DTP vaccine and infant sudden death syndrome. Meta-analysis

BACKGROUND: At the beginning of 1994, five cases of sudden infant death syndrome after DTP immunization appeared in Spain. In order to study a causal relationship a meta-analysis of the different studies that assess this possibility has been conducted. METHODS: The selection criteria was epidemiological study, case-control or cohort, assessing risk of sudden infant death syndrome in immunized versus non-immunized infants or risk of sudden infant death syndrome in recently immunized infants versus immunized infants beyond 30 days. Pooled risk ratios were calculated from adjusted risk ratios, when available, of the different studies, by a meta-analysis according the method described by Greenland. RESULTS: One cohort and four case-control studies were selected. Pooled risk ratio for immunized versus non-immunized infants was 0.67 (95% CI = 0.60-0.75). When comparing risk of sudden death syndrome in up to 30 days immunized infants versus more than 30 days immunized infants, the pooled risk ratio was 1.00 (95% CI = 0.84-1.20). CONCLUSIONS: DTP-immunization does not seem to increase the risk of sudden infant death syndrome. The risk of sudden infant death syndrome is not greater in the first thirty days following immunization. These data indicate a lack of association between DTP immunization and sudden infant death syndrome.     

Activation of p70 S6 protein kinase is necessary for angiotensin II-induced hypertrophy in neonatal rat cardiac myocytes

Infants with mandibular hypoplasia are at risk of sudden death from cardiorespiratory arrest secondary to upper airway obstruction. To evaluate diagnostic difficulties that may occur at autopsy in such infants, the autopsy files at the Adelaide Children's Hospital (ACH) for 36 years, 1959 to 1994, were reviewed. Eight cases were identified (age range, 2 days to 10 months; mean age, 2.2 months; male/female ratio, 5:3). In all cases, death was considered most likely due to airway obstruction related to mandibular hypoplasia or its treatment. Although death occurred in the hospital in five cases, one infant suddenly collapsed at home while feeding and died, and two infants were unexpectedly found dead in their cribs at home. Three infants had defined genetic syndromes. Although all the infants had histories of antemortem airway obstruction, one infant had normal oxygen saturation studies before hospital discharge, and one infant had a tracheostomy. Acute bronchopneumonia was an exacerbating factor in one case. Assessment of mandibular size is important in any infant who dies unexpectedly; and if hypoplasia is found, careful review of the clinical details for evidence of airway obstruction is necessary to help distinguish these cases from sudden infant death syndrome (SIDS). Sudden death may, however, occur in infants with mandibular hypoplasia in spite of apparent clinical stability before death with no significant recent episodes of oxygen desaturation.     

Biologic pollution in infant bedding in New Zealand: high allergen exposure during a vulnerable period

BACKGROUND: High exposure to house dust mite and cat allergens in early life predisposes to allergic sensitization and to the development and persistence of asthma. Prevalence and severity of asthma are high in New Zealand. OBJECTIVE: The objective of this study was to determine the concentrations of Der p 1 and Fel d 1 in infant bedding in Wellington, New Zealand. METHODS: Infants were visited at home at a mean age of 11 weeks and again at 15 months. The concentration (microgram/g fine dust) and content (microgram/m2) of Der p 1 (154 infants) and Fel d 1 (75 infants) were measured in dust samples taken from each infant's bed. RESULTS: At 11 weeks, geometric mean (95% confidence intervals) Der p 1 levels were 18.3 micrograms/g (13.8 to 24.1) and 3.51 micrograms/m2 (2.4 to 5.2). By 15 months, Der p 1 had risen significantly to 44.0 micrograms/g (35.0 to 55. 3) and 49.0 micrograms/m2 (36.0 to 66.8). Bedding that included a sheepskin was used by a third of the infants and contained higher concentrations (microgram/g) and content (microgram/m2) of Der p 1 than beds without sheepskins. Cat ownership was the major determinant of Fel d 1 levels, with 48% of infants living with cats. At the first visit, the mean concentration of Fel d 1 in bedding was 44.6 micrograms/g (23.5 to 84.9) for houses with cats and 3.0 micrograms/g (2.1 to 4.3) for those without cats, remaining essentially unchanged at the second visit. When expressed as micrograms per square meter, there was a significant increase between visits, from 8.1 (3.9 to 16. 6) to 39.6 (19.9 to 78.5) in the cat-inclusive households. CONCLUSIONS: Extremely high levels of house dust mite allergen have been found in these infants' environments, which, together with the high levels of cat allergen in almost half who kept cats, are likely to be a major determinant of asthma prevalence and severity in New Zealand.     

