SIDS: past, present and future

Effect of sleeping position on cardiac output, pulmonary pressure, and superior vena cava flow in healthy term infants

BACKGROUND

Although the mechanism of action in newborns is unknown, sleep positioning is associated with many pathophysiological events. This study aimed to compare the effects of supine and prone sleeping positions on cardiac output (CO), systolic pulmonary arterial pressure (SPAP), and superior vena cava (SVC) flow in healthy newborns.

METHODS

In the first 24-72 h of life, 40 healthy term newborns born in the same hospital were included in this prospective, cross-sectional, observational study. CO, SVC flow, and SPAP values of newborns in the supine and prone sleeping positions were calculated using echocardiographic examination. The measurements were statistically compared.

RESULTS

In the supine sleeping position, CO, SVC flow, and SPAP were 235.00 (193.07-283.30) ml/kg/min, 92.80 (77.82-121.87) ml/kg/min, and 27.85 (24.70-30.48) mmHg. In the prone sleeping position, CO, SVC flow, and SPAP were measured as 195.35 (166.00-229.40) ml/kg/min, 67.25 (51.82-96.66) ml/kg/min, 31.60 (28.45-37.20) mmHg, respectively. Depending on sleeping position, these variables were significantly different between the groups.

CONCLUSION

SVC flow and CO decreased in the prone sleeping position compared to the supine sleeping position in healthy newborns, whereas SPAP increased. The different hemodynamic effects of sleeping position on the cardiac, pulmonary, and nervous systems should be considered as flow and pressure changes are important in newborns.

Holistic antenatal education class interventions: a systematic review of the prioritisation and involvement of Indigenous Peoples' of Aotearoa New Zealand, Australia, Canada and the United States over a 10-year period 2008 to 2018

BACKGROUND

Research into the effectiveness of antenatal education classes is crucial for Indigenous Peoples from Aotearoa New Zealand, Australia, Canada and the United States who experience poorer maternal and infant health outcomes compared to non-Indigenous populations. Our systematic review questions were intended to determine the extent of Indigenous Peoples prioritisation and involvement in antenatal education classes, and to understand the experience of Indigenous Peoples from these countries in antenatal education classes.

METHODS

Using a standardised protocol, we systematically searched five electronic databases for primary research papers on antenatal education classes within the four countries noted and identified 17 papers that met the criteria. We undertook a qualitative meta-synthesis using a socio-critical lens.

RESULTS

Systematic review of the academic literature demonstrates that Indigenous Peoples of Aotearoa New Zealand, Australia, Canada and the United States are not prioritised in antenatal education classes with only two of 17 studies identifying Indigenous participants. Within these two studies, Indigenous Peoples were underrepresented. As a result of poor engagement and low participation numbers of Indigenous Peoples in these antenatal education classes, it was not possible to understand the experiences of Indigenous Peoples.

CONCLUSION

Given that Indigenous Peoples were absent from the majority of studies examined in this review, it is clear little consideration is afforded to the antenatal health needs and aspirations of Indigenous Peoples of Aotearoa New Zealand, Australia, Canada and the United States. To address the stark antenatal health inequities of Indigenous Peoples, targeted Indigenous interventions that consider culture, language, and wider aspects of holistic health must be privileged.

TRIAL REGISTRATION

PROSPERO Registration ID: CRD4202017658.

Risk and Preventive Factors for SUDI: Need We Adjust the Current Prevention Advice in a Low-Incidence Country

Background: The incidence of Sudden Unexpected Death in Infancy (SUDI) is low in the Netherlands, with an incidence rate of 0.18 per 1,000 live births. Therefore, prevention advice may receive less attention, potentially leading to increasing incidence rates. It is currently unknown whether the risks for SUDI changed in the Netherlands, and if other risk factors might be present. The aim of this study was to examine the current risks and preventive factors for SUDI in Dutch infants, in order to determine if it is necessary to adapt the prevention advice toward the current needs. Methods: A case-control study was conducted comparing SUDI cases aged <12 months from 2014-2020 in the Netherlands (n = 47), to a Dutch national survey control group from 2017 including infants <12 months of age (n = 1,192). Results: Elevated risks for several well-known factors were observed, namely: duvet use (aOR = 8.6), mother smoked during pregnancy (aOR = 9.7), or after pregnancy (aOR = 5.4) and the prone sleeping position (aOR = 4.6). Reduced risks were observed for the well-known factors: room-sharing (aOR = 0.3), sleep sack use (aOR = 0.3), breastfeeding (aOR = 0.3), and the use of a pacifier (aOR = 0.4). For infants <4 months, the risk for SUDI was higher when bed-sharing (aOR = 3.3), and lower when room-sharing (aOR = 0.2) compared to older infants. For older infants, the sleep sack was found to be more protective (aOR = 0.2). A high risk for SUDI when bed-sharing was found when mother smoked, smoked during pregnancy, or if the infant did not receive any breastfeeding (respectively aOR = 17.7, aOR = 10.8, aOR = 9.2). Conclusions: Internationally known factors related to the sudden unexpected death of infants were also found in this study. Relatively new findings are related to specific groups of infants, in which the strengths of these risk factors differed. In a low-incidence country like the Netherlands, renewed attention to the current prevention advice is needed. Furthermore, additional attention for prevention measures in low educated groups, and additional advice specifically targeting high-risk groups is recommended.

