Higher Risk Of Sudden Infant Death Syndrome Research Articles

Cerebrospinal Fluid Histamine Levels in Healthy Children and Potential Implication for SIDS: Observational Study in a French Tertiary Care Hospital.

ObjectiveA defect of the waking systems could constitute a factor of vulnerability for sudden infant death syndrome (SIDS). A decrease in orexin levels, which promotes wakefulness and activates histaminergic neurons (another hypothalamic wake-promoting system) has already been demonstrated between 2 and 6 months. This work aims to study the levels of histamine (HA), tele-methylhistamine (t-MeHA), its direct metabolite, and t-MeHA/HA ratio in the cerebrospinal fluid (CSF) of healthy children, to evaluate the maturation of the histaminergic system and its possible involvement in SIDS.MethodsSeventy Eight French children between 0 and 20 years (48.7% boys) were included, all of whom had a clinical indication for lumbar puncture, but subsequently found to be normal. Measurements of HA and t-MeHA in CSF were performed by reverse phase liquid chromatography coupled to mass spectrometry detection. Statistical analyses were performed using Spearman correlations and Non-parametric pairwise ranking tests.ResultsA negative correlation was found between age and CSF HA (r = −0.44, p < 10−4) and t-MeHA (r = −0.70, p < 10−4) levels. In pairwise comparisons, no difference in CSF HA and t-MeHA levels was observed between youngest age groups (i.e., 0–2 mo vs. 3–6 mo), but CSF HA and t-MeHA levels were significantly lower in older children (i.e., >6 mo vs. 0–6 mo). The CSF HA decrease with age was only observed in boys, who also presented global lower CSF HA levels than girls.ConclusionCSF HA and t-MeHA levels decrease with age in boys, and global levels are lower in boys than in girls. These results reveal changes in histaminergic transmission and metabolism during maturation. Whether lower CSF histamine values in boys compared to girls could contribute to their higher risk of SIDS warrants further research.

Ambient Air Pollution and Sudden Infant Death Syndrome in Korea: A Time-Stratified Case-Crossover Study.

Sudden infant death syndrome (SIDS) is an occasional cause of unexpected mortality in infancy. While various etiological factors have been hypothesized, air pollution has been consistently presented as an environmental factor. In this study, we aimed to estimate the risk of SIDS in relation to exposure to air pollution and the effects of its modifying factors. A mortality dataset with supplementary infant mortality survey data from Statistics Korea was used and combined the concentration of ambient air pollution data from AirKorea based on the date of death and residential addresses of the SIDS cases. Odds ratios (ORs) were estimated according to birthweight, gestational age, maternal age, and infant age using a time-stratified case-crossover study design. The risk of exposure to particulate matter of less than 10 μm in diameter (PM10), nitrogen dioxide (NO2), carbon monoxide (CO), and sulfur dioxide was estimated. The number of deaths due to SIDS was 454 (253 males and 201 females). The OR per 27.8 µg/m3 increment of PM10 was 1.14 (95% confidence interval [CI]: 1.03–1.25) and that per 215.8 ppb of CO was 1.20 (95% CI: 1.03–1.40) in all infants. In females, an increase in NO2 and CO levels was associated with a higher risk of SIDS in low-birthweight and preterm infants. The OR per 15.7 ppb increment in NO2 was highest among preterm infants, with a value of 5.12 (95% CI: 1.27–20.63), and low-birthweight individuals, with a value of 4.11 (95% CI: 1.74–9.72), at a moving average of 0 to 3 days. In males, however, no significant association was found. In the present study, exposure to air pollution was associated with an increased risk of SIDS. This association was more evident in susceptible infants with a low-birthweight or in cases of preterm birth.

