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ObjectivesTo determine the rate of sudden unexpected death in infancy (SUDI) for infants born after a previous SUDI in the same family, and to establish the causes of death and the frequency of child protection concerns in families with recurrent SUDI.DesignObservational study using clinical case records.SettingThe UK’s Care of Next Infant (CONI) programme, which provides additional care to families who have experienced SUDI with their subsequent children.PatientsInfants registered on CONI between January 2000 and December 2015.Main outcome measuresCause of death, presence of modifiable risk factors for SUDI and child protection concerns.ResultsThere were 6608 live-born infants registered in CONI with 29 deaths. 26 families had 2 deaths, and 3 families had 3 deaths. The SUDI rate for infants born after one SUDI is 3.93 (95% CI 2.7 to 5.8) per 1000 live births. Cause of death was unexplained for 19 first and 15 CONI deaths. Accidental asphyxia accounted for 2 first and 6 CONI deaths; medical causes for 3 first and 4 CONI deaths; and homicide for 2 first and 4 CONI deaths. 10 families had child protection concerns.ConclusionsThe SUDI rate for siblings is 10 times higher than the current UK SUDI rate. Homicide presenting as recurrent SUDI is very rare. Many parents continued to smoke and exposed infants to hazardous co-sleeping situations, with these directly leading to or contributing to the death of six siblings. SUDI parents need support to improve parenting skills and reduce risk to subsequent infants.

Bed-sharing refers to a baby and adult (usually mother) sleeping together on the same sleep surface (usually a bed) for some or all sleeps. Previous Scottish Government Reduce the Risk of Cot death advice, endorsed by the Scottish Cot Death Trust and Unicef, included: “The safest place for your baby to sleep at night, during the first six months, is on their back in a cot in your room.” Figure 1A illustrates the cot where the baby should sleep after a feed or cuddle. Figure 1 Feeding your baby in bed (A) with a cot next to bed (B) with no cot next to bed. The Scottish Government is now issuing the Lullaby Trust’s Safer Sleep-Saving Babies Lives leaflets for professionals (https://www.lullabytrust.org.uk/wp-content/uploads/Safer-sleep-saving-lives-a-guide-for-professionals-web.pdf) and parents (https://www.lullabytrust.org.uk/wp-content/uploads/Safer-sleep-for-babies-a-guide-for-parents-web.pdf) endorsed by Public Health England, which use clipart similar to figure 1B with no infant cot to indicate the safest place for your baby to sleep after a feed or cuddle. The Scottish Government now recommends avoidance of bed-sharing only if additional hazards are present such as parental smoking, alcohol or drug use or sleeping on a sofa. We believe this written literature—without spelling out inherent risk of bed-sharing for sleep and only recommending against bed-sharing if additional hazards are present—in conjunction with figure 1B with no infant cot to indicate the safest place for your baby to sleep, will encourage more parents to share their adult bed with their young baby and lead to many otherwise avoidable infant deaths. Bed-sharing is associated with sudden unexpected death in infancy (SUDI). SUDI includes SIDS (also known as cot death) (International Classification of Diseases ICD-10 …

ObjectiveTo develop a detailed understanding of the circumstances of sudden unexpected death in infancy (SUDI) cases subject to serious case review (SCR).DesignThis was a thematic analysis of SCRs relating to cases of SUDI in England. SCRs were obtained for SUDI cases dying between 1 April 2011 and 31 March 2014. These were cases (aged 0–2 years) that presented as a SUDI and for which no clear medical or forensic cause of death was found.ResultsSCRs were held for 30 SUDI cases, published reports were available for 27/30. The median (range) age at death was 2 (0–19) months. Background risk factors in families included: alcohol or drug dependency in 18/27, parental mental health problems in 14/27, domestic abuse in 9/27 and parental criminal records in 13/27. Nineteen infants had received support from social care, 10/19 were subject to child protection plans. Neglect was a feature in 15/27 cases. Parents did not engage with professionals in 18/27 cases, involving social care in 14/18, health care in 13/18 and drug and substance misuse services in 5/18. Eighteen of 27 deaths occurred in highly hazardous sleep environments, 16/18 involved cosleeping and 13/16 cosleeping deaths occurred with parents who were intoxicated with alcohol or impaired by drugs.ConclusionMost SUDI cases occurred in hazardous sleep environments and are potentially preventable. They occurred in families well known to services with concerns about neglect, substance misuse and poor engagement. More consideration is needed on how best to support such vulnerable families.

ObjectiveTo compare overnight oxygen saturation, heart rate and the thermal environment of infants sleeping in an indigenous sleep device (wahakura) or bassinet to identify potential risks and benefits.DesignRandomised controlled trial.SettingFamily homes in low socio-economic areas in New Zealand.Patients200 mainly Māori mothers and their infants.InterventionsParticipants received a wahakura or bassinet from birth.Main outcome measuresOvernight oximetry, heart rate and temperature at 1 month.ResultsIntention-to-treat analysis for 83 bassinet and 84 wahakura infants showed no significant differences between groups for the mean time oxygen saturation (SpO2) was less than 94% (0.54 min, 95% CI -1.36 to 2.45) or less than 90% (0.22 min, 95% CI -0.56 to 1.00), the mean number of SpO2dips per hour >5% (-0.19, 95% CI -3.07 to 2.69) or >10% (-0.41, 95% CI -1.63 to 0.81), mean heart rate (1.99 beats/min, 95% CI -1.02 to 4.99), or time shin temperature >36°C (risk ratio (RR): 0.63, 95% CI 0.13 to 2.99) or ConclusionsThis indigenous sleep device is at least as safe as the currently recommended bassinet, which supports its use as a sleep environment that offers an alternative way of bed-sharing.Trial registration numberAustralian New Zealand Clinical Trials Registry: ACTRN12610000993099.