Sudden infant death syndrome: Melatonin, serotonin, and CD34 factor as possible diagnostic markers and prophylactic targets

Sudden infant death syndrome (SIDS) is one of the primary causes of death of infants in the first year of life. According to the WHO's data, the global infant mortality rate is 0.64-2 per 1,000 live-born children. Molecular and cellular aspects of SIDS development have not been identified so far. The purpose of this paper is to verify and analyze the expression of melatonin 1 and 2 receptors, serotonin (as a melatonin precursor), and CD34 molecules (as hematopoietic and endothelial markers of cardiovascular damage) in the medulla, heart, and aorta in infants who died from SIDS. An immunohistochemical method was used to investigate samples of medulla, heart, and aorta tissues of infants 3 to 9 months of age who died from SIDS. The control group included children who died from accidents. It has been shown that the expression of melatonin receptors as well as serotonin and CD34 angiogenesis markers in tissues of the medulla, heart, and aorta of infants who died from SIDS is statistically lower as compared with their expression in the same tissues in children who died from accidents. The obtained data help to clarify in detail the role of melatonin and such signaling molecules as serotonin and CD34 in SIDS pathogenesis, which can open new prospects for devising novel methods for predictive diagnosis of development and targeted prophylaxis of SIDS.

Evaluation of a Safe Sleep Training for Home Visitors and Their Clients

Sleep-related deaths are a common preventable cause of death, and such deaths occur disproportionately in families of color. Home visitors provide families with education about infant safe sleep guidelines; however, families face many barriers to engaging in safe sleep practices. This study evaluated the efficacy of a program to train home visitors to talk to clients about infant safe sleep using Motivational Interviewing and cultural sensitivity. We examined the effects of the intervention on home visitors' (n = 23) knowledge, MI skill use, and cultural sensitivity using a single group pre-post design. We also examined home visiting clients' (n = 78) knowledge, attitudes, and behaviors using a quasi-experimental design. Home visitors were primarily female (97%), had a college degree (86%), and were primarily white (50%) or African American (43%). The home visiting clients were all female and were primarily African American (43%) and Caucasian (36%). Most clients (59%) earned less than 30,000 dollars per year. Home visitors showed significant improvement in MI skill use and cultural sensitivity from pre- to post-test. Regarding client outcomes, our results indicate a significant group by time interaction when predicting changes in client knowledge such that the treatment group showed larger gains than the control group. There were no significant differences between groups when predicting changes in client attitudes or behavior. MI may be an effective technique for home visitors to help increase families' safe sleep knowledge. Additional research is needed to examine whether such training can translate to changes in families' safe sleep behavior.

Decreasing smoking during pregnancy: Potential economic benefit of reducing sudden unexpected infant death

Sudden Unexpected Infant Death (SUID) remains the leading cause of death among U.S. infants age 1-12 months. Extensive epidemiological evidence documents maternal prenatal cigarette smoking as a major risk factor for SUID, but leaves unclear whether quitting reduces risk. This Commentary draws attention to a report by Anderson et al. (Pediatrics. 2019, 143[4]) that represents a breakthrough on this question and uses their data on SUID risk reduction to delineate potential economic benefits. Using a five-year (2007-11) U.S. CDC Birth Cohort Linked Birth/Infant Death dataset, Anderson et al. demonstrated that compared to those who continued smoking, women who quit or reduced smoking by third trimester decreased the adjusted odds of SUID risk by 23% (95% CI, 13%-33%) and 12% (95% CI, 2%-21%), respectively. We applied these reductions to the U.S. Department of Health and Human Services' recommended value of a statistical life in 2020 ($10.1 million). Compared to continued smoking during pregnancy, the economic benefits per woman of quitting or reducing smoking are $4700 (95% CI $2700-$6800) and $2500 (95% CI, $400-$4300), respectively. While the U.S. obtained aggregate annual economic benefits of $0.58 (95% CI, 0.35-0.82) billion from pregnant women who quit or reduced smoking, it missed an additional $1.16 (95%CI 0.71-1.60) billion from the women who continued smoking. Delineating the health and economic impacts of decreasing smoking during pregnancy using large epidemiological studies like Anderson et al. is critically important for conducting meaningful economic analyses of the benefits-costs of developing more effective interventions for decreasing smoking during pregnancy.