Central nervous system damage as a possible component of unexpected deaths in infancy

A longitudinal study of 1553 infants, designed to provide early indicators of gross developmental problems by using a behavioral assessment scale, included 12 infants who later died suddenly and unexpectedly. In a retrospective examination of neonatal records, considerable evidence of central nervous system damage was found. Anoxic conditions and even possible seizure activity were implicated. Abnormalities of muscle tonus, skin color and cry were found, together with some visual problems. These findings on behavioral assessment in the neonatal period appear to identify a population which is at greater risk of sudden death in infancy. The need for oxygen therapy as a high-risk indicator of sudden unexpected death has been reported in a previous study and is further substantiated by the present findings: they are also compatible with thos of Naeye (1973), who found long-term hypoxic conditions in autopsy studies on the sudden infant death syndrome. It is suggested that the possibility of central nervous system involvement in the aetiology of the sudden infant death syndrome should be more thoroughly investigated.     

Gender and the sudden infant death syndrome. New Zealand Cot Death Study Group

A nationwide case-control study compared the prevalence and magnitude of risk factors for sudden infant death syndrome (SIDS) in male and female infants. The risk factors of SIDS and their magnitude for males and females are very similar. After adjustment for potential confounders male infants had a 1.42-fold (95% CI = 1.04, 1.94) increased risk of SIDS compared with females. Risk factors identified in most epidemiological studies are not the reason for the increased SIDS mortality seen in male infants.     

Religion's role in adjustment to a negative life event: Coping with the loss of a child.

Parents (N?=?124) who had lost an infant to sudden infant death syndrome were interviewed 3 wks and 18 mo postloss. Two components of religion (religious participation and religious importance) were assessed, and their relations with 3 coping-process variables (perceived social support, cognitive processing of the loss, and finding meaning in the death) were examined. Greater religious participation was related to increased perception of social support and greater meaning found in the loss. Importance of religion was positively related to cognitive processing and finding meaning in the death. Furthermore, through these coping-process variables, religious participation and importance were indirectly related to greater well-being and less distress among parents 18 mo after their infants' deaths. Results suggest that further study of the social and cognitive aspects of religion would be profitable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Travel and changes in routine do not increase the risk of sudden infant death syndrome

We investigated the relationship between travel and changes in routine and the sudden infant death syndrome (SIDS) among 485 SIDS cases compared with 1800 randomly selected control infants. There was no increased risk of SIDS with travel. Special events, such as christenings, were not associated with an increased risk of SIDS. However, visits to and by friends or relatives were associated with a significantly reduced risk of SIDS after controlling for potential confounders (odds ratios = 0.70; 95% confidence interval = 0.52, 0.96). These findings may indicate less social support in SIDS cases.     

A record-linkage study on risk factors for cause-specific infant mortality

Infant death certificates were linked with birth certificates for infants born to residents of Tohoku, Tokai and Kyushu regions in 1989 (n = 409, 679, or about one-third of all births in Japan), to examine the effects of variables, as reported on birth certificates, on cause-specific infant mortality. "Certain conditions originating in the perinatal period" and "congenital anomalies" accounted for nearly 90 percent of neonatal deaths, while "congenital anomalies", "injuries and poisoning" and "sudden infant death" were responsible for about 65 percent of postneonatal deaths. Mortality rates for almost all causes of infant deaths, except injuries and poisonings, increased as birth weight decreased not only in the neonatal period but also in the postneonatal period. This suggests that low birth weight places some infants at higher risk of death, and conditions that lead to low birth weight independently contribute to the risk of infant death. Cox's proportional hazards linear model was used to assess the effects of variables on infant mortalities by causes of death. An extremely strong birth weight effect was noted for "certain conditions originating in the perinatal period" and "congenital anomalies". Being a male infant and late order of birth in multiparity were other risk factors for deaths from "congenital anomalies", while being a male infant, resident of Tohoku region and maternal stillbirth experience related to deaths from "certain conditions originating in the perinatal period". Elevated risks of sudden infant death syndrome (SIDS), of which mortality rate in Japan was considerably lower than those in most developed Western countries, i.e. 0.23 per 1,000 live births in 1989, were associated with low birth weight, being a male infant, low maternal age, late order of birth in multiparity and illegitimacy. Low maternal age, late order of birth in multiparity and illegitimacy, also, related significantly to increased risk of infant deaths for "injuries and poisoning". These results suggest the independent contributions of socioeconomic factors to infant mortality, especially postneonatal mortality, from SIDS, "injuries and poisonings".     