ObjectiveTo investigate mothers’ knowledge of reducing the risks for sudden infant death syndrome (SIDS) and attitudes towards safer sleep practices.Design and settingA cross-sectional survey was carried out in deprived areas of Bristol, UK. Recruitment took place in 2014 at local health visitor-led baby clinics.ParticipantsOf 432 mothers approached, 400 (93%) completed the face-to-face survey. Participants with infants at ‘higher’ risk of SIDS (using an algorithm based on a previous observational study) were compared with those at ‘lower’ risk.Main outcome measuresThe survey asked participants to recall three SIDS risk reduction strategies (unprompted), and scored responses to 14 SIDS risk-related infant sleep scenarios (prompted).ResultsOverall, 48/400 (12%) mothers were classified as higher risk. Mothers in the higher risk group were less likely to breast feed (multivariate OR=3.59(95% CI 1.46 to 8.86)), less likely to be able to cite two or more unprompted correct SIDS risk reduction strategies (multivariate OR=2.05(95% CI 1.02 to 4.13)) and scored lower on prompted safer sleep scenarios overall.Notably, only 206/400 (52%) of all mothers surveyed (33% in the higher risk group) from these deprived areas in Bristol identified infant sleep position as a risk reduction strategy for SIDS, despite 25 years of campaigns.ConclusionsMothers in the higher risk group were disadvantaged when it came to some aspects of knowledge of SIDS risk reduction and attitudes to safer sleep. The initial ‘Back-to Sleep’ message that dramatically reduced these deaths a generation ago needs more effective promotion for today’s generation of mothers.

Despite decades of investigation and millions of dollars spent, the cause of sudden infant death syndrome (SIDS) eludes researchers. It is timely therefore to reconsider the reasons for this failure and to explore how research might go forward with better prospects. This review assesses SIDS research in the context of clinicopathological and epidemiological features and determines that only infection attains congruence.

We read with great interest, ‘A national registry for sudden unexpected deaths of infants and children in England: why do we need one and do families want one?’1 In the USA’s experience, getting feedback from parents and other stakeholders was an important first step to implementing sudden unexpected infant death (SUID) and sudden death in the young (SDY) registries.2 3 Starting a registry in England is key to better understanding the causes of these tragic deaths so they can be prevented. Although mortality data derived from death certificates are often used to monitor and track trends in sudden deaths among infants and children, death certificate surveillance has limited ability to capture details of the events and circumstances surrounding these deaths.2 In addition, for infants, US death certificate surveillance is affected by variations in cause-of-death reporting, making it necessary to combine underlying cause-of-death codes for SIDS, other ill-defined and unspecified causes of mortality, and accidental suffocation and strangulation in bed into a combined category, SUID.4 Although the SUID category facilitates more consistent tracking of mortality trends, the combined category does not enable researchers to distinguish between explained (eg, accidental suffocation) and unexplained causes (eg, unexplained sudden deaths).4 To address these shortcomings in surveillance, the US Centers for Disease Control and Prevention (CDC) and the US National Institutes of Health (NIH) established SUID (infants

Despite the fall in numbers of unexpected infant deaths that followed the ‘Back to Sleep’ campaigns in the early 1990s in the UK and many other countries, such deaths remain one of the largest single groups of deaths in the postneonatal period in many Western countries. Changes in the ways in which unexpected infant deaths are categorised by pathologists and coroners, and increasing reluctance to use the term ‘sudden infant death syndrome’, make assessment of nationally and internationally collected data on incidence potentially inaccurate and confusing. In this paper, we review current understanding of the epidemiology and aetiology of unexpected deaths in infancy, and current hypotheses on the pathophysiology of the processes that may lead to death. We also review interventions that have been adopted, with variable degrees of effectiveness in efforts to reduce the numbers of deaths, and new approaches that offer the possibility of prevention in the future.

Objective To describe experience of long QT (LQT) molecular autopsy in sudden infant death syndrome (SIDS). Design Descriptive audit from two distinct periods: (1) A prospective, population-based series between 2006 and 2008 (‘unselected’). (2) Before and after 2006–2008, with testing guided by a cardiac genetic service (‘selected’). LQT genes 1, 2, 3, 5, 6 and 7 were sequenced. Next of kin were offered cardiac evaluation. Setting New Zealand. Patients 102 SIDS cases. Interventions Nil. Main outcome measures Detection of genetic variants. Results Maori 49 (47%), and Pacific island 24 (23%), infants were over-represented. Risk factors were common; bed sharing was reported in 49%. Rare genetic variants were commoner within the selected than unselected populations (5 of 31 infants (16%) vs 3 of 71 infants (4%) p

ObjectiveTo investigate factors influencing African-American parents’ knowledge, attitudes and practice regarding infant sleep position and determine if these differ by socioeconomic status (SES).MethodsA cross-sectional sample of 412 parents with infants ≤6 months of age participated in a validated survey of knowledge, attitudes and practice.ResultsThere was no significant difference in attitudes or practice, and knowledge was similar regarding infant sleep position between African-American parents of higher and lower SES. The healthcare provider recommendation of exclusive supine sleep position use was associated with increased knowledge, overall decreased use of the side position (5.0% vs 16.8%, pConclusionsSleep position practices in African-American families do not differ by SES. Improved attitudes toward positioning and increased use of supine positioning may result if healthcare providers address common concerns and misconceptions about sleep position.

To examine the incidence of sudden unexplained death in children 1-4 years old (SUDC) in Ireland and to compare the epidemiological profile of SUDC with that of SIDS.All cases of sudden unexplained death in children5 years in Ireland between 1994 and 2008 were reviewed. Epidemiological information obtained from parental questionnaires and post-mortem reports was examined, and data on cases ≥52 weeks compared with cases52 weeks.SUDC accounted for 5% (n=44) of deaths in children aged 1-4 years during 1994-2008. During this period, the SIDS rate dropped from 0.71 to 0.34 per 1000 live births, while the SUDC rate increased from 0.08 to 0.18 deaths per 10 000 population aged 1-4 years. The median age of SUDC cases was 71.5 weeks, and the male/female ratio was 1.3:1. All died during a sleep period, 71% between 10pm and 8am, and more than two-thirds were found prone. Fewest cases occurred during July-September (11%), and a greater proportion occurred at weekends (55%). 52% (17/33) had symptoms (any) in the 48 h before death, and 35% (11/31) visited their general practitioner because of illness in the week preceding death. SUDC differed from SIDS in prevalence of maternal smoking (38% vs 72%, p0.001), bed-sharing (17% vs 49%, p0.001), and whether found prone (72% vs 23%, p0.001).While SUDC shares some characteristics with SIDS, there are also some important differences. Further data collection will help determine whether SIDS and SUDC represent the same pathophysiological entity. Standardisation of protocols for investigating sudden deaths is urgently required for accurate diagnosis of cases.