Infant care practices and parent uptake of safe sleep messages: a cross-sectional survey in Queensland, Australia

Background

Globally, the incidence of sleep-related infant mortality declined dramatically following the first public health campaigns seen internationally in the 1990s to reduce the risks of sudden infant death. However, Australian Sudden Unexpected Death in Infancy (SUDI) rates have plateaued with little change in incidence since 2004 despite two further public health safe sleep campaigns. This study aims to describe contemporary infant care practices employed by families related to the current public health SUDI prevention program.

Methods

A cross-sectional survey of 3341 Queensland primary caregivers with infants approximately 3-months of age was conducted using the Queensland Registry of Births, Deaths and Marriages as a sampling frame. Surveys were returned either via reply-paid mail or online. Questionnaires explored prevalence of infant care practices and awareness of safe sleep recommendations. Univariable analysis was used to generate descriptive statistics for key variables.

Results

Overall, only 13% of families routinely practised all six ‘Safe Sleeping’ program messages. More than one third (1118, 34%) of infants had slept in a non-supine sleep position at some time. Potentially hazardous sleep environments were common, with 38% of infants sleeping with soft items or bulky bedding, or on soft surfaces. Nearly half, for either day- or night-time sleeps, were routinely placed in a sleep environment that was not designed or recommended for safe infant sleep (i.e. a bouncer, pram, beanbag). Most babies (84%) were reportedly smoke free before and after birth. Sleeping in the same room as their caregiver for night-time sleeps was usual practice for 75% of babies. Half (1600, 50%) of all babies shared a sleep surface in the last two-weeks. At 8-weeks, 17% of infants were no longer receiving any breastmilk.

Conclusions

The prevalence rates of infant care practices among this Australian population demonstrate many families continue to employ suboptimal practices despite Australia’s current safe sleep campaign. Strategic approaches together with informed decisions about pertinent messages to feature within future public health campaigns and government policies are required so targeted support can be provided to families with young infants to aid the translation of safe sleep evidence into safe sleeping practices.

Innovation to prevent sudden infant death: the wahakura as an Indigenous vision for a safe sleep environment

The bassinet-like wahakura is an Indigenous initiative for the prevention of Sudden Unexpected Death in Infancy (SUDI). It was developed by New Zealand Māori in 2005 when Māori were rejecting the 'stop bedsharing' SUDI prevention message and the SUDI disparity between Māori and non-Māori had become entrenched. Made of native flax, the wahakura was promoted as a culturally resonant, in-bed safe sleep device that would disrupt the SUDI risk associated with 'bedsharing where there was smoking in pregnancy' without relying on smoking cessation. A significant movement of weavers and health professionals grew around the wahakura program. A body of research, including infant care surveys, retrospective case review, qualitative enquiry and a randomised controlled trial comparing wahakura and bassinet safety demonstrated the device's public health plausibility, acceptability to Māori women and its essential safety. This facilitated the distribution, by District Health Boards, of safe sleep devices, including a related device called the Pēpi-Pod, and safe sleep education to high-risk, mainly Māori, mothers. Infant mortality in New Zealand fell by 29%, primarily among Māori infants, over the period 2009-15, suggesting that Māori cultural concepts, traditional activities and community engagement can have a significant effect on ethnic inequities in infant mortality.

Sudden Infant Death Syndrome and Safe Sleep on Twitter: Analysis of Influences and Themes to Guide Health Promotion Efforts

BACKGROUND

In the United States, sudden infant death syndrome (SIDS) is the leading cause of death in infants aged 1 month to 1 year. Approximately 3500 infants die from SIDS and sleep-related reasons on a yearly basis. Unintentional sleep-related deaths and bed sharing, a known risk factor for SIDS, are on the rise. Furthermore, ethnic disparities exist among those most affected by SIDS. Despite public health campaigns, infant mortality persists. Given the popularity of social media, understanding social media conversations around SIDS and safe sleep may assist the medical and public health communities with information needed to spread, reinforce, or counteract false information regarding SIDS and safe sleep.

OBJECTIVE

The objective of our study was to investigate the social media conversation around SIDS and safe sleep to understand the possible influences and guide health promotion efforts and public health research as well as enable health professionals to engage in directed communication regarding this topic.

METHODS

We used textual analytics to identify topics and extract meanings contained in unstructured textual data. Twitter messages were captured during September, October, and November in 2017. Tweets and retweets were collected using NUVI software in conjunction with Twitter's search API using the keywords: "sids," "infant death syndrome," "sudden infant death syndrome," and "safe sleep." This returned a total of 41,358 messages, which were analyzed using text mining and social media monitoring software.