Fetal hemoglobin levels in sudden infant death syndrome

OBJECTIVE: The aim of this study was to determine and compare fetal hemoglobin levels from infants dying of the sudden infant death syndrome (SIDS) with aged-matched control infants dying of other causes. Similar previous studies have reported both elevated and normal levels of fetal hemoglobin in whole blood samples from infants dying of SIDS. DESIGN: Triton-acid-urea gel electrophoresis and densitometry were used to determine fetal hemoglobin levels in postmortem whole blood samples from infants dying of SIDS and from appropriately age-matched control infants. Whole blood samples were analyzed blindly and matched for postgestational age. Infant ages at death ranged from birth to less than 1 year. MAIN OUTCOME MEASURES: Fetal hemoglobin in whole blood from infants dying of SIDS and control infants. RESULTS: During the period of postnatal development most associated with SIDS cases (2 to 6 months after birth), fetal hemoglobin levels were found to be significantly elevated in postmortem whole blood samples from SIDS infants compared with gestational age-matched control infants dying of causes other than SIDS. CONCLUSION: We conclude that levels of fetal hemoglobin are elevated in postmortem whole blood of SIDS infants compared with controls. Furthermore, the apparent conflict in the literature regarding fetal hemoglobin levels in SIDS infants and controls is most likely due to variability in the control data of some studies.     

Ethnic differences in the sudden infant death syndrome: what we can learn from immigrants to the UK

AIMS: To compare the effect of potential maternal and birth factors on rates of sudden infant death syndrome (SIDS) within and between infants born to mothers of different ethnic groups. METHODS: Routinely collected obstetric, child health data relating to 39,101 residents of three East London Districts born in 1989-1990 were obtained. These were matched with 312 death registration records to validate death and add registered cause of death. Mortality rates were calculated in the usual way, and using life-table methods. RESULTS: These related to six ethnic groups, the largest of which were Anglo-European and Bangladeshi. Low birth-weight was the only factor associated with a greater risk of SIDS in all ethnic groups. Maternal smoking was uncommon amongst all Asian groups and African mothers, and rates of SIDS were uniformly low amongst non-smokers in all ethnic groups except Pakistanis. Adjustment for maternal age, parity, gestational age and birthweight would widen the differences between risk of SIDS observed between Anglo-Europeans and Bangladeshi infants. CONCLUSIONS: The study has demonstrated that local data is more timely and of greater detail than that available nationally. Of the risk factors considered, smoking reported during pregnancy is the most commonly encountered and is particularly associated with deaths attributed to SIDS.     

Cerebral white matter lesions in sudden infant death syndrome

In 21.6% of infants who died of sudden infant death syndrome, the cerebral white matter showed areas of leukomalacia. Of those infants with congenital heart disease, 24.8% had lesions, whereas 4.4% of infants who died from known acute causes had lesions. The sites of the cerebral white matter lesions, subcortical or periventricular, seem to be related to the age of the infant.     

Sudden infant death syndrome: risk factor profiles for distinct subgroups

The authors investigated risk profiles of sudden infant death syndrome (SIDS) as a function of age at death. A case-control study carried out in the Tyrol region of Austria enrolled 99 infants who died of SIDS between 1984 and 1994 and 136 randomly selected controls. Early and late SIDS (< 120 days of age vs. > or = 120 days) were defined according to the clear-cut bimodal age-at-death distribution. Inadequate antenatal care, low parental social and educational level, and the prone sleeping position were risk conditions that applied to both early and late SIDS. A marked seasonal variation (winter preponderance) was the most outstanding feature of late SIDS. A gestational age of < 37 weeks (odds ratio (OR) = 8.4, 95% confidence interval (CI) 2.6-26.0), repeated episodes of apnea (OR = 5.7, 95% CI 1.2-27.0), low birth weight (< 2,500 g) (OR = 3.4, 95% CI 1.1-11.0), a family history of sudden infant death (OR = 2.9, 95% CI 1.1-7.5), and maternal smoking during pregnancy (OR = 2.2, 95% CI 1.0-4.5) were associated with early SIDS. This study identified two distinct subgroups of SIDS infants characterized by different risk conditions and ages at death. These results underline a multiple-cause hypothesis for SIDS etiology which involves a genetic predisposition, immaturity in the first months of life, and environmental factors acting at various ages.     