Background: The aetiology of infantile hypertrophic pyloric stenosis (IHPS) has not been fully elucidated. Since the 1990s, a sharp decline in IHPS has been reported in various countries. Recent research from Sweden reported a correlation between falling rates of IHPS and of sudden infant death syndrome (SIDS). This was attributed to a reduction in the number of infants sleeping in the prone position following the “Back to Sleep” campaign. Objectives: To describe the changing epidemiology of IHPS in Scotland, to examine the relationship between IHPS and SIDS rates and to examine trends in other factors that may explain the observed reduction in IHPS incidence. Design: Incidence rates of IHPS and SIDS were derived from routine data and their relationship analysed. Trends in mean maternal age, maternal smoking, mean birth weight and breastfeeding rates were also examined. Setting: The whole of Scotland between 1981 and 2004. Results: IHPS incidence fell from 4.4 to 1.4 per 1000 live births in Scotland between 1981 and 2004. Rates were consistently higher in males, although the overall incidence patterns in males and females were similar. Rates showed a positive relationship with deprivation. The fall in the incidence of IHPS preceded the fall in SIDS by 2 years and the incidence of SIDS displayed less variability than that of IHPS. Significant temporal trends were also observed in other maternal and infant characteristics. Conclusion: There has been a marked reduction in Scotland’s IHPS incidence, but this is unlikely to be a consequence of a change in infant sleeping position.

Background: Some victims of sudden infant death syndrome (SIDS) are found with their heads covered with bedclothes, but the significance of this is uncertain. The aim of this review is to describe the prevalence of head covering, the magnitude of the risk and how far the suggested causal mechanisms agree with current epidemiological evidence. Methods: Systematic review of population-based age-matched controlled studies. Results: Controlled observations of head covering for the final sleep were found in 10 studies. The pooled prevalence in SIDS victims was 24.6% (95% CI 22.3% to 27.1%) compared to 3.2% (95% CI 2.7% to 3.8%) among controls. The pooled univariate odds ratio (OR) was 9.6 (95% CI 7.9 to 11.7) and the pooled adjusted OR from studies mainly conducted after the fall in SIDS rate was 16.9 (95% CI 12.6 to 22.7). The risk varied in strength but was significant across all studies. In a quarter of cases and controls head covering had occurred at least once previously (pooled adjusted OR = 1.1; 95% CI 0.9 to 1.4). The population attributable risk (27.1%; 95% CI 24.7% to 29.4%) suggests avoiding head covering might reduce SIDS deaths by more than a quarter. Conclusions: The epidemiological evidence does not fully support postulated causal mechanisms such as hypoxia, hypercapnoea and thermal stress, but neither does it support the idea that head covering is part of some terminal struggle. Head covering is a major modifiable risk factor associated with SIDS deaths and parental advice to avoid this situation should be emphasised.

Background: As episodes of decreased oxygenation levels have been recorded in premature infants placed in car seats, it is believed that these infants are at risk of life-threatening events and death. No data on the prevalence of such infant deaths are available. The aim of our study was to determine the incidence of sudden deaths in infants occurring in sitting devices in a whole population and to determine whether premature infants account for a disproportionate number of these deaths. Design: Retrospective population-based cohort study reviewing all cases of sudden unexpected death in infants between birth and 1 year of age that occurred in the province of Quebec between January 1991 and December 2000. Results: Of the 508 deaths reviewed, 409 were unexplained and 99 were explained after investigation. Seventeen deaths occurred in a sitting device, of which 10 were unexplained. There was no excess of premature infants dying. However, there was an excess of infants of less than 1 month of age found to have died in a sitting position in the unexplained death group. In addition, three infants who died in a sitting position had an increased risk of upper airway obstruction. Conclusion: Although very few deaths occurred in car seats, our results suggest that caution should be used when placing younger infants in car seats and similar sitting devices, whether the infants have been born prematurely or not. We also recommend that more attention be given to infants at increased risk of upper airway obstruction.

Objective: To compare transthoracic impedance (TTI/ECG) and pulse oximetry alarm traces detected during home monitoring in infants at risk of apnoea, bradycardia and hypoxaemia. Study design: A retrospective evaluation of the monitor downloads of 67 infants who had undergone either TTI/ECG or pulse oximetry home monitoring using a device which can detect both parameters. Methods: The patients were categorised as: apparent life-threatening events (n = 39), preterm infants (n = 21) and miscellaneous (n = 7). TTI/ECG and pulse oximetry alarm traces were scored as either true or false alarms. Classification criteria were based on visual analysis of the impedance and plethysmographic waveforms captured by the memory monitor every time alarm thresholds were violated. Results: 5242 alarms occurred over 3452 days of monitoring: 4562 (87%) were false and 680 (13%) true. The mean duration of monitoring was 51 days (range 5–220 days). There were 2982 TTI/ECG false alarms (65% of the total) and 1580 pulse oximetry false alarms (35%) (p = 0.0042). Of the 680 true alarms, 507 (74%) were desaturations not attributable to central apnoea and 173 (26%) were true TTI/ECG alarms (p = 0.0013). Conclusions: Comparison of pulse oximetry and TTI/ECG alarm traces shows that true events were mostly attributable to desaturations, while false alarms were mainly provoked by TTI/ECG. The total number of false alarms is lower than reported in other studies using TTI/ECG only, thus indicating that monitoring using both pulse oximetry and TTI/ECG is suitable for home use. When the combination of both techniques is not feasible or not required, we recommend the use of motion resistant pulse oximetry alone.

Objective: This study was undertaken to determine the role of opiate use during pregnancy as a predisposing factor for sudden infant death syndrome (SIDS) in infants born to HIV-infected mothers. Methods: In order to identify all infant deaths and their cause and association with maternal opiate use, the data of a nationwide prospective cohort study of HIV-infected mothers and their children were extracted and analysed for a 13-year period. Results: 24 (5.1%) infant deaths were observed out of 466 infants followed up until death or at least 12 months of life. 3 (0.6%) of them were due to non-accidental trauma and were not associated with maternal opiate use. 7 (1.5%) died due to SIDS, which was confirmed by autopsy. All SIDS cases occurred in infants born to mothers reporting use of opiates during pregnancy (n = 124). The relative risk of SIDS compared to the general population was 18 (95% CI 9 to 38) for all infants of HIV-infected mothers, and 69 (95% CI 33 to 141) for those with intrauterine opiate exposure (p Conclusions: Compared to the Swiss general population, the risk for SIDS in this cohort of infants born to HIV-infected mothers was greatly increased, but only for mothers reporting opiate use during pregnancy. This effect appeared not to be mediated by prematurity, low birth weight, perinatal HIV infection or antiretroviral drug exposure.