RESULTS

Multiple themes were identified, including recommendations for safe sleep to prevent SIDS, safe sleep devices, the potential causes of SIDS, and how breastfeeding reduces SIDS. Compared with September and November, more personal and specific stories of infant loss were demonstrated in October (Pregnancy and Infant Loss Awareness Month). The top influencers were news organizations, universities, and health-related organizations.

CONCLUSIONS

We identified valuable topics discussed and shared on Twitter regarding SIDS and safe sleep. The study results highlight the contradicting information a subset of the population is exposed to regarding SIDS and the continued controversy over vaccines. In addition, this analysis emphasizes the lack of public health organizations' presence on Twitter compared with the influence of universities and news media organizations. The results also demonstrate the prevalence of safe sleep products that are embedded in safe sleep messaging. These findings can assist providers in speaking about relevant topics when engaging in conversations about the prevention of SIDS and the promotion of safe sleep. Furthermore, public health agencies and advocates should utilize social media and Twitter to better communicate accurate health information as well as continue to combat the spread of false information.

Cigarette smoke exposure effects on the brainstem expression of nicotinic acetylcholine receptors (nAChRs), and on cardiac, respiratory and sleep physiologies

Cigarette smoking during pregnancy is the largest modifiable risk factor for adverse outcomes in the infant. Investigations have focused on the psychoactive component of cigarettes, nicotine. One proposed mechanism leading to adverse effects is the interaction between nicotine and its nicotinic acetylcholine receptors (nAChRs). Much data has been generated over the past three decades on the effects of cigarette smoke exposure (CSE) on the expression of the nAChRs in the brainstem and physiological parameters related to cardiac, respiration and sleep, in the offspring of smoking mothers and animal models of nicotine exposure. This review summarises this data and discusses the main findings, highlighting that findings in animal models closely correlate with those from human studies, and that the major brainstem sites where the expression level for the nAChRs are consistently affected include those that play vital roles in cardiorespiration (hypoglossal nucleus, dorsal motor nucleus of the vagus, nucleus of the solitary tract), chemosensation (nucleus of the solitary tract, arcuate nucleus) and arousal (rostral mesopontine sites such as the locus coeruleus and nucleus pontis oralis). These findings provide evidence for the adverse effects of CSE during and after pregnancy to the infant and the need to continue with the health campaign advising against CSE.

Sudden Infant Death Syndrome: A Global Public Health Issue and Nursing's Response

Sudden unexplained death in infancy, including sudden infant death syndrome (SIDS), is a global public health challenge. Despite public health campaigns and efforts, SIDS remains the leading cause of postneonatal mortality in many developed countries. In this article, we review SIDS, describe nursing's unique professional position in addressing this problem, and explore how the principles of social justice can inform nursing's response. Motivated by nursing's ethical and moral obligations, the profession is called to take an active role in educating others regarding this phenomenon, to participate in research, and to develop or advocate for policy that aims to reduce the incidence of SIDS on an international scale.

Cot Death: History of an Iatrogenic Disaster

Since antiquity, cot death has been explained as accidental suffocation, overlaying, or smothering. Parents were blamed for neglect or drunkenness. A cage called arcuccio was invented around 1570 to protect the sleeping infant. Up to the 19th century, accidents were registered as natural causes of death. From 1830, accidental suffocation became unacceptable for physicians and legislators, and "natural" explanations for the catastrophe were sought, with parents being consoled rather than blamed. Two assumed causes had serious consequences: thymus hyperplasia was irradiated, causing thyroid cancer, and the concept of central apnea was widely accepted, which led to home monitors and distracted from epidemiological evidence. Prone sleeping originated in the 1930s and from 1944, it was associated with cot death. However, from the 1960s, many authors recommended prone sleeping for infants, and many countries adopted the advice. A worldwide epidemic followed, peaking at 2‰ in England and Wales and 5‰ in New Zealand in the 1980s. Although epidemiological evidence was available by 1970, the first intervention was initiated in the Netherlands in 1989. Cot death disappeared almost entirely wherever prone sleeping was avoided. This strongly supports the assumption that prone sleeping has the greatest influence on the disorder, and that the epidemic resulted from wrong advice.