Implementation of new technology for persons with mental retardation and the importance of staff education

OBJECTIVE: To examine the association between plasma vitamin A levels and outcome measures in very low birthweight (VLBW) infants, including meta-analysis of all observational studies. DESIGN: A prospective observational longitudinal study of plasma vitamin A levels measured in the cord blood; maternal blood in the first 48 h after delivery; and the infants' blood at 48 h, 7 days and 28 days of age and correlated with antenatal and postnatal events. A meta-analysis of all published observational studies on the association of vitamin A with respiratory outcome in the VLBW infant was undertaken. PATIENTS: Fifty-seven infants (88% of all eligible) VLBW infants (< 1500 g) admitted from January through October 1993 to one of two regional neonatal intensive care units in the South Island of New Zealand. RESULTS: Exposure to antenatal steroids led to a significant increase in infant cord plasma vitamin A levels (P = 0.003), but no influence on infant plasma vitamin A levels at any other time. Exposure to postnatal steroids produced a significant rise in infant plasma vitamin A levels between 7 and 28 days (P = 0.008). After controlling for gestational age, antenatal and postnatal steroid exposure, low vitamin A levels at 48 h increased the risk of developing chronic lung disease (odds ratio for 50 microg/l decrease: 2.04, 95% CI 1.19-5.77) and bronchopulmonary dysplasia (odds ratio 1.96, 95% CI 1.14-6.87). On combining our results in meta-analysis with those of other published prospective observational studies, infants with chronic lung disease had lower plasma vitamin A levels at all times. CONCLUSIONS: Our results support an association between low plasma vitamin A levels and adverse outcome in the VLBW infant.     

Development of a new introduction technique for the pulsatile catheter pump

Hypoplastic pineal glands and decreased melatonin levels are found in sudden infant death syndrome. Excess oxygen radical production and inadequate radical quenching is suggested to cause oxidative stress in the brain of sudden infant death syndrome victims. Loss of intraventricular cerebrospinal fluid melatonin could play an important role in the disease process. Infants at risk might be protected by exogenous melatonin.     

Effect of maternal cigarette smoking on pregnancy complications and sudden infant death syndrome

BACKGROUND: The purpose of this study was to estimate the annual morbidity and mortality among fetuses and infants that can be attributed to the use of tobacco products by pregnant women. METHODS: Published research reports identified by literature review were combined in a series of meta-analyses to compute pooled risk ratios, which, in turn, were used to determine the population attributable risk. RESULTS: Each year, use of tobacco products is responsible for an estimated 19,000 to 141,000 tobacco-induced abortions, 32,000 to 61,000 infants born with low birthweight, and 14,000 to 26,000 infants who require admission to neonatal intensive care units. Tobacco use is also annually responsible for an estimated 1900 to 4800 infant deaths resulting from perinatal disorders, and 1200 to 2200 deaths from sudden infant death syndrome (SIDS). CONCLUSIONS: Tobacco use is an important preventable cause of abortions, low birthweight, and deaths from perinatal disorders and SIDS. All pregnant women should be advised that smoking places their unborn children in danger. The low success rate of smoking cessation among pregnant women suggests that efforts to reduce the complications of pregnancy attributable to tobacco use by pregnant women should focus on preventing nicotine addiction among teenaged girls.     

12-hour pattern of the waking state in the normal infant and in the infant who has survived the 'syndrome of sudden infant death' (author's transl)

The authors report the results of 16 sleep EEGs carried out on 5 infants said to have survived the syndrome of sudden infant death (near-miss group) and 5 controls. The recordings were performed at 1.5 months, 3 months and 4.5 months, times when the risk of sudden death is maximum. The EEG appearance and the organization of sleep patterns have been studied in both groups. The various states of wakefulness, and the modalities of sleep and waking were subjected to statistical analysis with respect to age. The study showed no significant difference between the percentages of different states of wakefulness in the control and 'near-miss' group, but there were more sleep onsets in active sleep (REM) in this group compared with the controls and there were fewer waking periods, although when they occurred these were more prolonged.     

