resources that human infants acquire during their normal development. We extensively analyze this evolutionary-developmental theory against the body of epidemiological and experimental evidence in SIDS research and thereby also address the as-of-yet unresolved question of why breastfeeding may be protective against SIDS.

[Gastroesophageal reflux and sleep position of infants. A survey conducted in France by 493 pediatricians]

BACKGROUND AND AIMS

The supine sleeping position with the head higher than the legs has no impact on regurgitations in infants. Inclined ventral decubitus decreases regurgitations but is associated with an increased risk of sudden infant death syndrome (SIDS). The LUNE study aimed to evaluate the impact of regurgitations on the choice of sleeping position by pediatricians and parents.

METHODS

Cross-sectional case-control study (ratio 1:1) conducted in France in 2013. A representative sample of pediatricians recruited 3-week to 4-month-old breast- or formula-fed infants. Cases and controls were defined by the presence or absence of regurgitations. Collected data included Vandenplas codification for regurgitations (VD, range 0-6), associated symptoms, and variations in sleeping position since maternity hospital discharge.

RESULTS

A total of 1347 cases and 1346 controls were recruited by 493 pediatricians. Regurgitations were evaluated at VD1 (minor, 22 % of cases), VD2 (mild, 47 % of cases), or VD≥3 (moderate to severe, 31 % of cases). At the maternity hospital, the supine position was recommended to 96 % of parents for SIDS prevention. Since discharge, parents asked questions about the relationship between sleeping position and regurgitations (79 % of infants with GER versus 45 % of controls). The sleeping position was modified at least once since maternity discharge (42 % of infants with GER versus 35 % of controls). At inclusion, 86 % of infants with GER and 86 % of controls were sleeping on their back. Fifty-one percent of infants with GER and 28 % of controls slept in an inclined position. Pediatricians repeated the prescription of dorsal decubitus for 91 % of infants with GER and recommended an inclined position in 70 %.

CONCLUSIONS

Regurgitations had no impact on supine sleeping position. The inclined supine sleeping position was more frequent in infants with regurgitations with pediatricians' assent, which is not in agreement with evidence-based medicine.

Sudden infant death syndrome: exposure to cigarette smoke leads to hypomethylation upstream of the growth factor independent 1 (GFI1) gene promoter

PURPOSE

Smoking during pregnancy has long been known as an important risk factor for sudden infant death syndrome (SIDS). However, the precise relationship between the smoking behavior of the mother and SIDS still remains unclear. In this study, the influence of prenatal smoking exposure on the childrens' DNA methylation state of a CpG island located upstream of the promoter of the growth factor independent 1 (GFI1) gene was analyzed.

METHODS

Blood samples of well-defined SIDS cases with non-smoking mothers (n = 11), SIDS cases with smoking mothers during pregnancy (n = 11), and non-SIDS cases (n = 6) were obtained from a previous study and methylation states were determined by bisulfite sequencing.

RESULTS

Significant hypomethylation was observed in this CpG island in SIDS cases with cigarette smoke exposure compared to non-exposed cases. The strongest effect in this CpG island was observed for 49 CpG sites located within a transcription factor binding site. Coding for a transcriptional repressor, GFI1 plays an important role in various developmental processes. Alterations in the GFI1 expression might be linked to various conditions that are known to be associated with SIDS, such as dysregulated hematopoiesis and excessive inflammatory response.

CONCLUSION

Data obtained in this study show that analysis of methylation states in cases of sudden infant death syndrome might provide a further important piece of knowledge toward understanding SIDS, and should be investigated in further studies.

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.

Parent-infant bed-sharing behavior : Effects of feeding type and presence of father

An evolutionarily informed perspective on parent-infant sleep contact challenges recommendations regarding appropriate parent-infant sleep practices based on large epidemiological studies. In this study regularly bed-sharing parents and infants participated in an in-home video study of bed-sharing behavior. Ten formula-feeding and ten breast-feeding families were filmed for 3 nights (adjustment, dyadic, and triadic nights) for 8 hours per night. For breast-fed infants, mother-infant orientation, sleep position, frequency of feeding, arousal, and synchronous arousal were all consistent with previous sleep-lab studies of mother-infant bed-sharing behavior, but significant differences were found between formula and breast-fed infants. While breast-feeding mothers shared a bed with their infants in a characteristic manner that provided several safety benefits, formula-feeding mothers shared a bed in a more variable manner with consequences for infant safety. Paternal bed-sharing behavior introduced further variability. Epidemiological case-control studies examining bed-sharing risks and benefits do not normally control for behavioral variables that an evolutionary viewpoint would deem crucial. This study demonstrates how parental behavior affects the bed-sharing experience and indicates that cases and controls in epidemiological studies should be matched for behavioral, as well as sociodemographic, variables.

Management of paediatric GERD

Paediatric GERD is complicated to manage, as symptoms are diverse and often difficult to interpret. In infants, regurgitation is a common physiological condition. Nevertheless, when it occurs frequently (>4 times per day) and causes the infant distress, parents often seek medical help. In children 2-10 years of age, GERD is often considered to cause extra-oesophageal symptoms, despite the absence of hard evidence. Diagnostic investigations often lack solid validation and the signs and symptoms of GERD overlap with those of cow's milk protein allergy and eosinophillic oesophagitis. Reassurance, dietary treatment and positional adaptations are recommended for troublesome infant reflux. Anti-acid medication, mainly PPIs, is over-used in infants even though, in many children, reflux is not an acid-related condition. Moreover, evidence is increasing that PPIs cause adverse events such as gastroenteritis and respiratory tract infections. Management in children older than 10 years is similar to that in adults. Using prokinetics to treat nonerosive reflux disease remains only a promising theoretical concept, as no such molecule is currently available. Today, the adverse effects of each prokinetic molecule largely outweigh its potential benefit. Laparoscopic surgery is indicated in children who have life-threatening symptoms or in cases of drug dependence.