A Fresh Look at the History of SIDS

Sudden infant death syndrome (SIDS) became a named entity in 1969 and the term has been used to certify sudden unexpected infant deaths meeting certain demographic, epidemiologic, and pathologic criteria. Since it is a diagnosis of exclusion, there is inherent imprecision, and this has led the National Association of Medical Examiners to recommend that these deaths now be classified as "undetermined." This historical review article briefly analyzes anecdotal instances of SIDS described centuries ago as overlying, smothering, infanticide, and suffocation by bedclothes followed by a more detailed review of "thymic" causes (i.e., thymic asthma and status thymicolymphaticus) popular in the late 1800s and early 1900s. Before the 1950s, such cases were also often categorized as accidental mechanical suffocation. In the 1940s and 1950s, forensic studies on infants dying unexpectedly revealed a typical pattern of autopsy findings strongly suggestive of natural causation and, after 1969, cases meeting the appropriate criteria were usually categorized as SIDS, a term embraced by the public and by advocacy groups. Research conducted after the 1960s identified important risk factors and generated many theories related to pathogenesis, such as prolonged sleep apnea. The incidence of SIDS deaths decreased sharply in the early 1990s after implementing public awareness programs addressing risk factors such as prone sleeping position and exposure to smoking. Deletion of cases in which death scene investigation suggested asphyxiation and cases where molecular autopsies revealed metabolic diseases further decreased the incidence. This historical essay lays the foundation for debate on the future of the SIDS entity.

Infant pacifiers for reduction in risk of sudden infant death syndrome

BACKGROUND

Sudden infant death syndrome (SIDS) has been most recently defined as the sudden unexpected death of an infant less than one year of age, with onset of the fatal episode apparently occurring during sleep, that remains unexplained after a thorough investigation, including the performance of a complete autopsy and a review of the circumstances of death and clinical history. Despite the success of several prevention campaigns, SIDS remains a leading cause of infant mortality. In 1994, a 'triple risk model' for SIDS was proposed that described SIDS as an event that results from the intersection of three factors: a vulnerable infant; a critical development period in homeostatic control (age related); and an exogenous stressor. The association between pacifier (dummy) use and reduced incidence of SIDS has been shown in epidemiological studies since the early 1990s. Pacifier use, given its low cost, might be a cost-effective intervention for SIDS prevention if it is confirmed effective in randomised controlled trials.

OBJECTIVES

To determine whether the use of pacifiers during sleep versus no pacifier during sleep reduces the risk of SIDS.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 2), MEDLINE via PubMed, Embase, and CINAHL to 16 March 2016. We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Published and unpublished controlled trials using random and quasi-random allocations of infants born at term and at preterm (less than 37 weeks' gestation) or with low birth weight (< 2500 g). Infants must have been randomised by one month' postmenstrual age. We planned to include studies reported only by abstracts, and cluster and cross-over randomised trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed studies from searches. We found no eligible studies.

MAIN RESULTS

We identified no randomised controlled trials examining infant pacifiers for reduction in risk of SIDS.

AUTHORS' CONCLUSIONS

We found no randomised control trial evidence on which to support or refute the use of pacifiers for the prevention of SIDS.

Sleep-Related Infant Deaths in Victoria: A Retrospective Case Series Study

BACKGROUND

There is general agreement that in some circumstances, sharing a sleep surface of any kind with an infant increases the risk of sudden unexpected death in infancy. There is a paucity of research conducted in Australia examining this issue. This study examines the frequency and distribution of sleep-related infant deaths in a defined population, and reports the proportion that occurred in the context of bed-sharing.

METHODS

A retrospective population-based case series study was conducted of infants (≤365 days) who died in a sleeping context during the period 1 January 2008 to 31 December 2010 in the state of Victoria, Australia. Information about the infant, caregiver, sleeping environment and bed-sharing was collected from a review of the coroner's death investigation record.

RESULTS

During the 3-year study period, 72 infant deaths occurred in a sleeping context. Of these, 33 (45.8 %) occurred in the context of bed-sharing: n = 7 in 2008; n = 11 in 2009; and n = 15 in 2010. Further analysis of the 33 deaths occurring in the context of bed-sharing showed that in this group, bed-sharing was largely intentional, habitual and most often involved the mother as one of the parties.

CONCLUSIONS

Given the case series nature of the study design, a causal relationship between bed-sharing and infant death could not be inferred. However the fact that nearly half of all sleep-related deaths occurred in the context of bed-sharing, provides strong support for the need to undertake definitive analytic studies in Australia so that evidence-based advice can be provided to families regarding the safety of bed-sharing practices.