The recognition of risk factors for unexpected and unexplained infants deaths (sudden infant death syndrome, (SIDS))—most importantly the risk associated with the prone sleeping position—and the implementation of risk reduction public health campaigns (eg, the ‘Back to Sleep’ campaigns in the UK in 1991 and the USA in 1994) was followed in many countries by a significant fall in the number of such deaths. In England and Wales, the overall post-neonatal mortality (PNM) rates fell in parallel with the recorded fall in SIDS, and continued to fall over the next decade, providing evidence that the fall in SIDS was not solely a consequence of diagnostic transfer.1 ,2 International comparisons of SIDS rates have been hampered by the wide variation in quality of investigation after unexpected infant deaths—particularly with regard to death-scene investigations and autopsy rates and procedures. A further impediment to effective international comparisons has been the way in which unexpected and unexplained deaths are categorised in different jurisdictions. In the UK, the increasing use since the late 1990s of the term ‘unascertained’ rather than SIDS by some pathologists has led to further uncertainty, as these terms may translate into different International classification of Diseases, Version 10 (ICD-10) codes.3 Further uncertainty arises from the concept of how much pathology is required to fully explain an unexpected death; for instance, practising paediatricians will commonly see children who survive an illness despite radiological evidence of severe pneumonia. In …

BackgroundComparing rates of sudden unexpected death in infancy (SUDI) in different countries and over time is difficult, as these deaths are certified differently in different countries, and, even within the same jurisdiction, changes in this death certification process have occurred over time.AimsTo identify if International Classification of Diseases-10 (ICD-10) codes are being applied differently in different countries, and to develop a more robust tool for international comparison of these types of deaths.MethodsUsage of six ICD-10 codes, which code for the majority of SUDI, was compared for the years 2002–2010 in eight high-income countries.ResultsThere was a great variability in how each country codes SUDI. For example, the proportion of SUDI coded as sudden infant death syndrome (R95) ranged from 32.6% in Japan to 72.5% in Germany. The proportion of deaths coded as accidental suffocation and strangulation in bed (W75) ranged from 1.1% in Germany to 31.7% in New Zealand. Japan was the only country to consistently use the R96 code, with 44.8% of SUDI attributed to that code. The lowest, overall, SUDI rate was seen in the Netherlands (0.19/1000 live births (LB)), and the highest in New Zealand (1.00/1000 LB). SUDI accounted for one-third to half of postneonatal mortality in 2002–2010 for all of the countries except for the Netherlands.ConclusionsThe proposed set of ICD-10 codes encompasses the codes used in different countries for most SUDI cases. Use of these codes will allow for better international comparisons and tracking of trends over time.

ObjectivesSudden unexplained death in children is a tragic and traumatic event, often worsened when the cause of death cannot be determined. This work aimed to investigate the presence of putative pathogenic genetic variants in a broad spectrum of cardiomyopathy, channelopathy and aortic disease associated genes that may have increased these children's vulnerability to sudden cardiac death.DesignWe performed molecular autopsy of 41 cases of sudden unexplained death in infants and children through massive parallel sequencing of up to 86 sudden cardiac death-related genes. Multiple in silico analyses were conducted together with a thorough review of the literature in order to prioritise the putative pathogenic variants.ResultsA total of 63 variants in 35 cases were validated. The largest proportion of these variants is located within cardiomyopathy genes although this would have been more expected of channelopathy gene variants. Subtle microscopic features of heart tissue may indicate the presence of an early onset cardiomyopathy as a predisposing condition to sudden unexpected death in some individuals.ConclusionsNext-generation sequencing technologies reveal the existence of a wide spectrum of rare and novel genetic variants in sarcomere genes, compared with that of cardiac ion channels, in sudden unexplained death in infants and children. Our findings encourage further investigation of the role of early onset inherited cardiomyopathies and other diseases involving myocardial dysfunction in these deaths. Early detection of variants in these individuals could help to unmask subtle forms of disease within their relatives, who would eventually benefit from better counselling about their genetic history.

Objective: To compare the current prevalence of risk factors for sudden infant death syndrome (SIDS) in Sweden with a decade earlier, and assess factors associated with prone sleeping. Methods: The results of a cohort study (Infants of Western Sweden) and a population based case-control study (Nordic Epidemiological SIDS Study) were examined. Subjects were 5600 healthy 6 month old infants born in 2003 in the Western Sweden region and 430 healthy Swedish infants born between 1991 and 1995. Results: Prone sleeping decreased from 31.8% to 5.6% and supine sleeping increased from 35.3% to 47.3%. Side or side/supine sleeping increased from 25.2% to 43.8%. Maternal smoking during pregnancy decreased from 23.5% to 9.5%. The risk for prone sleeping increased if the mother was unemployed (OR 2.4, 95% CI 1.5 to 4.0), if she was a heavy smoker in the third trimester (OR 44.1, 95% CI 1.6 to 1199.6), and if the child was irritable (OR 2.5, 95% CI 1.3 to 5.1), shared a bedroom with siblings (OR 2.6, 95% CI 1.0 to 6.6), or never used a dummy (OR 3.2, 95% CI 1.9 to 5.4). Conclusions: Parents have complied with advice to prevent SIDS given at infant welfare centres for the last 10 years. A change in the preferred sleeping position from side variants to exclusively supine, and reducing the number of pregnant women smoking may be beneficial. Use of a prone sleeping position was associated with maternal employment status, maternal smoking, temperament of the child, dummy use, and sharing a bedroom with siblings.

Background: In Germany, 2910 infants died in 2004; for many infants the reason was clear, especially prematurity or congenital abnormalities. However, 394 babies die every year suddenly and unexpectedly. The cause may be immediately clear, but is often not obvious. Aims: (1) To describe the causes of explained sudden unexpected death in infancy (SUDI) and (2) to compare risk factors for sudden infant death syndrome (SIDS) and explained SUDI. Methods: A 3-year population-based case–control study in Germany, 1998–2001. Results: 455 deaths, of which 51 (11.2%) were explained. Most of these deaths were due to respiratory or generalised infections. The risk factors for SIDS and explained SUDI were remarkably similar except for sleep position and breast feeding. Prone sleeping position is a major risk factor for SIDS (adjusted odds ratio (OR) 7.16, 95% confidence interval (CI) 3.85 to 13.31) but not for explained SUDI (adjusted OR 1.71, 95% CI 0.25 to 11.57). Not being breast fed in the first 2 weeks of life is a risk factor for SIDS (adjusted OR 2.37, 95% CI 1.46 to 3.84) but not for explained SUDI (adjusted OR 0.39, 95% CI 0.08 to 1.83). Conclusions: Prone sleeping position is a unique risk factor for SIDS. Socioeconomic disadvantage and maternal smoking are risk factors for both SIDS and explained SUDI, and provide an opportunity for targeted intervention.