Hypoxanthine in vitreous humor and cerebrospinal fluid--a marker of postmortem interval and prolonged (vital) hypoxia? Remarks also on hypoxanthine in SIDS

Hypoxanthine (Hx) is a degradation product of adenosine. Increased concentrations were reported in cases of hypoxia as well as with prolonged postmortem interval (PMI). Hx is recommended as an indicator of prolonged (cerebral) hypoxia, for example in vitamins of sudden infant death as well as a new biochemical method for estimation of postmortem time. The correlation of vitreous Hx values with the time since death was reported to be even higher than the vitreous potassium (K+) values. The authors' investigations on 92 bodies with known time since death gave a completely opposite result: a much higher correlation between vitreous K+ and time since death than vitreous Hx. The possible discrepancies between these different results will be discussed (disturbing of intra-ocular fluid dynamics by repeated sample-taking in the study of Rognum et al. The results published so far on vitreous Hx values in sudden infant death syndrome (SIDS) cases as an indicator for a prolonged cerebral hypoxia are also not convincing. When vitreous concentrations of newborn infants or infants of age < 6 months are compared to those of older infants or adults the vitreous diameter must be taken into consideration (diffusion gradient; Fick's law of diffusion). The discrepant results on vitreous Hx as a measure of vital hypoxia and PMI will be discussed. The authors' results on Hx determinations on cerebrospinal fluid in comparison to cerebrospinal spinal (CSF) potassium will also be briefly addressed.     

Evidence for retarded kidney growth in sudden infant death syndrome

The aim of the study was to compare the growth rate of the kidneys of infants who died of sudden infant death syndrome (SIDS) and control babies under 1 year; 227 infants who died in St. Petersburg from 1983 to 1990 and who met the criteria for SIDS were included in the study; 138 infants who died suddenly of respiratory infections within the same period constituted a control group. The infants did not have signs of dehydration, malformations, tumours or intrauterine infections. Morphologically the kidneys were intact. Factors which might influence the weight of the kidneys at the time of death were: the cause of death (whether SIDS or not), gender, gestational age, weight, length and ponderal index at birth, age, weight and length at death. Stepwise (forward) linear regression analysis identified three variables which in combination most accurately and independently influenced the predicted weight of the kidneys. These were the cause of death, gender and weight at the time of death. The weight of the kidneys increased by 6.0 g for each increase in total body weight of 1,000 g [95% confidence interval (CI) 5.0-7.0 g], in boys the kidney weight was 3.3 g (95% CI 1.6-5.0 g) higher than in girls and in the SIDS babies kidney weight was 2.5 g (95% CI 0.8-4.2 g) less than controls. Delayed kidney growth may be an indicator of increased risk of SIDS in infants under 1 year and may contribute in some cases.     

Mother's insightfulness regarding their infants' internal experience: Relations with maternal sensitivity and infant attachment.

This study examined the associations among mothers' insightfulness into their infants' internal experience, mothers' sensitivity to their infants' signals, and infants' security of attachment to their mothers. The insightfulness of 129 mothers of 12-month-old infants was assessed by showing mothers 3 videotaped segments of observations of their infants and themselves and interviewing them regarding their infants' and their own thoughts and feelings. Interviews were classified into 1 insightful and 3 noninsightful categories. Mothers' sensitivity was assessed during play sessions at home and at the laboratory, and infant-mother attachment was assessed with the Strange Situation. Mothers classified as positively insightful were rated as more sensitive and were more likely to have securely attached children than were mothers not classified as positively insightful. Insightfulness also accounted for variance in attachment beyond the variance explained by maternal sensitivity. These findings add an important dimension to research on caregiving, suggesting that mothers' seeking of explanations for the motives underlying their infants' behavior is related to both maternal sensitivity and infant attachment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

SIDS cases have increased levels of interleukin-6 in cerebrospinal fluid

Cerebrospinal fluid (CSF) from 20 infants who died of sudden infant death syndrome (SIDS), 7 cases of infectious death and 5 cases of violent death were examined with respect to concentrations of interleukin-6 (IL-6). The measurements were performed by ELISA. IL-6 levels in SIDS were significantly lower than in infectious death (p < 0.02), but significantly higher than in violent death (p < 0.02). Since IL-6 plays an important role in immune responses and may induce fever, the findings may suggest that immune activation plays a role in SIDS. The presence of cytokines in the central nervous system (CNS) may cause respiratory depression, especially in vulnerable infants.