Sudden infant death "syndrome"-Insights and future directions from a Utah population database analysis

"Sudden Infant Death syndrome" (SIDS) represents the commonest category of infant death after the first month of life. As genome scale sequencing greatly facilitates the identification of new candidate disease variants, the challenges of ascribing causation to these variants persists. In order to determine the extent to which SIDS occurs in related individuals and their pedigree structure we undertook an analysis of SIDS using the Utah Population Database, recording, for example, evidence of enrichment for genetic causation following the back-to-sleep recommendations of 1992 and 1994. Our evaluation of the pre- and post back-to-sleep incidence of SIDS in Utah showed a decrease in SIDS incidence on the order of eightfold following back-to-sleep. An odds ratio of 4.2 for SIDS recurrence among sibs was identified from 1968 to 2013 which was similar to the odds ratio of 4.84 for death due to other or unknown cause among sibs of SIDS cases for the same time period. Combining first through thid degree relatives yielded an odds ratio of SIDS recurrence of 9.29 in the post-back-to-sleep (1995-2013) subset of SIDS cases where similar calculations of first-third degree relatives for the entire time period of 1968-2013 showed an odds ratio of 2.95. Expanded multigenertional pedigrees showing enrichment for SIDS were also identified. Based on these findings we hypothesize that post back-to-sleep SIDS, especially recurrences within a family, are potentially enriched for genetic causes due to the impact of safe sleeping guidelines in mitigating environmental risk factors. © 2016 Wiley Periodicals, Inc.

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.

Bed Sharing, SIDS Research, and the Concept of Confounding: A Review for Public Health Nurses

Confounding is an important concept for public health nurses (PHNs) to understand when considering the results of epidemiological research. The term confounding is derived from Latin, confundere, which means to "mix-up" or "mix together". Epidemiologists attempt to derive a cause and effect relationship between two variables traditionally known as the exposure and disease (e.g., smoking and lung cancer). Confounding occurs when a third factor, known as a confounder, leads to an over- or underestimate of the magnitude of the association between the exposure and disease. An understanding of confounding will facilitate critical appraisal of epidemiological research findings. This knowledge will enable PHNs to strengthen their evidence-based practice and better prepare them for policy development and implementation. In recent years, researchers and clinicians have examined the relationship between bed sharing and sudden infant death syndrome (SIDS). The discussion regarding the risk of bed sharing and SIDS provides ample opportunity to discuss the various aspects of confounding. The purpose of this article is to use the bed sharing and SIDS literature to assist PHNs to understand confounding and to apply this knowledge when appraising epidemiological research. In addition, strategies that are used to control confounding are discussed.

Unintentional home injuries across the life span: problems and solutions

Home injuries cause more than 30,000 deaths and 12 million nonfatal injuries annually in the United States. They generate an estimated $222 billion in lifetime costs annually. Despite some data limitations in documenting home as the location of an injury, much progress has been made in identifying effective prevention strategies that reduce injury or mitigate risk behaviors. The current interest in public health in the role of housing in health offers unparalleled opportunities for injury prevention professionals concerned with home injuries. Sharing the science of injury prevention with the wide array of professionals-such as architects, home builders, home visitors, and fire and emergency medical services providers-who create home environments and interact with residents could be a useful approach. A collaborative national effort to reduce the burden of home injuries is needed.

Sudden unexpected postnatal collapse of newborn infants: a review of cases, definitions, risks, and preventive measures

This study aimed to review available published reports concerning sudden unexpected postnatal collapse (SUPC) of apparently healthy infants within the first days of postnatal life, establish a structured presentation and delineate recommendations for preventive measures. All published reports of SUPC cases were retrospectively analyzed, and three not previously published SUPC cases at Karolinska University Hospital were detailed to exemplify the varying presentations and outcomes of SUPC. We found 398 published cases of SUPC occurring during first postnatal week. Estimated incidence of the SUPC of a presumably healthy infant after birth differs widely, ranging from 2.6 cases to 133 cases/100,000. However, definition, inclusion, and exclusion criteria vary substantially between reports. Our summary indicates that reported SUPC occurs more frequently than expected from recent surveys. About half of the infants die, and of the remaining survivors, half have neurological sequela. Of the 233 cases of sudden unexpected death described, no etiology was found in 153 cases. When a defined time for the SUPC event is described, approximately one third of reported events occur during the first 2 h, between 2 and 24 h and between 1 and 7 days after birth, respectively. Adequate education of caregivers and appropriate surveillance during the first days of newborns should enable us to save hundreds of lives.

Endorsing safe infant sleep: a call to action

The American Academy of Pediatrics (AAP) safe sleep recommendations are considered best practice and are effective in preventing sudden infant death syndrome (SIDS). Yet studies have found that nurses' practice in newborn nurseries and neonatal intensive care units is often inconsistent with safe sleep recommendations. Such inconsistencies cause confusion and hinder SIDS prevention efforts. In 2011, the AAP added significant content to its 2005 safe sleep recommendations and neonatal nurses are now being asked to endorse the recommendations from birth. This article reviews the recommendations, examines barriers and controversies and offers suggestions for how an organization might initiate change and move toward a unified endorsement of safe sleep strategies.