Scientific consensus forum to review the evidence underpinning the recommendations of the Australian SIDS and Kids Safe Sleeping Health Promotion Programme--October 2010

This paper summarises a 1-day scientific consensus forum that reviewed the evidence underpinning the Australian SIDS and Kids Safe Sleeping Health Promotion Programme. The focus was on each of the potentially modifiable risk factors for sudden unexpected deaths in infancy, including sudden infant death syndrome (SIDS) and fatal sleeping accidents. In particular infant sleeping position, covering of the face, exposure to cigarette smoke, room sharing, unsafe sleeping environments, bed sharing, immunisation, breastfeeding, pacifier use and Indigenous issues were discussed in depth. The participants recommended that future 'Reducing the Risk' campaign messages should focus on back to sleep, face uncovered, avoidance of cigarette smoke before and after birth, safe sleeping environment, room sharing and sleeping baby in own cot.

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.

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.

Sudden infant death syndrome: how much mothers and health professionals know

BACKGROUND

Behavioral risk factors are associated with sudden infant death syndrome (SIDS). Education about the risk factors of SIDS is important for prevention. Our aim was to determine the knowledge and attitude of parents and health professionals about SIDS.

METHODS

A total of 174 health professionals and 150 mothers were enrolled in this study. Mothers' data were collected by telephone interview and health-care professionals were interviewed by the same investigator.

RESULTS

Only 39% of mothers were aware of SIDS. Forty-six percent of the mothers preferred a supine sleeping position for their infant and 16% of the parents were bed-sharing with their infants. Seventy-three percent of health professionals selected side, 17% supine and 10% prone sleeping position as the safest sleeping position. Frequencies for awareness of risk factors were: bed-sharing (75%), soft bedding (70%), pillow use (52%), toys in bed (90%), high room temperature (67%) and smoking (88%). Total knowledge score of health professionals who selected supine sleeping position as the safest was significantly higher (P < 0.001).

CONCLUSION

Most of the mothers were unaware of SIDS and less than half preferred a supine sleeping position for their infant. Only 72% of health professionals recommended a certain sleeping position during family interviews. Health professionals are more often recommending the side sleeping position or prone. Education of families and health professionals for the risk factors of SIDS may reduce the number of deaths from SIDS in Istanbul.

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.

SIDS: past, present and future

Despite the large reduction in SIDS mortality, which occurred in the early 1990s following the 'Back to Sleep' campaigns, SIDS remains the leading cause of death in the postneonatal age group. This paper describes the position in the 1980s, the contribution of the New Zealand Cot Death Study, what should be recommended and the current research priorities.

CONCLUSION

SIDS is preventable. Application of what we currently know could eliminate SIDS. The challenge is to find ways of implementing our knowledge.

Infant bed-sharing practices and associated risk factors among births and infant deaths in Alaska

OBJECTIVE

The Alaska Division of Public Health has stated that infants may safely share a bed for sleeping if this occurs with a nonsmoking, unimpaired caregiver on a standard, adult, non-water mattress. Because this policy is contrary to recent national recommendations that discourage any bed sharing, we examined 13 years of Alaskan infant deaths that occurred while bed sharing to assess the contribution of known risk factors.

METHODS

We examined vital records, medical records, autopsy reports, and first responder reports for 93% of Alaskan infant deaths that occurred between 1992 and 2004. We examined deaths while bed sharing for risk factors including sleeping with a non-caregiver, prone position, maternal tobacco use, impairment of a bed-sharing partner, and an unsafe sleep surface. We used Pregnancy Risk Assessment Monitoring System data to describe bed-sharing practices among all live births in Alaska during 1996-2003.

RESULTS

Thirteen percent (n=126) of deaths occurred while bed sharing; 99% of these had at least one associated risk factor, including maternal tobacco use (75%) and sleeping with an impaired person (43%). Frequent bed sharing was reported for 38% of Alaskan infants. Among these, 60% of mothers reported no risk factors; the remaining 40% reported substance use, smoking, high levels of alcohol use, or most often placing their infant prone for sleeping.

CONCLUSIONS

Almost all bed-sharing deaths occurred in association with other risk factors despite the finding that most women reporting frequent bed sharing had no risk factors; this suggests that bed sharing alone does not increase the risk of infant death.

Inner-city caregivers' perspectives on bed sharing with their infants

OBJECTIVE

To understand parents' motivations for bed sharing with their infants aged 1-6 months, their beliefs about safety concerns, and their attitudes about bed-sharing advice.

METHODS

We conducted 4 focus groups with primary caregivers of infants ages 1-6 months who regularly shared beds with their infants. We recruited participants from an inner-city primary care center in Pittsburgh, serving primarily African American families who received medical assistance. Discussions were audiotaped and transcribed. Two investigators coded the transcripts and identified themes in an iterative process to achieve agreement between coders.