Breastfeeding in Sicily Region (Southern Italy): analysis of prevalence, of contextual inequalities, and of other associated risk factors

to describe the prevalence of breastfeeding in Sicily Region (Southern Italy) and to analyze the socioeconomic status and other major risk factors on the attitudes towards exclusive breastfeeding. information on the practice of breastfeeding in Sicily have been collected from a Regional survey on Sudden Infant Death Syndrome (SIDS). An index of socioeconomic position was created by using data from the 2011 Census of the Italian National Institute of Statistics. in May 2015, a questionnaire was distributed to all mothers accessing to immunization services in Sicily for the first vaccination of their children. Two hundred seventy-three (273) vaccination centres have been involved, and 2,692 questionnaires were administered. five socio-economic levels were identified and, for each of them, the prevalence of breastfeeding and the risk factors for nonadherence to exclusivebreastfeeding were described. the prevalence of exclusive breastfeeding was 30.6%, unevenly distributed in the region, being the lowest in the Province of Messina (21.4%). Nonadherence to exclusive breastfeeding was associated with the disadvantage of the low context culture (χ2: 14.9), and was more common in the areas with higher socioeconomic deprivation index (odds ratio - OR: 1.81). Among other determinants investigated, being premature was a risk factor for not being breastfed (OR: 1.59). the study confirms a low prevalence of breastfeeding in Sicily and its association with the socioeconomic level, being lower among women living in higher disadvantage areas. Moreover, this study confirms the association with co-sleeping practices (rooming-in and bed-sharing) for preterm babies. However, mother-child bed-sharing is not a guarantee for a successful breastfeeding, indeed being associated with a higher risk of SIDS. Finally, the study suggests the need for appropriate interventions focusing on specific high-risk groups.

Factors influencing maternal decision-making for the infant sleep environment in families at higher risk of SIDS: a qualitative study

ObjectiveQualitative interviews with mothers of babies at higher risk of sudden infant death syndrome (SIDS) were carried out to understand their views and decision-making process on the infant sleep environment...

Undiagnosed metabolic dysfunction and sudden infant death syndrome--a case-control study.

Decades of research has yielded few clues about causes of sudden infant death syndrome (SIDS). While some studies have shown a link to inborn errors of metabolism (IEMs), few have examined the link in a large population-based sample. This population-based case-control study assessed the association between undiagnosed IEMs and SIDS. Children born in California during 2005-08 who died from SIDS were obtained from death records and linked to the newborn screening, birth certificate, and hospital discharge databases. Individuals with known chromosomal and neural tube defects, genetic disorders, and non-singleton births were excluded. Five controls were matched to each case on tandem mass spectrometry testing date and lab code. Rates of undiagnosed IEMs were compared between cases and controls using conditional logistic regression adjusting for known confounding factors. After adjusting for known confounding factors, SIDS cases had similar risk of having IEMs as controls (adjusted hazard ratio [HR] 1.3, 95% confidence interval [CI] 0.3, 5.5). Infants who were male, Black, and born preterm had higher risk of SIDS with the highest risk observed for those born preterm [adjusted HR = 1.7, 95% CI 1.3, 2.2]. Younger maternal age at delivery, mother being born in the US, parity after current birth >3, and delayed prenatal care were also significantly associated with higher risk of SIDS. While many maternal and infant factors are associated with an increased risk of SIDS, there is no evidence that undiagnosed IEMs are associated with increased risk.

Sudden unexpected death in infancy: a historical perspective.

Epidemiological, developmental and pathological research over the last 40 years has done much to unravel the enigma of sudden unexpected death in infancy (SUDI) and sudden infant death syndrome (SIDS) that has afflicted the human condition for millennia. Modifications in infant care practices based on the avoidance of risk factors identified from a consistent epidemiological profile across time and multiple locations have resulted in dramatic reductions in the incidence of SUDI and SIDS in particular. The definition of SIDS (or unexplained SUDI) has been continually refined allowing enhanced multidisciplinary research, results of which can be more reliably compared between investigators. These latter expanded definitions mandating death scene investigations, evaluation of the circumstances of death and more comprehensive autopsies including additional ancillary testing have illuminated the importance of life-threatening sleep environments. The triple-risk hypothesis for SIDS has been increasingly validated and formulates an inextricable relationship between an infant's state of development, underlying pathological vulnerability and an unsafe sleep environment for sudden infant death to occur. Today, the major risk factors for SUDI are maternal smoking and bed sharing, and the challenge is to implement effective strategies that will reduce the exposure to such risks as was done with prone sleeping position. The challenges ahead include development of clinical methods and/or laboratory testing that will accurately identify which infants are at particularly high risk of SIDS but also means by which their deaths can be prevented.