Does cosleeping contribute to lower testosterone levels in fathers? Evidence from the Philippines

Because cross-species evidence suggests that high testosterone (T) may interfere with paternal investment, the relationships between men's transition to parenting and changes in their T are of growing interest. Studies of human males suggest that fathers who provide childcare often have lower T than uninvolved fathers, but no studies to date have evaluated how nighttime sleep proximity between fathers and their offspring may affect T. Using data collected in 2005 and 2009 from a sample of men (n = 362; age 26.0 ± 0.3 years in 2009) residing in metropolitan Cebu, Philippines, we evaluated fathers' T based on whether they slept on the same surface as their children (same surface cosleepers), slept on a different surface but in the same room (roomsharers), or slept separately from their children (solitary sleepers). A large majority (92%) of fathers in this sample reported practicing same surface cosleeping. Compared to fathers who slept solitarily, same surface cosleeping fathers had significantly lower evening (PM) T and also showed a greater diurnal decline in T from waking to evening (both p<0.05). Among men who were not fathers at baseline (2005), fathers who were cosleepers at follow-up (2009) experienced a significantly greater longitudinal decline in PM T over the 4.5-year study period (p<0.01) compared to solitary sleeping fathers. Among these same men, baseline T did not predict fathers' sleeping arrangements at follow-up (p>0.2). These results are consistent with previous findings indicating that daytime father-child interaction contributes to lower T among fathers. Our findings specifically suggest that close sleep proximity between fathers and their offspring results in greater longitudinal decreases in T as men transition to fatherhood and lower PM T overall compared to solitary sleeping fathers.

Sudden infant death syndrome: a re-examination of temporal trends

BACKGROUND

While the reduction in infants' prone sleeping has led to a temporal decline in Sudden Infant Death Syndrome (SIDS), some aspects of this trend remain unexplained. We assessed whether changes in the gestational age distribution of births also contributed to the temporal reduction in SIDS.

METHODS

SIDS patterns among singleton and twin births in the United States were analysed in 1995-96 and 2004-05. The temporal reduction in SIDS was partitioned using the Kitagawa decomposition method into reductions due to changes in the gestational age distribution and reductions due to changes in gestational age-specific SIDS rates. Both the traditional and the fetuses-at-risk models were used.

RESULTS

SIDS rates declined with increasing gestation under the traditional perinatal model. Rates were higher at early gestation among singletons compared with twins, while the reverse was true at later gestation. Under the fetuses-at-risk model, SIDS rates increased with increasing gestation and twins had higher rates of SIDS than singletons at all gestational ages. Between 1995-96 and 2004-05, SIDS declined from 8.3 to 5.6 per 10,000 live births among singletons and from 14.2 to 10.6 per 10,000 live births among twins. Decomposition using the traditional model showed that the SIDS reduction among singletons and twins was entirely due to changes in the gestational age-specific SIDS rate. The fetuses-at-risk model attributed 45% of the SIDS reduction to changes in the gestational age distribution and 55% of the reduction to changes in gestational age-specific SIDS rates among singletons; among twins these proportions were 64% and 36%, respectively.

CONCLUSION

Changes in the gestational age distribution may have contributed to the recent temporal reduction in SIDS.

Sudden unexpected infant deaths: sleep environment and circumstances

OBJECTIVES

We sought to describe the characteristics and sleep circumstances of infants who die suddenly and unexpectedly and to examine similarities and differences in risk factors among infants whose deaths are classified as resulting from sudden infant death syndrome (SIDS), suffocation, or undetermined causes.

METHODS

We used 2005 to 2008 data from 9 US states to assess 3136 sleep-related sudden unexpected infant deaths (SUIDs).

RESULTS

Only 25% of infants were sleeping in a crib or on their back when found; 70% were on a surface not intended for infant sleep (e.g., adult bed). Importantly, 64% of infants were sharing a sleep surface, and almost half of these infants were sleeping with an adult. Infants whose deaths were classified as suffocation or undetermined cause were significantly more likely than were infants whose deaths were classified as SIDS to be found on a surface not intended for infant sleep and to be sharing that sleep surface.

CONCLUSIONS

We identified modifiable sleep environment risk factors in a large proportion of the SUIDs assessed in this study. Our results make an important contribution to the mounting evidence that sleep environment hazards contribute to SUIDs.

Otolaryngological aspects of sudden infant death syndrome

INTRODUCTION

Sudden infant death syndrome (SIDS) is characterized by the sudden death of an apparently otherwise healthy infant, typically during sleep, and with no obvious case after a thorough post-mortem and scene death examination.

OBJECTIVE

To address the problem from the otolaryngologist's perspective, describe relevant pathologies, discuss controversies and suggest preventive measures in high-risk populations.