RESULTS

A total of 28 caregivers aged 17-50 participated. The majority were African American (86%), female (93%), single (50%), and high school graduates (71%). Eleven percent of participants breast-fed their infants. We identified 5 themes, common to all groups, to explain parents' motivations for bed sharing: 1) better caregiver and infant sleep, 2) convenience, 3) tradition, 4) child safety, and 5) parent and child emotional needs. Parents expressed divergent views about the safety of bed sharing: 1) ambivalence regarding balancing risks of overlaying and suffocation with benefits of bed sharing, or 2) assertion that bed sharing poses no risks for their child. Common to all groups was the finding that clinicians' advice against bed sharing did not influence parents' decision, but advice to increase safety when bed sharing would be appreciated.

CONCLUSIONS

Parents' motivation to bed share outweighed the concerns and the warnings of others. An understanding of parents' perspectives on bed sharing should inform counseling to promote safe sleeping practices.

Current recommendations on infants' sleeping position are being followed-initial results of a population-based sentinel study on risk factors for SIDS, 1996-2006, in Hamburg, Germany

Sudden infant death syndrome (SIDS) is a target for public health care in Germany. The aim of this study was to monitor data on risk-related behavior in the population of Hamburg, Germany, in order to respond to changes quickly and to estimate the effectiveness of prevention activities. Data have been gathered using the sentinel system with repeated surveys (1996, 1998, 2001, and 2006) in pediatric practices, thus allowing an estimate of the prevalence of risk factors in an urban population, both transversally and vertically. From 1996 to 2007, the SIDS rate in Hamburg fell from 0.9/1,000 live births to 0.1. The prevalence of infants sleeping prone declined from 8.1% in 1996 to 3.5% in 2006. In this small subgroup, up to 81.7% (2006) of the caretakers were well aware of the risk of sleeping prone. The prevalence of infants sleeping on their sides fell from 55.3% in 1998 to 10.6% in 2006. The sentinel setting is suitable for gathering risk-related data on SIDS. Despite the fact that, so far, no nationwide back-to-sleep campaign has been instituted in Germany, local campaigns have proved successful in reducing prone sleeping for infants. Moreover, the substantial reduction of side sleeping within a short time span going along with a reduced SIDS rate is an indicator of the effectiveness of prevention activities on a local basis.

Infant sleep position, head shape concerns, and sleep positioning devices

AIM

The Back To Sleep campaign has successfully promoted the use of the supine sleep position for infants, with a corresponding decrease in sudden infant death syndrome death rates around the world. The aim of this study was to survey current infant sleep position practices, concerns about plagiocephaly, and the use of sleep positioning devices.

METHODS

A postal survey of 400 mothers of infants aged 6 weeks to 4 months was carried out in Auckland, New Zealand.

RESULTS

Of the 278 (69.5%) respondents, the supine position was usually used in 64.8%, the prone position in 2.9%, with 32.3% using the side position or a combination of side and back positions. Approximately one-third had a concern about their infant's head shape, and 80% described practices to help prevent head deformation. Thirty per cent reported they had changed their infant's sleep position because of head shape concerns. A third of the mothers used some sort of positioning system to maintain the infant's sleep position.

CONCLUSIONS

Anxieties about plagiocephaly, aspiration of vomit, and poor quality sleep are the main concerns that parents have about sleeping their infants on their backs. Further education is needed to inform mothers about these issues and to alleviate their fears.

Recommendations for sudden infant death syndrome prevention: a discussion document

This article reviews the evidence for the current UK Department of Health recommendations for prevention of sudden infant death syndrome (SIDS) and suggests other factors that should be considered. The wording of the Department of Health recommendations for SIDS prevention has changed over the past 6 years, but the specific recommendations are largely consistent with the scientific evidence. The emphasis on thermal and illness factors and immunisation could be reduced. Bed sharing and sharing the parental bedroom should be given more emphasis. Two major recommendations need to be discussed in greater detail: (1) breast feeding and (2) pacifier use. Meta-analyses or reviews looking at each risk factor or a combination of risk factors are required. Further, it is recommended that a committee is established that reviews the recommendations and publishes the evidence that leads to these recommendations, as is done by the American Academy of Pediatrics Taskforce on Sudden Infant Death Syndrome.

Sudden Infant Death Syndrome and the time of death: factors associated with night-time and day-time deaths

OBJECTIVE

To investigate the diurnal occurrence of Sudden Infant Death Syndrome (SIDS) and interaction with established risk factors in the infant sleeping environment.

METHODS

A 3 year population-based case-control study, in five English Health Regions. Parentally defined day-time or night-time deaths of 325 SIDS infants and reference sleep of 1300 age-matched controls.

RESULTS

The majority of SIDS deaths (83%) occurred during night-time sleep, although this was often after midnight and at least four SIDS deaths occurred during every hour of the day. The length of time from last observed alive until the discovery of death ranged from <l to 14 h but was not significantly different from the corresponding sleep period amongst the controls. Amongst the day-time deaths, 38% of the infants were observed alive 30 min prior to discovery and 9% within 10 min. The risk of placing infants asleep on their side was more marked for day-time deaths (interaction: P = 0.0001) nearly half of whom were found prone, while the risk associated with paternal smoking [OR = 3.25 (95%CI: 1.88-5.62)] was more marked for night-time deaths (interaction: P = 0.02). The adverse effect of unsupervised sleep recognized for night-time practice [OR = 5.38 (95%CI: 2.67-10.85)] was also significant for day-time sleep [OR = 10.57 (95%CI: 1.47-75.96)]. Significantly more (P = 0.002) unobserved SIDS infants (24.8%) were found with bedclothes over the head compared with those SIDS infants where a parent was present in the room (11.3%).