Apparent Life-Threatening Events

Apparent Life-Threatening Events

Sudden Infant Death Syndrome: An Update

Sudden Infant Death Syndrome: An Update

Maternal smoking impairs arousal patterns in sleeping infants.

Impairment of the arousal process from sleep is thought to be involved in the pathogenesis of sudden infant death syndrome (SIDS). We hypothesized that a greater propensity for cortical arousal in the prone position may, in a normal infant, be a protective mechanism to promote complete arousal in a vulnerable sleeping position, a protection that is absent in SIDS victims. We aimed to examine the arousal process in a group of infants exposed to maternal smoking, who are thus at higher risk for SIDS. Twelve healthy, full-term infants born to smoking mothers were studied using daytime polysomnography at 2 to 4 weeks, 2 to 3 months and 5 to 6 months postnatal age. Data were compared with 13 healthy infants born to nonsmoking mothers. Arousal was induced by pulsatile air-jet stimulation to the nostrils during active and quiet sleep, in both supine and prone positions. For each stimulus, physiologic and electroencephalogram changes were visually assessed and arousal responses were classified as sub-cortical activation or cortical arousal. In smoke-exposed infants, the progression from sub-cortical activation to cortical arousal was depressed at 2 to 4 weeks and 5 to 6 months. There was no effect of maternal smoking observed at 2 to 3 months; however, a significant dose-dependent relationship between cortical activation proportions and urinary cotinine levels was present in both supine and prone positions. We have shown that maternal smoking is associated with impaired arousal processes to trigeminal stimulation that may increase the risk for SIDS. This further highlights the importance of public education of the risks of maternal smoking.

Hazardous cosleeping environments and risk factors amenable to change: case-control study of SIDS in south west England

Objectives To investigate the factors associated with sudden infant death syndrome (SIDS) from birth to age 2 years, whether recent advice has been followed, whether any new risk factors have...

Infant Sleep Location: Associated Maternal and Infant Characteristics with Sudden Infant Death Syndrome Prevention Recommendations

To identify factors associated with infant sleep location. Demographic information and infant care practices were assessed for 708 mothers of infants ages 0 to 8 months at Women, Infants and Children centers. Generalized linear latent mixed models were constructed for the outcome, sleeping arrangement last night (room-sharing without bed-sharing versus bed-sharing, and room-sharing without bed-sharing versus sleeping in separate rooms). Two-thirds of the mothers were African-American. A total of 48.6% mothers room-shared without bed-sharing, 32.5% bed-shared, and 18.9% slept in separate rooms. Compared with infants who slept in separate rooms, infants who room-shared without bed-sharing were more likely to be Hispanic (odds ratio [OR], 2.58, 95% CI 1.11-5.98) and younger (3.66- and 1.74-times more likely for infants 0-1 month old and 2-3 months old, respectively, as compared with older infants). Compared with infants who bed-shared, infants who room-shared without bed-sharing were more likely to be 0 to 1 month old (OR, 1.57; 95% CI, 1.05-2.35) and less likely to be African-American (OR, 0.43; 95% CI, 0.26-0.70) or have a teenage mother (OR, 0.37; 95% CI, 0.23-0.58). Approximately one-third of mothers and infants bed-share, despite increased risk of sudden infant death syndrome (SIDS). The factors associated with bed-sharing are also associated with SIDS, likely rendering infants with these characteristics at high risk for SIDS.