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.

Background: Mortality from SIDS has declined since the recommendation that infants are not placed prone to sleep. SIDS mortality is higher in infants born preterm than those born at term. Aim: To determine if risk factors for SIDS are any different for preterm and term infants. Methods: Mortality data over time were used to determine whether the reduction in SIDS mortality rates had occurred equally in term and preterm infants. Data from two New Zealand studies (a case-control study and a case-cohort study) were used to determine if any differences existed in risk factors for SIDS between term and preterm infants before and after the SIDS prevention campaign. Results: SIDS mortality appears to have decreased by similar proportions in term and preterm infants. Risk factors for SIDS were similar in preterm and term infants, except for parity where there was a significant interaction. Increasing parity was a risk factor for SIDS in term infants but not preterm infants. Conclusion: SIDS rates have decreased at comparable rates in term and preterm infants, but preterm birth still remains a risk factor for SIDS. The magnitude of the odds ratios associated with modifiable risk factors were similar for both groups. There may however be a difference in risk associated with parity between term and preterm infants. The messages for risk factors for SIDS are applicable to mothers of preterm as well as term infants.

Aims: To investigate the epidemiology and risk factors of apparent life threatening events (ALTE). Methods: A prospective study enrolled all live-born infants in the Tyrol (1993–2001). Information on pregnancy, sociodemographic characteristics, child care practices, and infant’s behaviour in the first four to six weeks of life was collected with a standardised questionnaire, and was available for 44 184 infants. ALTE was identified from hospital admission records. Results: During the study period 164 ALTE cases were identified, corresponding to an incidence of 2.46/1000 live births. In 73 of these infants no cause for the event and no comorbidity could be found (idiopathic ALTE). On average ALTE manifested ten weeks earlier than SIDS. Of various SIDS risk factors in the survey area, the prone sleeping position, smoking during pregnancy, low gestational age, profuse night sweating, and family history of infant death showed a moderate relation to the risk of overall ALTE, but only smoking maintained significance in the multivariate risk model. None of these variables was associated with idiopathic ALTE. In contrast to SIDS the frequency of ALTE did not change during the study period. None of the ALTE infants experienced SIDS later in life. Behavioural abnormalities such as feeding difficulties, episodes of pallor, cyanotic episodes, and repeated apnoea episodes were strongly associated with an increased risk of overall and idiopathic ALTE. Conclusions: Although there are some similarities in the clinical presentation and epidemiology of SIDS and ALTE, differences clearly predominate. Accordingly, ALTE and SIDS should not be considered different manifestations of the same disease process.

From the perspective of systems biology, genes and proteins interact to produce complex networks, which in turn interact with the environment to influence every aspect of our biological lives. Recent advances in molecular genetics and the identification of gene polymorphisms in victims of sudden infant death syndrome (SIDS) are helping us better to understand that SIDS, like all other human conditions in health and disease, represents the confluence of specific environmental risk factors interacting in complex ways with specific polymorphisms to yield phenotypes susceptible to sudden and unexpected death in infancy. Failure to consider both genetic and environmental risk factors will impede research progress.

Background: In the Netherlands, there is a very low incidence of sudden infant death syndrome (SIDS) due to effective preventive campaigns. Methods: During the period September 1996 to August 2002, nationwide 161 deaths from SIDS (about 85% of all cases of SIDS during that time) were investigated by the Cot Death Committee of the Dutch Paediatric Association. Results and Discussion: Over 10% of cases of SIDS took place during some type of child care. From a national survey carried out in 2000/01 information was available on the child care attendance of 2000 Dutch infants aged 3-6 months. Based on the hours usually spent in child care by these infants, the number of similarly aged infants that died from SIDS while attending child care was 4.2 times higher than expected. Remarkably, the prevalence of known risk factors for SIDS, such as sleeping position and parental smoking, was favourable in the SIDS cases in child care settings. The adherence of child care facilities to the safe sleeping recommendations is high in the Netherlands, and no explanation as to why child care settings may be associated with an increased risk of SIDS is apparent. The possibility of other explanations, such as stress and change in routine care, is hypothesised.

Aims: To investigate the influence of analytical design on the variability of published results in studies of sudden infant death syndrome (SIDS). Methods: The results of a prospective case-control study, of 203 cases of SIDS, and 622 control infants are presented. All variables significant on univariate analysis were included in a multivariate model analysed in nine stages, starting with sociodemographic variables, then sequentially and cumulatively adding variables relating to pregnancy history, current pregnancy, birth, the interval from birth to the week prior to death, the last week, the last 48 hours, and the last sleep period. A ninth stage was created by adding placed to sleep prone for the last sleep period. Results: As additional variables are added, previously published SIDS risk factors emerged such as social deprivation, young maternal age, ⩾3 previous live births, maternal smoking and drinking, urinary tract infection in pregnancy, reduced birth weight, and the infant having an illness, regurgitation, being sweaty, or a history of crying/colic in the interval from birth to the week before death, with co-sleeping and the lack of regular soother use important in the last sleep period. As the model progressed through stages 1–9, many significant variables became non-significant (social deprivation, young maternal age, maternal smoking and drinking) and in stage 9 the addition of placed to sleep prone for the last sleep period caused ⩾3 previous live births and a reduced birth weight to become significant. Conclusion: The variables found to be significant in a case-control study, depend on what is included in a multivariate model.

This review explores the various research approaches taken attempting to solve the problem of SIDS. It would appear that major clues provided by pathological findings have been largely overlooked and as a consequence much effort, time, and money has been wasted on projects that satisfy only sub-specialty and political needs. Close examination of the pathological clues would provide better insights into the mechanisms underlying this enigmatic and heartbreaking problem.