CONCLUSIONS

SIDS can happen at any time of the day and relatively quickly. Parents need to be made aware that placing infants supine and keeping them under supervision is equally important for day-time sleeps.

Co-sleeping, an ancient practice: issues of the past and present, and possibilities for the future

Co-sleeping-infants sharing the mother's sleep space-has prevailed throughout human evolution, and continued over the centuries of western civilization despite controversy and blame of co-sleeping mothers for the deaths of their infants. By the past century, "crib death" was recognized, later identified as Sudden Infant Death Syndrome (SIDS), and generally found to occur more frequently during bed sharing. Pediatricians warned parents of the dangers of SIDS and other risks of bed sharing, and the frequency of bed sharing decreased markedly over the years. However, during recent decades, bed sharing began to increase, though major issues were raised, including: whether bed sharing actually exacerbates or is protective against the occurrence of SIDS, whether the practice facilitates breast feeding, whether bed sharing is beneficial for an infant's development, and other concerns. Dissention may soon be diminished by use of a crib which opens at the mother's bed-side and is becoming a popular approach to mother-and-infant closeness through the night.

Sleep environment, positional, lifestyle, and demographic characteristics associated with bed sharing in sudden infant death syndrome cases: a population-based study

BACKGROUND

In 2005, the American Academy of Pediatrics Task Force on Sudden Infant Death Syndrome recommended that infants not bed share during sleep.

OBJECTIVE

Our goal was to characterize the profile of risk factors associated with bed sharing in sudden infant death syndrome cases.

DESIGN/METHODS

We conducted a population-based retrospective review of sudden infant death syndrome cases in New Jersey (1996-2000) dichotomized by bed-sharing status and compared demographic, lifestyle, bedding-environment, and sleep-position status.

RESULTS

Bed-sharing status was reported in 239 of 251 cases, with sharing in 39%. Bed-sharing cases had a higher percentage of bedding risks (44.1% vs 24.7%), exposure to bedding risks in infants discovered prone (57.1% vs 28.2%), and lateral sleep placement (28.9% vs 17.8%). The prone position was more common for bed-sharing and non-bed-sharing cases at placement (45.8% and 51.1%, respectively) and discovery (59.0% and 64.4%, respectively). In multivariable logistic-regression analyses, black race, mother <19 years, gravida >2, and maternal smoking were associated with bed sharing. There was a trend toward less breastfeeding in bed-sharing cases (22% vs 35%). In bed-sharing cases, those breastfed were younger than those who were not and somewhat more exposed to bedding risks (64.7% vs 45.1%) but less likely to be placed prone (11.8% vs 52.9%) or have maternal smoking (33% vs 66%).

CONCLUSIONS

Bed-sharing cases were more likely to have had bedding-environment and sleep-position risks and higher ratios of demographic and lifestyle risk factors. Bed-sharing subjects who breastfed had a risk profile distinct from those who were not breastfed cases. Risk and situational profiles can be used to identify families in greater need of early guidance and to prepare educational content to promote safe sleep.

Association Between Sudden Death in Infancy and Co-Sleeping

Our retrospective case review from 1978-2002, of infant deaths autopsied under the auspices of the Galveston County Medical Examiner Office, demonstrated a lack of detailed scene investigation, including sleeping circumstances and arrangements, as well as a pattern of ascribing the cause of death to SIDS even when there is evidence of a hazardous sleeping arrangement. During this period, 89/103 pediatric deaths were certified as SIDS and 39/103 of these were co-sleeping, 51/103 were sleeping alone, and 17/103 had no sleeping arrangement indicated. Upon review, there were only 6 cases where the scene visitation was documented. Only 9 cases used an Infant Death Investigation Form (IDIF), and this only started in 1999. The IDIF contains questions regarding the infants' sleep environment (bedding descriptions, co-sleeping, sleep surface) not used in the standard medical examiner death investigative forms. There has been an upward trend since the late 1990s in the number of scenes visited and detailed descriptions of the scenes, likely due to the increased awareness of hazardous infant sleeping conditions identified by American Academy of Pediatrics and U.S. Consumer Product Safety Commission. The association between co-sleeping and sudden infant death remains controversial among clinicians. We report a high association between these two conditions.

Case-control study of sudden infant death syndrome in Lithuania, 1997-2000

BACKGROUND

To identify risk factors for sudden infant death syndrome relevant in Lithuania.

METHODS

A nationwide case-control study surveying parents of 35 infants who died from sudden infant death syndrome during the period of 1997-2000 and parents of 145 control infants matched with SIDS infants for date of birth and for region of birth was carried out.

RESULTS

Deaths incidence was greater in the warm period (60%) vs. cold period (40%). Prone and side sleeping positions both carried no increased risk of sudden infant death syndrome compared with supine because of a rare prone sleeping (4.1% of controls vs. 0% of dead infants) and more prevalent side than supine sleeping (84.8% of controls vs. 94.3% of dead infants) in the controls as well as the cases. Bed sharing for the whole night as a risk factor for sudden infant death syndrome has not been confirmed, either, as bed sharing was common only for the controls (13.8% of controls vs. 0% of dead infants). Routine sleeping environment factors such as heavy wrapping (> or =4 togs) of an infant (odds ratio 8.49; 95% confidence interval 2.38 to 30.32), sleeping in a bassinet (4.22; 1.16 to 15.38) and maternal factors such as maternal education < or =12 years (4.48; 1.34 to 14.94), unplanned pregnancy (5.22; 1.49 to 18.18) and > or =2 previous live births (3.90; 1.00 to 15.10) were significantly associated with sudden infant death syndrome on multivariate analysis.