Contribution of Long-QT Syndrome Genes to Sudden Infant Death Syndrome

Sudden infant death syndrome (SIDS) is defined as unexplained and unexpected death within the first year of life, without any known preexisting inciting conditions or obvious cause of death on postmortem examination. It remains the most common cause of infant death (excluding neonatal period) in developed countries, occurring in ≈0.03% to 0.1% of live-born infants in the United States.1 Article p 361 The precise mechanisms for SIDS, or “crib death,” are not known, although multiple hypotheses have been proposed over the years, including abnormal brainstem respiratory control of arousal, dysautonomia, and malignant cardiac bradyarrhythmias or tachyarrhythmias.2–4 Genetic, developmental, and environmental risk factors for SIDS have been identified, such as premature birth, multiple gestations, being the sibling of a SIDS victim, maternal illicit drug use, prone sleeping position or bed sharing, and history of apnea/bradycardia or “near-miss SIDS” episodes.3–5 Investigators have suggested respiratory control regulatory abnormalities, neurological developmental defects, and cardiac rhythm disorders, including QT prolongation and ventricular arrhythmias, as underpinnings of SIDS. Supporting these various hypotheses are common autopsy findings such as petechial hemorrhages, pulmonary congestion, and developmental defects in the brainstem and neurotransmitters.4,5 Myriad diagnostic studies have been used for potential risk stratification of infants thought to be at higher risk for SIDS and have included electroencephalogram, pulse oximetry, 12-lead ECG, home apnea monitoring, and infant polysomnography sleep studies. The National Institutes of Health and the American Academy of Pediatrics have actively promoted the supine sleeping position for healthy term infants, and pediatricians have educated parents to put infants to sleep in the supine position. This simple recommendation has, at least in part, contributed to a significant reduction in the incidence of SIDS.6 Death from cardiac causes is uncommon in infancy and is most often the result of cardiac electrical diseases such as the …

Infant temperament characteristics related to sudden infant death syndrome and its risk factors

Three major components have been repeatedly implicated for the origin(s) of sudden infant death syndrome (SIDS): system, minor sickness and surroundings. All these factors also frame infant temperament, and therefore it seems logical to suppose that the babies who either succumb to or are at risk of SIDS may present with certain behavioural features. The infants who have died of SIDS moved less when lying awake in the crib, during feeding and during nail cutting; less often turned their head away and looked for their mother when held by a new person; were more frequently reported to show an extreme response (either almost never protested or almost always objected) when approached by someone other than main caregiver; and exhibited extreme behavioural patterns when the infant’s vocalising on waking up was studied. The infants who died of SIDS had lower activity scores. An unfavourable microenvironment can increase the risk of SIDS, and the babies facing less developmental stimulation had a more negative mood and were less distractible; less organised infants presented with a more negative mood, less distractible behaviour, lower rhythmicity, lower persistence and lower adaptability. The infants born to smoking mothers who are at risk of SIDS had more intensive reactions. The low‐birth‐weight infants who are at high risk of SIDS were more withdrawing and less adaptable. Infant–parent(s) bed sharing may increase the risk of SIDS, and solitary sleeping infants had a more positive mood and were more persistent. Use of a pacifier may be protective against SIDS, and pacifier users presented with higher rhythmicity. Prone sleep is known to increase the risk of SIDS, and the lowest persistence was a feature of those babies who were usually put to sleep supine and found prone. Infants who snored and/or had noisy breathing in sleep were characterised by more negative mood. Infants with signs of repetitive regurgitation were less distractible.

Sleep Biological Rhythms in Normal Infants and those at High Risk for SIDS

The focus of this study was on daytime and nighttime sleep and wakefulness during the peak age for Sudden Infant Death Syndrome (SIDS), two to four months, to determine whether there are differences between at‐risk for SIDS (R) and control (C) infants. Such differences may provide insight on the frequent occurrence of SIDS in the early morning hours, when most babies are asleep. This is the only study in which R and C infants were continuously monitored for long periods of time (24–48 h) and then followed and recorded at monthly intervals until the age of 4–6 months. Data analyses indicate that ultradian REM/NREM cyclicity becomes stabilized into a regular pattern at three months of age. Infants at this age convert from a polyphasic sleep/wakefulness pattern to a circadian one. Among the changes that occur is a lengthening of short sleep periods that consolidate at night and wake periods that consolidate in the daytime. The most striking effects are related to sleep state and vary according to age and sex. The lengthening of single sleep and wakeful periods is coupled with the maturation of the brain. The development of the central nervous system facilitates the synchronization of sleeping patterns with external light input and social entrainment. One or more biological clocks or oscillators may be responsible for these REM/NREM patterns and circadian cycles. These differences during the early morning hours, when the occurrence of SIDS peaks, may have important implications for understanding the pathophysiological mechanism of SIDS.