Aims: to describe a pattern of illness in “normal” infants, and to assess to what extent this may differ in infants who die suddenly and unexpectedly. Methods: All infants are on the CONI (Care of the Next Infant) scheme in which mothers record symptoms and signs of illness prospectively, on a daily basis from birth to approximately age 6 months. The symptoms of infants who die suddenly and unexpectedly are compared with those of a consecutive sample of infants who survive. Twenty one babies died suddenly, of whom 11 were cot deaths and 10 had “known causes” of death. Ninety eight infants who survived were used as consecutive controls. Prospective daily records of the presence or absence of 26 signs and symptoms were kept by all of the mothers, commencing at birth and lasting an average of 176 days in survivors; 84 days in SIDS; and 93 days in infants who died of known causes. Results: Standardised for age and the time of year, on any given day, the mothers of the SIDS infants were over eight times more likely to record their child as being pale, six times more likely to be sweating, and twice as likely to be irritable. Other signs and symptoms which were three times more likely to be recorded were sore gums, dry stools, and coldness. Infants who died of known causes generally had fewer symptoms. Conclusions: Cot death infants have a range of symptoms which appear to be of a general nature, and not related to any one system. Symptoms are seen throughout life and not related to the time of death.

Aims: To determine whether the risk factors for SIDS occurring at night were different from those occurring during the day. Methods: Large, nationwide case-control study, with data for 369 cases and 1558 controls in New Zealand. Results: Two thirds of SIDS deaths occurred at night (between 10 pm and 7 30 am). The odds ratio (95% CI) for prone sleep position was 3.86 (2.67 to 5.59) for deaths occurring at night and 7.25 (4.52 to 11.63) for deaths occurring during the day; the difference was significant. The odds ratio for maternal smoking for deaths occurring at night was 2.28 (1.52 to 3.42) and that for the day 1.27 (0.79 to 2.03); that for the mother being single was 2.69 (1.29 to 3.99) for a night time death and 1.25 (0.76 to 2.04) for a daytime death. Both interactions were significant. The interactions between time of death and bed sharing, not sleeping in a cot or bassinet, Maori ethnicity, late timing of antenatal care, binge drinking, cannabis use, and illness in the baby were also significant, or almost so. All were more strongly associated with SIDS occurring at night. Conclusions: Prone sleep position was more strongly associated with SIDS occurring during the day, whereas night time deaths were more strongly associated with maternal smoking and measures of social deprivation.

ObjectiveTo report mortality in babies enrolled on a community-based programme, Care of Next Infant Plus (CONI PLUS), which primarily supports parents anxious because of previous sudden unexpected death in infancy (SUDI) in their extended family or following an apparent life threatening event (ALTE) in their baby.DesignProspective observational study from 1996 to 2010 in the UK.ResultsOf 6487 babies enrolled, 37 died (5.7 per 1000). There were 2789 (43.0%) SUDI related babies of whom, six died suddenly and unexpectedly (2.15 per 1000). Four babies were sharing a sofa at night or a bed with parent(s) who smoked or had consumed alcohol. Of the 1882 (29.0%) babies enrolled following an ALTE, five died suddenly and unexpectedly (2.66 per 1000): four unexplained and one due to infection. None occurred while sharing a sleep surface, and at least three died during the day. The remaining 1816 (28%) babies were enrolled for other reasons. Seven died suddenly and unexpectedly (3.85 per 1000), two were unexplained and none associated with bed sharing.ConclusionsThe number of SUDI deaths in babies enrolled on CONI PLUS is higher than expected from UK averages. Deaths in babies enrolled because of family history of SUDI were mostly associated with inappropriate sharing of a sleep surface at night and mostly outside the peak age range for sudden infant death. The opposite is true for those enrolled following an ALTE. The number of deaths is small but findings suggest a different mechanism for death in these two groups.

BackgroundAccidental suffocation during sleep, leading to death, has been described as due to overlay or wedging of infants, particularly in a bed-sharing situation. Bed sharing is a risk factor for sudden infant death syndrome but the mechanism of death is not clearly defined. Accidental suffocation may be one such mechanism.ObjectiveTo describe accidental suffocation deaths during sleep in New Zealand between 2002 and 2009.DesignThe New Zealand mortality database, which holds data collected by the Child Youth Mortality Review Committee and the Perinatal and Maternal Mortality Review Committee, was searched for potential deaths by accidental suffocation in infants less than 1 year of age. Deaths underwent a detailed analysis by demographic data and qualitative report.ResultsThere were 48 deaths due to accidental suffocation between 2002 and 2009 in New Zealand, equating to a rate of 0.10 deaths per 1000 live births. The most common age at death was 1 month or under (n=11, 23%). Deaths were due to overlay (n=30, 63%) or wedging (n=18, 37%) and two-thirds (n=34, 71%) were in a bed-sharing situation. A quarter of deaths (n=12, 25%) occurred in makeshift bedding arrangements, some of which were away from home.ConclusionsAccidental suffocation in bed was responsible for 48 preventable deaths. Prevention of these accidental deaths needs to focus on supporting changes in family behaviour with safety messages that are consistent, persistent and disseminated widely.

AIMTo look for changes in risk factors for sudden infant death syndrome (SIDS) after decrease and stabilisation of the SIDS rate.METHODSQuestionnaires were distributed to parents of 174 SIDS infants, dying between 1984 and 1998, and 375 age and sex matched controls in southeast Norway.RESULTSThe proportion of infants sleeping prone has decreased, along with the decrease in SIDS rate for the region during the periods studied, but over half of the SIDS victims are still found in the prone position. As the number of SIDS cases has decreased, additional risk factors have become more significant. Thus, after 1993, a significantly increased risk of SIDS is seen when the mother smokes during pregnancy. After 1993, young maternal age carries an increased risk. Maternal smoking and young maternal age are associated with each other. For SIDS victims, an increase in the number of infants found dead while co-sleeping is seen, and the age peak between 2 and 4 months and the winter peak have become less pronounced.CONCLUSIONChanges in risk factor profile following the decrease in SIDS rate in the early 1990s, as well as consistency of other factors, provides further clues to SIDS prevention and to the direction of further studies of death mechanisms.