CONCLUSION

The results of this first population-based case-control study have shed some light on the epidemiology of the syndrome in Lithuania. Although the mortality of sudden infant death syndrome in Lithuania is not high, it might be lowered moreover by public informing about sudden infant death syndrome and related risk factors. Special attention must be paid to mothers with low education on potentially modifiable risk factors such as routine heavy wrapping of an infant during sleep, routine sleeping in a bassinet and unplanned pregnancy.

Risk factors associated with sudden unexplained infant death: a prospective study of infant care practices in Kentucky

OBJECTIVE

To ascertain the prevalence of infant care practices in a metropolitan community in the United States with attention to feeding routines and modifiable risk factors associated with sudden unexplained infant death (specifically, prone sleeping position, bed sharing, and maternal smoking).

METHODS

We conducted an initial face-to-face meeting followed by a telephone survey of 189 women who gave birth at a level I hospital in Kentucky between October 14 and November 10, 2002, and whose infants were placed in the well-infant nursery. The survey, composed of questions pertaining to infant care practices, was addressed to the women at 1 and 6 months postpartum.

RESULTS

A total of 185 (93.9%) women participated in the survey at 1 month, and 147 (75.1%) mothers contributed at 6 months. The racial/ethnic composition of the study was 56.1% white, 30.2% black, and 16.4% biracial, Asian, or Hispanic. More than half of the infants (50.8%) shared the same bed with their mother at 1 month, which dramatically decreased to 17.7% at 6 months. Bed sharing was significantly more common among black families compared with white families at both 1 month (adjusted odds ratio [OR]: 5.94; 95% confidence interval [CI]: 2.71-13.02) and 6 months (adjusted OR: 5.43; 95% CI: 2.05-14.35). Compared with other races, white parents were more likely to place their infants on their back before sleep at both 1 and 6 months. Black parents were significantly less likely to place their infants on their back at 6 months compared with white parents (adjusted OR: 0.14; 95% CI: 0.06-0.33). One infant succumbed to sudden infant death syndrome at 3 months of age, and another infant died suddenly and unexpectedly at 9 months of age. Both were bed sharing specifically with 1 adult in the former and with 2 children in the latter.

CONCLUSIONS

Bed sharing and prone placement were more common among black infants. Breastfeeding was infrequent in all races. This prospective study additionally offers a unique perspective into the risk factors associated with sudden infant death syndrome and sudden unexplained infant death associated with bed sharing by examining the survey responses of 2 mothers before the death of their infants combined with a complete postmortem examination, scene analysis, and historical investigation.

Modifiable risk factors for SIDS in Germany: results of GeSID

BACKGROUND

The incidence of sudden infant death syndrome (SIDS) has been falling in Germany over the last decade. However, little is known about the prevalence and the importance of well-known risk factors in Germany since a local prevention campaign in 1992.

DESIGN

A 3-y, population-based, case-control study was conducted in half of Germany, consisting of 333 cases. All sudden and unexpected deaths in infancy, if they fitted the inclusion criteria, were included in the study. Parental interview was carried out soon after the death, and three living control infants, matched for age, gender, region and sleep time, were recruited.

RESULTS

The prevalence of placing infants prone to sleep was only 4% in the control group, but this was associated with a markedly increased risk of SIDS (adjusted odds ration, aOR=6.08). Other modifiable risk factors for SIDS were: maternal smoking during pregnancy, breastfeeding for less than 2 wk (aOR=1.71) and co-sleeping (aOR=2.71), while using a pacifier during the last sleep reduced the risk (aOR=0.39).

CONCLUSIONS

Previously recognized risk factors for SIDS also occur in Germany. Despite knowledge about the major modifiable risk factors for SIDS, these factors are still present in Germany. To reduce the incidence of SIDS in Germany, a continued effort is needed to inform all parents about preventable risk factors for SIDS.

Cosleeping and Sudden Unexpected Infant Deaths in Kentucky

This retrospective case review investigates modifiable risk factors in sudden unexpected infant deaths, including those attributed to sudden infant death syndrome, and examines the impact of cosleeping with adults or siblings. The study examines sudden unexpected infant deaths from 1991 to 2000 in the state of Kentucky, excluding homicides and deaths from identifiable natural causes. Meta-analysis provides a cosleeping prevalence control in normal infants. Based on the findings described herein, we conclude that cosleeping may represent a risk factor in sudden unexpected infant deaths and that a full scene investigation, including whether the infant was cosleeping, should be sought in all cases of sudden infant death.

Sudden infant death syndrome and unclassified sudden infant deaths: a definitional and diagnostic approach

The definition of sudden infant death syndrome (SIDS) originally appeared in 1969 and was modified 2 decades later. During the following 15 years, an enormous amount of additional information has emerged, justifying additional refinement of the definition of SIDS to incorporate epidemiologic features, risk factors, pathologic features, and ancillary test findings. An expert panel of pediatric and forensic pathologists and pediatricians considered these issues and developed a new general definition of SIDS for administrative and vital statistics purposes. The new definition was then stratified to facilitate research into sudden infant death. Another category, defined as unclassified sudden infant deaths, was introduced for cases that do not meet the criteria for a diagnosis of SIDS and for which alternative diagnoses of natural or unnatural conditions were equivocal. It is anticipated that these new definitions will be modified in the future to accommodate new understanding of SIDS and sudden infant death.