Stable Prevalence but Changing Risk Factors for Sudden Infant Death Syndrome in Child Care Settings in 2001

A total of 20% of sudden infant death syndrome (SIDS) cases in the 1990s occurred in child care settings. This is much higher than the 8% expected from Census Bureau data. Factors that were associated with child care SIDS included older age; white race; older, more educated mothers; and unaccustomed prone position. Since these findings, much emphasis has been placed on promoting a safe sleep environment in child care. The objectives of this study were to determine the proportion of SIDS occurring in child care in 2001 and to assess risk factors for SIDS in child care. We conducted a retrospective review of all SIDS deaths that occurred in 2001 in 13 US states. Information regarding demographics, SIDS risk factors, and child care arrangements were collected and analyzed. Deaths that occurred in child care were compared with deaths that occurred during parental care. Of 480 deaths, 79 (16.5%) occurred in child care settings. Of these child care deaths, 36.7% occurred in family child care homes, 17.7% occurred in child care centers, 21.3% occurred in relative care, and 17.7% occurred with a nanny/babysitter at home. Infants in child care were more likely to be older and to die between the hours of 8 am and 4 pm and less likely to be exposed to secondhand smoke. There was no difference in usual, found, or placed sleep position between child care and home deaths. Approximately one half of the infants who died of SIDS in both settings were found prone, and 20% of deaths in both settings were among infants who were unaccustomed to prone sleep. The proportion of SIDS deaths in child care has declined slightly but still remains high at 16.5%. Infants in child care are no more likely to be placed or found prone and no more likely to be on an unsafe sleep surface. Educational efforts with child care providers have been effective and should be expanded to unregulated child care providers. In addition, there may be other, yet-unidentified factors in child care that place infants in those settings at higher risk for SIDS.

Sudden infant death syndrome among twin births: United States, 1995-1998.

To compare the incidence and risk factors for sudden infant death syndrome (SIDS) in twin and singleton births and to estimate the concordance of SIDS in twins. A cohort analysis using the National Center for Health Statistics Linked Birth and Infant Death files (1995-1998). Twins had higher SIDS rate (1.3/1000 live births) compared to singletons (0.7/1000 live births), relative risk: 1.9, 95% confidence interval: 1.68, 2.01. Male and small- for-gestational age infants as well as infants of black, unmarried, and smoking mothers were at increased risk for SIDS in both twins and singletons. Placental abnormalities also were associated with SIDS in singletons and twins, although this association failed to achieve statistical significance in twins. There is a higher rate of SIDS in the second twin after a first twin SIDS. Twins are at higher risk of SIDS than are singletons. Overall, the epidemiology of SIDS in twins is quite similar to that seen in singletons.

Infant sleeping position and the risk of sudden infant death syndrome in California, 1997-2000.

To assess the association between infant sleeping position and risk of sudden infant death syndrome (SIDS) in an ethnically diverse US population, the authors conducted a population-based case-control study in 11 counties in California from May 1997 through April 2000. The authors conducted in-person interviews with the mothers of 185 SIDS cases and 312 randomly selected race/ethnicity- and age-matched controls to collect information on sleeping positions. Infants who had last been put down to sleep in the prone or side position were at greater risk of SIDS than were infants who had last been put down on their backs (adjusted odds ratio (AOR) = 2.6 (95% confidence interval (CI): 1.5, 4.5) and AOR = 2.0 (95% CI: 1.2, 3.4) for the prone and side positions, respectively). The risk of SIDS was especially high for an unstable side position in which an infant was placed on its side and found prone (AOR = 8.7, 95% CI: 3.3, 22.7). Infants who were usually placed on their backs to sleep but had last been put down in the prone or side position (an unaccustomed position) had a significantly high risk of SIDS (AOR = 8.2 (95% CI: 2.6, 26.0) and AOR = 6.9 (95% CI: 2.3, 20.6) for the prone and side positions, respectively). Infants placed in an unaccustomed prone or side sleeping position had a higher risk of SIDS than infants who were always placed prone or on the side.