AIMS To investigate the relation between social deprivation and causes of stillbirth and infant mortality. METHODS Stillbirths and infant deaths in 6347 enumeration districts in Wales were linked with the Townsend score of social deprivation. In 1993–98 there were 211 072 live births, 1147 stillbirths, and 1223 infant deaths. Poisson regression analysis was used to estimate the magnitude of effect for associations between the Townsend score and categories of death by age and the causes of death. The relative risk of death between most and least deprived enumeration districts was derived. RESULTS Relative risk of combined stillbirth and infant death was 1.53 (95% CI 1.35 to 1.74) in the most deprived compared with the least deprived enumeration districts. The early neonatal mortality rate was not significantly associated with deprivation. Sudden infant death syndrome showed a 307% (95% CI 197% to 456%) increase in mortality across the range of deprivation. Deaths caused by specific conditions and infection were also associated with deprivation, but there was no evidence of a significant association with deaths caused by placental abruption, intrapartum asphyxia, and prematurity. CONCLUSIONS Collaborative public health action at national and local level to target resources in deprived communities and reduce these inequalities in child health is required. Early neonatal mortality rates and deaths from intrapartum asphyxia and prematurity are not significantly associated with deprivation and may be more appropriate quality of clinical care indicators than stillbirth, perinatal, and neonatal mortality rates.

In England and Wales, the rate of sudden infant death syndrome (SIDS) has had a near eightfold decline, from 2.3 deaths per 1000 live births in 1988 to 0.3 in 2009.1 Most of this decline can be attributed to the ‘back to sleep’ campaign in 1991 which led to a 75% drop.2 From 1995, part of this fall could be attributed to the introduction of the classification of some deaths as ‘unascertained’.3 This has led to concerns being raised. In 2004, a report of a working group convened by The Royal College of Pathologists and The Royal College of Paediatrics and Child Health chaired by Baroness Helena Kennedy recommended that deaths should no longer be recorded …

AIMS—To study the association between smoking during pregnancy and sudden infant death syndrome (SIDS) using prospectively collected data, making it possible to account for a number of potential confounders. DESIGN—Prospective follow up study (n = 24 986). RESULTS—The overall rate of SIDS was 0.80 per 1000 live births (n = 20). Children of smokers had more than three times the risk of SIDS compared with children of non-smokers (OR = 3.5; 95% CI 1.4-8.7), and the risk of SIDS increased with the number of cigarettes smoked per day (p < 0.05). Adjustment for parity, alcohol, and caffeine intake during pregnancy, maternal height and weight before pregnancy, years of school, occupational status, marital status, and number of antenatal care visits did not change the results. Adjustment for mother's age marginally reduced the risk of SIDS associated with smoking (OR = 3.0; 95% CI 1.2-7.3). CONCLUSIONS—Given the prospective nature of the study, the number of deaths is small; however, if our results reflect a true association between smoking during pregnancy and SIDS, approximately 30-40% of all cases of SIDS could be avoided if all pregnant women stopped smoking in a population with 30% pregnant smokers. Our study adds to earlier evidence for an association between smoking during pregnancy and SIDS. The strengths of the study are the possibility to adjust for a number of potential confounders and the fact that information about smoking habits during pregnancy was prospectively collected.

Objective: Two recent retrospective studies independently reported typically pathogenic bacteria in normally sterile sites of infants succumbing to sudden unexpected death in infancy (SUDI). These findings suggested a proportion of unexplained SUDI might be triggered by bacteraemia. The objective was to assess these observations in the context of the pathology and epidemiology of sudden infant death syndrome (SIDS) in relation to the role of infection and inflammation as triggers of these deaths. Design: A review of the literature to identify potential risk factors for unexplained infant deaths and proposal of a theoretical model for SUDI. Results: Pathologic and epidemiological evidence suggests a hypothesis based on three factors: bacterial translocation, pathogen pattern recognition insufficiency and prenatal exposure to infection. Conclusion: We propose that sterile site infections in which common toxigenic bacteria are identified indicate a brief bacteraemic episode prior to death. This might reflect an ineffective innate response to invasive pathogens that results in reduced clearance of the bacteria. Thymomegaly observed consistently among infants diagnosed under the category of SIDS might have its origins in prenatal life, perhaps generated via in utero infection or exposure to microbial antigens which results in thymocyte priming. There is consistent evidence for an infectious aetiology in many unexplained SUDI. Future directions for research are suggested.

AIM To identify features to help paediatricians differentiate between natural and unnatural infant deaths. METHOD Clinical features of 81 children judged by criminal and family courts to have been killed by their parents were studied. Health and social service records, court documents, and records from meetings with parents, relatives, and social workers were studied. RESULTS Initially, 42 children had been certified as dying from sudden infant death syndrome (SIDS), and 29 were given another cause of natural death. In 24 families, more than one child died; 58 died before the age of 6 months and most died in the afternoon or evening. Seventy per cent had experienced unexplained illnesses; over half were admitted to hospital within the previous month, and 15 had been discharged within 24 hours of death. The mother, father, or both were responsible for death in 43, five, and two families, respectively. Most homes were disadvantaged—no regular income, receiving income support—and mothers smoked. Half the perpetrators had a history of somatising or factitious disorder. Death was usually by smothering and 43% of children had bruises, petechiae, or blood on the face. CONCLUSIONS Although certain features are indicative of unnatural infant death, some are also associated with SIDS. Despite the recent reduction in numbers of infants dying suddenly, inadequacies in the assessment of their deaths exist. Until a thorough postmortem examination is combined with evaluation of the history and circumstances of death by an experienced paediatrician, most cases of covert fatal abuse will go undetected. The term SIDS requires revision or abandonment.

The apparent prevalence of plagiocephaly has increased in recent years as indicated by referrals to paediatricians, neurosurgeons and craniofacial surgeons for advice and management.1 For the purposes of this article, we are referring to posterior deformational plagiocephaly (PDP) as shown in fig 1 and deformational brachycephaly (DB) as shown in fig 2. Synonyms used to describe PDP are shown in box 1. PDP is seen more frequently on the right side, has a male preponderance and is related to intrauterine position. Increasing foetal size may be a contributory factor. The asymmetry of PDP is frequently accentuated postnatally by the infant’s preference of sleeping on the flattened side. ### Box 1 Synonyms Figure 1 Non-synostotic occipital plagiocephaly or posterior deformational plagiocephaly (present at birth). Figure 2 Deformational brachycephaly (acquired due to supine sleeping). The problem of PDP has been increased by the “back to sleep” programme for the prevention of sudden infant death syndrome (SIDS).2 3 This has resulted in noticeable DB (fig 2) and accentuation of PDP. We were unable to find current population figures on the incidence of either PDP or DB. PDP is asymmetrical, while DB is symmetrical. PDP is present at birth, while DB is acquired as a result of a supine sleep position. Companies promoting cranial orthotic devices (CODs) are active on the internet and in the lay press, and one company had a stand at the RCPCH meeting in York in 2008. It would appear that CODs are being widely promoted and used in the USA. At least six companies and orthotists are providing a service in the UK, with some trusts providing CODs on the NHS. The most balanced and informative internet site is, in our opinion, that of Great Ormond Street Hospital.4 In an effort to inform ourselves on current practice, in 2006 we sent a …