Frequency of bed sharing and its relationship to breastfeeding

Bed sharing has been promoted as facilitating breastfeeding but also may increase risks for sudden, unexpected infant deaths. This prospective cohort study was performed to determine the prevalence of adult and infant bed sharing and its association with maternal and infant characteristics. Demographic data were collected from 10,355 infant-mother pairs at birth hospitals in Eastern Massachusetts and Northwest Ohio, and follow-up data were collected at 1, 3, and 6 months by questionnaire. Associations with bed sharing were estimated using odds ratios and 95% confidence intervals from multiple logistic regression models while adjusting for confounding variables. At 1, 3, and 6 months, 22%, 14%, and 13% of infant-mother pairs shared a bed, respectively. On multivariate analysis, race/ethnicity and breastfeeding seemed to have the strongest association with bed sharing. These factors need to be considered in any comprehensive risk to benefit analysis of bed sharing.

Sudden unexpected deaths after discharge from the neonatal intensive care unit

The published evidence on the risk of sudden unexpected death in infants after discharge from the neonatal intensive care unit (NICU) is reviewed, together with the relevance of the various identified potentially modifiable post-natal risk factors, particularly sleeping position. Infants of low birthweight, short gestation, and those with adverse perinatal histories are at substantially increased risk of sudden infant death syndrome (SIDS), but the potential benefits from following the measures designed to reduce the risk of SIDS are proportionally greater than for term infants. The use of home apnoea monitors has not been shown to be of value in preventing SIDS, but the importance of maintaining adequate oxygenation in infants with bronchopulmonary dysplasia is emphasised. Evidence based recommendations for care of infants after discharge from the NICU with a view to reducing the risk of SIDS are presented, and do not differ significantly from those for low-risk infants.

Infant Sleep Positioning by Nursery Staff and Mothers in Newborn Hospital Nurseries

BACKGROUND

Although advice from healthcare professionals may influence parental infant placement choice to reduce sudden infant death syndrome risk, literature on nursery staff infant placement behaviors and the degree to which they influence maternal infant sleep positioning is limited.

OBJECTIVE

To assess newborn placement practices of the mother and nursery staff and their interrelationship in the hospital setting.

METHODS

A cross-sectional survey-based study was conducted among hospital newborn nursery staff (n = 96) and mothers of newborns (n = 579) at eight perinatal hospitals in Orange County, California.

RESULTS

Although a majority of sampled nursery staff (72%) identified the supine position as the placement that most lowers sudden infant death syndrome risk, only 30% reported most often placing infants to sleep in that position, with most staff (91%) citing fear of aspiration as the motivation for supine position avoidance. Only 34% of staff reported advising exclusive supine infant positioning to mothers. Approximately 36% of mothers reported using supine infant placement exclusively. Maternal infant placement choice varied by both the advice (p <.01) and the placement modeling (p <.01) provided by staff, with the highest proportion of usual supine infant placement found among mothers who reported receiving both. A mother's race/ethnicity also affected the reception of exclusive supine placement recommendations (p <.01).

CONCLUSIONS

Exclusive supine infant placement appears to be underused by both nursery staff and mothers of newborn infants. Culturally grounded educational intervention with nursery staff regarding infant positioning and placement in the hospital setting is indicated.

Infant sleep position: associated maternal and infant factors

OBJECTIVE

To determine the maternal and infant characteristics associated with the back sleep position for infants to guide efforts to increase its use and reduce the risk of Sudden Infant Death Syndrome.

METHODS

Cross-sectional survey of 3349 mothers delivering in California, February-May 1999.

RESULTS

Fifty-two percent of infants were placed in the back sleep position. Factors associated with a lower likelihood of using the back position included all levels of maternal education less than college (eg, for education eighth grade or less--adjusted odds ratio [OR] 0.59; 95% confidence interval [CI], 0.40-0.86); income at or below federal poverty level (OR, 0.65; 95% CI, 0.47-0.90); multiparity (OR, 0.80; 95% CI, 0.67-0.95); race/ethnicity African American (OR, 0.49; 95% CI, 0.37-0.65) and Asian/Pacific Islander (OR, 0.65; 95% CI, 0.48-0.89); speaking a non-English language (OR, 0.69; 95% CI, 0.55, 0.86); and infant age over 7 months (OR, 0.70, 95% CI, 0.52-0.96). Women in Los Angeles (OR, 0.57; 95% CI, 0.42-0.77) and urban areas other than San Diego (OR, 0.70; 95% CI, 0.53-0.92) were less likely to use the back position than those in San Francisco.

CONCLUSIONS

Greater efforts are needed to promote the back sleep position among families with mothers who lack education beyond some college; live in poverty; and who are African American, Asian/Pacific Islander, multiparous, or non-English speaking.

Sudden infant death syndrome: overview and update

The past decade and a half has seen marked changes in the epidemiology of sudden infant death syndrome (SIDS). The avoidance of certain risk factors such as sleeping prone and cigarette smoke exposure has resulted in the death rate falling dramatically. Careful evaluation of environmental factors and endogenous characteristics has led to a greater understanding of the complexities of the syndrome. The development and implementation of death scene and autopsy protocols has led to standardization in approaches to unexpected infant deaths with increasing diagnoses of accidental asphyxia. Despite these advances, there is still confusion surrounding the diagnosis, with deaths being attributed to SIDS in many communities and countries where death scene investigations and autopsies have not been conducted. The following review provides a brief overview of the historical background, epidemiology, pathology, and pathogenesis of SIDS. Contentious issues concerning the diagnosis and current problems are discussed. Despite calls to abandon the designation, SIDS remains a viable term for infants who die in their sleep with no evidence of accident, inflicted injury, or organic disease after a full investigation has been conducted according to standard guidelines.