METHODOLOGY

A MEDLINE search and hand search were conducted to identify reports published between 1969 and 2011 in the English language on the pathophysiology of SIDS related to the head and neck organs. Search terms included SIDS (MeSH term), SIDS and pathophysiology (text words), and SIDS and autopsy (text words).

DISCUSSION

A growing number of reports suggested head and neck organs involvement in SIDS autopsies. Laryngeal, oropharyngeal, maxillofacial, otologic, cervical vascular abnormalities and infectious etiologies, were recognized and discussed.

CONCLUSIONS

Otolaryngologists should be aware of relevant pathologies, as some are treatable, if identified early enough in infancy. A proactive risk-management approach is warranted in infants presenting with certain abnormalities reviewed here.

Can home monitoring reduce mortality in infants at increased risk of sudden infant death syndrome? A systematic review

AIM

To conduct a systematic review to evaluate the effectiveness of home monitoring devices in the prevention of sudden infant death syndrome (SIDS).

METHODS

Systematic literature review to June 30, 2010.

RESULTS

Eleven unique studies were identified. Only one of these studies involved a comparison of home monitoring with a control intervention and so could be deemed level I evidence. The remaining studies constituted level III evidence.

CONCLUSIONS

There is no high-level evidence that home monitoring may be of use in preventing SIDS; further research is needed.

Critical diaphragm failure in sudden infant death syndrome

Sudden infant death syndrome (SIDS) is the leading cause of death in infants between the ages of 1 and 12 months in developed countries. SIDS is by definition a diagnosis of exclusion, and its mechanism of action is unknown. The SIDS-Critical Diaphragm Failure (CDF) hypothesis postulates that the cause of death in SIDS is respiratory failure caused by CDF. Four principal risk factors contribute to CDF in young infants: undeveloped respiratory muscles, non-lethal infections, prone resting position, and REM sleep. Even relatively minor infections can cause an acute and significant reduction in diaphragm force generation capacity that in conjunction with other risk factors can precipitate CDF. CDF-induced acute muscle weakness leaves few, if any pathological marks on the affected tissue.Understanding the underlying mechanism of SIDS may help in formulating new approaches to child care that can help to further reduce the incidence of SIDS.

High-protein diet in lactation leads to a sudden infant death-like syndrome in mice

Background

It is well accepted that reduced foetal growth and development resulting from maternal malnutrition are associated with a number of chronic conditions in later life. On the other hand such generation-transcending effects of over-nutrition and of high-protein consumption in pregnancy and lactation, a proven fact in all developed societies, are widely unknown. Thus, we intended to describe the generation-transcending effects of a high-protein diet, covering most relevant topics of human life like embryonic mortality, infant death, and physical health in later life.

Methods

Female mice received control food (21% protein) or were fed a high protein diet (42% protein) during mating. After fertilisation, females stayed on their respective diet until weaning. At birth, pups were put to foster mothers who were fed with standard food or with HP diet. After weaning, control diet was fed to all mice. All offspring were monitored up to 360 days after birth. We determined glucose-tolerance and measured cardiovascular parameters using a tip-catheter. Finally, abdominal fat amount was measured.

Results and Conclusions

We identified a worried impact of high-protein diet during pregnancy on dams' body weight gain, body weight of newborns, number of offspring, and also survival in later life. Even more important is the discovery that high-protein diet during lactation caused a more than eight-fold increase in offspring mortality. The observed higher newborn mortality during lactation is a hitherto non-described, unique link to the still incompletely understood human sudden infant death syndrome (SIDS). Thus, although offspring of lactating mothers on high-protein diet might have the advantage of lower abdominal fat within the second half of life, this benefit seems not to compensate the immense risk of an early sudden death during lactation. Our data may implicate that both pregnant women and lactating mothers should not follow classical high-protein diets.

Genetics of the sudden infant death syndrome

The sudden infant death syndrome (SIDS) is currently defined as "the sudden unexpected death of an infant less than 1 year of age with onset of the fatal episode apparently occurring during sleep, that remains unexplained after a thorough investigation". SIDS, whose etiology remains rather vague, is still the major cause of death among infants between 1 month and 1 year of age in industrialized countries with varying incidences in different populations. Herein, after touching on definitory approaches and several current hypotheses concerning SIDS etiology, we focus on the triple risk model of SIDS and discuss two large classes of genetic factors potentially contributing to or predisposing for the generation of a vulnerable infant that, when encountering an environmental trigger, may succumb to SIDS. We conclude by acknowledging that for the integration of the vast and complex genetic evidence concerning SIDS, a lot more research will be required and we briefly discuss the potential use of recently presented animal models for functional studies of SIDS pathology.