This study aimed to assess whether previously established risk factors for sudden infant death syndrome (SIDS) are still valid now that the incidence in the Netherlands has dropped to 0.26per 1000 liveborn infants. A distinction was made between immutable and mutable risk factors. This case-control study (part of the European Concerted Action on SIDS) comprised 73 SIDS cases and 146 controls and lasted from March 1995 to September 1996. Adjustments were made for sleeping position and bedding factors by treating them as covariables. Apart from these factors, well known risk factors that remain of importance in the Netherlands are: male sex, young maternal age, twins, and low socioeconomic status. These factors are largely immutable. Other well known risk factors which might reflect attitudes to child care and could possibly be mutable are: smoking, alcohol consumption by the mother, bottle feeding, and change of babycare routine. Intervention strategies should focus on early signalling, thereby assisting parents in changing these unfavourable parenting attitudes. Information on optimal child care and extra support by public health nurses specifically aimed at families at risk could help to decrease further the incidence of SIDS in the Netherlands.

Paediatricians and others involved in the area of child protection must work together with other professionals

Background: Sudden infant death syndrome (SIDS) is a diagnosis of exclusion that may be assigned only after investigations including a forensic autopsy are performed to exclude possible organic and environmental causes of death. Israeli society is influenced by the Jewish and Islamic faiths, which permit autopsy only under selected circumstances. Against this background, we carried out a study to determine what examinations are performed to investigate unexplained infant deaths in Jerusalem, Israel. Methods: We examined hospital, Ministry of Health and Ministry of Interior records of unexplained infant deaths in the Jerusalem district from the years 1996–2003. Results: Ninety six cases were identified from all sources. Forty nine (51%) infants were brought to a hospital at or near the time of death. Studies to determine the cause of death were performed in 54% of cases for which medical records were available for review. These studies included bacterial cultures (44%), skeletal surveys (12%), computerised tomography (3%) and metabolic studies (3%). Only one forensic autopsy was performed, and in no instance was the death site examined by medical personnel. There was a high rate of retrospective review by district health physicians. The most frequently assigned cause of death was SIDS. Conclusions: : The capacity of public health officials and forensic pathologists to investigate unexplained infant deaths is strongly affected by the legal, religious and political milieu in which they work. Efforts should be made to develop socially acceptable methods of improving the quality of infant death investigations in Jerusalem.

Despite significant reductions in infant sleep-related deaths, they continue to be a leading cause of infant mortality and further reductions have proven difficult to achieve compared with the initial dramatic reductions brought about by Back to Sleep campaigns. Because night-time caregiving behaviours and infant sleep environments involve a complex interplay between environmental, biological and behavioural variables, designing effective interventions to improve sleep-related outcomes represents a significant public health challenge. Hayman and colleagues1 present data on infant suffocation deaths involving wedging or overlay in the sleep environment which occurred in New Zealand between 2002 and 2009. They examine the scenarios which resulted in sleep-related infant mortality and which may be used to refine existing paediatric recommendations. The authors claim that their data reinforce the need for ‘consistent, persistent’ safe sleep messages which are disseminated widely. However, this type of authoritative health promotion has been critiqued and other models for delivering negotiated, individualistic messages are considered to be more effective where complex behaviours are involved. With regard to infant sleep safety, message exposure and awareness of sleep-related risk factors represents only one possible reason why sleep-related risks to infants exist. Furthermore, a singular focus on message delivery inhibits the very types of conversations with healthcare providers that are necessary for parents to engage in contingency planning. In many cases, healthcare providers are not well prepared for conversations with parents who cannot or will not comply with recommended practices. Situations which require contingency planning and challenge parents to know how to transfer recommendations to different sleeping arrangements than the one …

Abnormal fetal and infant growth have increasingly been correlated with adult onset cardiovascular disease. To date, there is little known about the lipid fatty acid profiles in infant cardiovascular tissue. Therefore, we analysed total lipid fatty acids from thoracic and abdominal aorta intima and media from 24 normally grown sudden infant death syndrome cases. Aorta from small for gestational age (n = 2), failure to thrive from birth (n = 3), and premature (n = 1) infants were also examined. Dihomo-gamma-linolenic acid (C20:3n-6) and oleic acid (C18:1n-9) concentrations were significantly lower in the thoracic than in the abdominal aorta. Similar dietary related differences were found in the subgroup (n = 15) of infants fed on formula milks. Both abdominal and thoracic intimal arachidonic (C20:4n-6) to dihomo-gamma-linolenic acid ratios were greater in the infants with retarded growth after birth than in their normally grown counterparts. Growth restriction in infancy might disrupt the normal accretion of vascular endothelial polyunsaturated fatty acids.

Previous studies of the abnormal physical properties of lung surfactant derived from infants experiencing prolonged expiratory apnoea, or who have died of sudden infant death syndrome (SIDS), have led to a search for the agent responsible. Bronchoalveolar lavage (BAL) has been performed upon 12 infants under 12 months at necropsy and the rinsings analysed for up to 26 bile acids using high performance liquid chromatography, which requires nanomolar quantities. They were also analysed for simultaneously retrieved phospholipid and proteolipid—a minor component of lung surfactant—as markers of lavage eYciency. Total bile acid (TBA) was found to be higher in six SIDS cases, reaching a mean (SE) 8.54 (2.24) µmol/l in the BAL fluid compared with 4.66 (1.47) µmol/l in the six controls of similar age.When related to the concomitant surfactant yield, the TBA/ proteolipid and TBA/phospholipid ratios both showed highly significant diVerences between index lungs and controls, providing another postmortem marker of SIDS with potential for development as a test of risk. Since the bile:phospholipid ratio determines whether phospholipase A2 synthesises or hydrolyses phospholipid, the raised TBA/phospholipid ratio could be highly significant, causing this enzyme to function more like its role in the gut than in the lung. (Arch Dis Child 1997;77:120‐123)