Racial disparity and modifiable risk factors among infants dying suddenly and unexpectedly

BACKGROUND

Racial disparity in rates of death attributable to sudden infant death syndrome (SIDS) has been observed for many years. Despite decreased SIDS death rates following the "Back to Sleep" intervention in 1994, this disparity in death rates has increased. The prone sleep position, unsafe sleep surfaces, and sharing a sleep surface with others (bedsharing) increase the risk of sudden infant death. The race-specific prevalence of these modifiable risk factors in sudden unexpected infant deaths-including SIDS, accidental suffocation (AS), and cause of death undetermined (UD)-has not been investigated in a population-based study. Death rates attributable to AS and UD are also higher in African Americans (AAs) than in other races (non-AA). The potential contribution of unsafe sleep practices to this overall disparity in death rates is uncertain.

OBJECTIVE

The objective of this study was to compare death rates attributable to SIDS and related causes of death (AS and UD) in AA and non-AA infants and the prevalence of unsafe sleep practices at time of death. Our hypothesis was that there is a large racial disparity in these modifiable risk factors at the time of death, and that public awareness of this could lead to improved intervention strategies to reduce the disparity in death rates.

METHODS

In this population-based study, we retrospectively reviewed death-scene information and medical examiners' investigations of deaths in St Louis City and County between January 1, 1994, and December 31, 1997. The deaths of all infants <2 years old with the diagnoses of SIDS, AS, or UD were included. Sleep surfaces other than those specifically designed and approved for infant use were termed nonstandard (adult beds, sofas, etc). Denominators for our rate estimates were the number of births (AA and non-AA) in St Louis City and County during the study period.

RESULTS

The deaths of 119 infants were studied (81 AA and 38 non-AA). SIDS rates were much higher in AA than non-AA infants (2.08 vs 0.65 per 1000 live births), as was the rate of AS (0.47 vs 0.06). There was a trend for increased deaths diagnosed as UD in AA infants (0.36 vs 0.06). Bedsharing deaths were nearly twice as common in AAs (67.1% vs 35.1% of deaths), as were deaths on nonstandard sleep surfaces (79.0% vs 46.0%). Forty-nine percent (49.1%) of all infants who died while bedsharing were found on their backs or sides compared with 20.4% of infants who were not bedsharing. Overall, the fraction of infants found in these nonprone positions was not different for AA infants and non-AA infants (43.3% vs 38.5%). In AA and non-AA infants, factors that greatly increase the risk of bedsharing, such as sofa sharing or all-night bedsharing, were present in all or many bedsharing deaths.

CONCLUSION

Among AA infants dying suddenly and unexpectedly, the high prevalence of nonstandard bed use and bedsharing may underlie, in part, their increased death rates. Public health messages tailored for the AA community have stressed first and foremost using nonprone sleep positions. The observation that there was no difference between AA and non-AA infants in position found at death suggests that racial disparity in sleep position is not the most important contributor to racial disparity in death rates. The finding that more infants died on their back or side while bedsharing than otherwise suggests that these sleep positions are less protective when associated with bedsharing. We conclude that public health information tailored for the AA community should give equal emphasis to risks and alternatives to bedsharing as to avoidance of the prone position.

Secular changes in sleep position during infancy: 1995-1998

OBJECTIVE

Prone sleeping among infants has been associated with an increased risk of sudden infant death syndrome. The objective of this study was to compare factors associated with sleep position in 1995-1996 and 1997-1998 and to assess secular trends in use of prone infant sleep position from 1995 through 1998 among families stratified by race and education.

METHODS

A prospective cohort study was conducted in eastern Massachusetts and northwest Ohio of 12 029 mothers of infants who weighed > or =2500 g at birth. Descriptive statistics and multivariate odds ratios were used to relate maternal and infant characteristics to prone and supine sleeping.

RESULTS

A total of 14 206 mothers (25% of those eligible) were enrolled. A total of 12 029 mothers (85% of enrolled) responded to the 1-month and 11 552 mothers (81% of enrolled) responded to the 3-month follow-up questionnaire. A decline in use of the prone sleep position and increase in use of the supine position was observed during the 4 years of the study. Factors associated with prone and supine sleep position were similar in 1995-1996 and 1997-1998. In 1997-1998, use of prone sleeping at 1 month of age reached the goal of < or =10% only among infants of white and Asian women, married women, women who were older than 25 years, women who were college graduates, and women with incomes >$55 000 per year. At 3 months of age, however, prone sleeping increased to 12% to 17% in these groups. These same groups were most likely to use the supine position; 38% to 45% were supine at 1 month, increasing to 56% to 64% by 3 months of age. However, as of the end of 1998, approximately 27% of infants of non-college-educated black and Hispanic mothers were placed to sleep in the prone position and only 20% to 30% were being placed to sleep in the supine position at 3 months of age.

CONCLUSIONS

Recommendations to avoid prone sleep position and especially the recommendation that supine sleep position is preferred have not been effectively delivered to black and Hispanic families and to families of low-income and less than a college education.