Sudden infant deaths: arousal as a survival mechanism

The mechanisms responsible for sudden infant death syndrome (SIDS) are still largely unknown. To explain what factors contribute to the deaths, we suggest a model: the ‘3 S model for SIDS’ that includes ‘sicknesses’, ‘stages of development’ and ‘surroundings’: (1) ‘sicknesses’ refers to infectious diseases or other medical condition. (2) ‘Stages of development’ relates to the maturation of vital systems including respiratory, neurovegetative or sleep-wake behavioral controls. (3) ‘Surroundings’ refers to environmental conditions that enhance the deficiency of cardiorespiratory, vegetative and/or arousal controls. Such conditions were identified by epidemiological studies and include the following main risk factors: the prone body position during sleep, high environmental temperature, maternal smoking or sleep deprivation. An infant could be at higher risk for SIDS because of a deficiency in breathing and cardiac autonomic controls during sleep, inducing repeated episodes of hypoxia and hypoxemia. The risk is increased when the infant has a lower propensity to arouse from sleep and so, to autoresuscitate. The accident has a greater probability to occur when an infection, or an unfavorable environmental factor aggravates the immature cardiorespiratory and sleep/wake behaviors of the infant. The clinical findings could be related to the changes reported in the brainstems of SIDS victims.

Sudden infant death syndrome, bedsharing, parental weight, and age at death.

To assess the role of parental bedsharing in sudden infant death syndrome (SIDS)-like deaths, this study examines the hypothesis that, compared with other SIDS cases, the age distribution of deaths associated with bedsharing should be lower in younger, less vigorous infants. For 84 SIDS cases in Cleveland, Ohio, 1992 to 1996, age at death, maternal weight, and other risk factors for SIDS were compared for cases grouped according to bedsharing status. Mean ages at death were 9.1 weeks for 30 bedsharing and 12.7 for 54 nonbedsharing cases, counting 10 with missing information as nonbedsharing. Mean pregravid weights of bedsharing mothers exceeded those of nonbedsharing mothers (84.1 vs 67.0 kg). Mean ages at death for nonbedsharing infants, bedsharing infants of smaller mothers, and bedsharing infants of larger mothers were 12.7, 10.3, and 7.6 weeks, respectively. Large maternal size did not affect age at death in the absence of bedsharing. By demonstrating that among an urban population at high risk for SIDS, bedsharing is strongly associated with a younger age at death, independent of any other factors, this study provides evidence of a relationship between some SIDS-like deaths and parent-infant bedsharing, particularly if the parent is large.

Distribution of prenatal and postnatal risk factors for sudden infant death in Budapest

Objective - To study the distribution of prenatal and postnatal risk factors for sudden infant death syndrome (SIDS). Design - A questionnaire-based survey for SIDS risk factors; family interviews were performed among the parents of SIDS victims and symptom-free infants. Setting - The survey was conducted in paediatric primary health care units in Budapest, Hungary in the period 1996 to 1998. Subject - Eighteen SIDS cases and 74 symptom-free healthy infants aged 7-365 days were investigated. Main outcome measures - Occurrence of risk factors and impact of social environment were analysed using conditional logistic regression. Results - In this study, the classic risk factors of small birth weight, maternal smoking, bottle-feeding did not reflect differences between the investigated groups. The prone position did not demonstrate a difference between SIDS cases and controls (p =0.86). Short intervals between pregnancies (OR =4.8, CI =1.2?19.9, p =0.025) and social disadvantage (OR =6.7, CI =1.3?35.7, p =0.015) indicated significant differences between SIDS cases and controls. Conclusion ? The outcome of our survey shows that infants from a lower social and economic environment may be at higher risk for SIDS.