The contribution of prone sleeping position to the racial disparity in sudden infant death syndrome: the Chicago Infant Mortality Study

BACKGROUND

Rates of sudden infant death syndrome (SIDS) are over twice as high among African Americans compared with Caucasians. Little is known, however, about the relationship between prone sleeping, other sleep environment factors, and the risk of SIDS in the United States and how differences in risk factors may account for disparities in mortality.

OBJECTIVE

To assess the contribution of prone sleeping position and other potential risk factors to SIDS risk in a primarily high-risk, urban African American population.

DESIGN, SETTING, AND POPULATION

Case-control study consisting of 260 infants ages birth to 1 year who died of SIDS between November 1993 and April 1996. The control group consists of an equal number of infants matched on race, age, and birth weight. Prospectively collected data from the death scene investigation and a follow-up home interview for case infants were compared with equivalent questions for living control participants to identify risk factors for SIDS.

MAIN OUTCOME MEASURES

Risk of SIDS related to prone sleeping position adjusting for potential confounding variables and other risk factors for SIDS, and comparisons by race-ethnicity.

RESULTS

Three quarters of the SIDS infants were African American. There was more than a twofold increased risk of SIDS associated with being placed prone for last sleep compared with the nonprone positions (odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.6-3.7). This OR increased after adjusting for potential confounding variables and other sleep environment factors (OR: 4.0; 95% CI: 1.8-8.8). Differences were found for African Americans compared with others (OR: 1.8; 95% CI: 1.2-2.6 and OR: 10.3, 95% CI: 10.3 [3.2-33.8, respectively]). The population attributable risk was 31%. Fewer case mothers (46%) than control mothers (64%) reported being advised about sleep position in the hospital after delivery. Of those advised, a similar proportion of case mothers as control mothers were incorrectly told or recalled being told to use the prone position, but prone was recommended in a higher proportion of black mothers (cases and controls combined) compared with nonblack mothers.

CONCLUSIONS

Prone sleeping was found to be a significant risk factor for SIDS in this primarily African American urban sample, and approximately one third of the SIDS deaths could be attributed to this factor. Greater and more effective educational outreach must be extended to African American families and the health personnel serving them to reduce prone prevalence during sleep, which appears, in part, to contribute to the higher rates of SIDS among African American infants.

Outcome correlates of parent-child bedsharing: an eighteen-year longitudinal study

We report results of the first longitudinal study of outcome correlates of parent-child bedsharing. Two hundred five families in nonconventional and conventional family lifestyles have been followed since 1975. A target child in each family was followed from the third trimester of mother's pregnancy through age 18 years. Bedsharing in early childhood was found to be significantly associated with increased cognitive competence measured at age 6 years, but the effect size was small. At age 6 years, bedsharing in infancy and early childhood was not associated with sleep problems, sexual pathology, or any other problematic consequences. At age 18 years, bedsharing in infancy and childhood was unrelated to pathology or problematic consequences, nor was it related to beneficial consequences. We discuss these results in light of widespread fears of harm caused by parent-child bedsharing. We suggest that such fears are without warrant if bedsharing is practiced safely as part of a complex of valued and related family practices.

Population trends in sudden infant death syndrome

This review documents and assesses recent trends in sudden infant death syndrome. We review medical literature, Internet resources, and national governmental data. A striking reduction in SIDS incidence of more than 50% has been observed in various countries after interventions, particularly during the early 1990s, to reduce the prevalence of prone infant sleeping. A reduction in postneonatal mortality has accompanied these lower rates. Evaluation studies from several countries indicate that the SIDS rate drop is largely attributable to a decline in the proportion of babies sleeping prone. Within countries, the SIDS rate decline has not occurred to the same extent for different ethnic and socio-economic groups. Future public health activities must aim to address this issue. In the post-intervention era, the relative importance of the risk factors of side compared to supine sleeping and soft bedding near the infant's airway have become more evident. Recent death scene data indicate that a substantial proportion of the remaining SIDS deaths could be avoided by supine sleeping and by providing a safe sleeping environment for all infants.

Sudden infant death syndrome risk factors in north Queensland: a survey of infant-care practices in Indigenous and non-Indigenous women

OBJECTIVE

To assess the prevalence of sudden infant death syndrome (SIDS) risk factors in the Indigenous and non-Indigenous community of Townsville, a large remote urban centre in north Queensland, Australia.

METHODS

Thirty Indigenous and 30 non-Indigenous women with young children were surveyed using sections of the West Australian Infancy and Pregnancy Survey 1997-1998. The prevalence of SIDS risk factors was compared between the two groups and medians and univariate associations were generated where appropriate.

RESULTS

The Indigenous women were significantly younger and more likely to be single. The median age of the infants was 8 months (range 0.3-26 months) with no difference between the two groups. Thirty-seven per cent of Indigenous infants slept prone (cf. 17% of non-Indigenous infants; P = 0.03), and 77% shared a bed (cf. 13% of non-Indigenous infants; P < 0.001). The Indigenous households had significantly more members, with 57% including extended family members (cf. 20% non-Indigenous group; P = 0.003). Fifty-three per cent of the Indigenous women smoked during pregnancy (cf. 23% of non-Indigenous women; P = 0.017), 60% were smokers at the time of the interview, and smoking occurred inside 40% of Indigenous houses (cf. 20% and 20% for non-Indigenous women, respectively; P < 0.001, 0.09).

CONCLUSION

This small survey suggests that the prevalence of SIDS risk factors is higher in the Indigenous population, and a new approach to education is needed urgently to promote SIDS awareness among Indigenous women.