Unsafe sleep practices and an analysis of bedsharing among infants dying suddenly and unexpectedly: results of a four-year, population-based, death-scene investigation study of sudden infant death syndrome and related deaths

Qualitative analysis of beliefs and perceptions about sudden infant death syndrome in African-American mothers: implications for safe sleep recommendations

OBJECTIVE

To investigate, by using qualitative methods, perceptions about sudden infant death syndrome (SIDS) in African-American parents and how these influence decisions.

STUDY DESIGN

Eighty-three mothers participated in focus groups or individual interviews. Interviews probed reasons for decisions about infant sleep environment and influences affecting these decisions. Data were coded, and themes were developed and revised in an iterative manner as patterns became more apparent.

RESULTS

Themes included lack of plausibility, randomness, and vigilance. Many mothers believed that the link between SIDS and sleep position was implausible. Because the cause of SIDS was unknown, they did not understand how certain behaviors could be defined as risk factors. This confusion was reinforced by perceived inconsistency in the recommendations. Most mothers believed that SIDS occurred randomly ("God's will") and that the only way to prevent it was vigilance.

CONCLUSIONS

Many African-American mothers may not understand the connection between SIDS and sleep behaviors or believe that behavior (other than vigilance) cannot affect risk. These beliefs, if acted on, may affect rates of safe sleep practices. Efforts to explain a plausible link between SIDS and safe sleep recommendations and to improve consistency of the message may result in increased adherence to these recommendations.

A practical classification schema incorporating consideration of possible asphyxia in cases of sudden unexpected infant death

Although the rate of the sudden infant death syndrome (SIDS) has decreased over the last two decades, medical examiners and coroners are increasingly unwilling to use the SIDS diagnosis, particularly when there is an unsafe sleeping environment that might pose a risk for asphyxia. In order to reliably classify the infant deaths studied in a research setting in the mixed ancestory population in Cape Town, South Africa, we tested a classification system devised by us that incorporates the uncertainty of asphyxial risks at an infant death scene. We classified sudden infant deaths as: A) SIDS (where only a trivial potential for an overt asphyxial event existed); B) Unclassified-Possibly Asphyxial-Related (when any potential for an asphyxial death existed); C) Unclassified-Non-Asphyxial-Related (e.g., hyperthermia); D) Unclassified-No autopsy and/or death scene investigation; and E) Known Cause of Death. Ten infant deaths were classified according to the proposed schema as: SIDS, n = 2; Unclassified-Possibly Asphyxial-Related, n = 4; and Known Cause, n = 4. A conventional schema categorized the deaths as 6 cases, SIDS, and 4 cases, Known Cause, indicating that 4/6 (67%) of deaths previously classified as SIDS are considered related importantly to asphyxia and warrant their own subgroup. This new classification schema applies a simpler, more qualitative approach to asphyxial risk in infant deaths. It also allows us to test hypotheses about the role of asphyxia in sudden infant deaths, such as in brainstem defects in a range of asphyxial challenges.

Bed sharing among mother-infant pairs in Klang district, Peninsular Malaysia and its relationship to breast-feeding

OBJECTIVE

The aim of the study was to determine the prevalence of mother-infant bed sharing in Klang district, Peninsular Malaysia and to identify factors associated with bed sharing.

METHOD

This was a cross-sectional study involving 682 mother-infant pairs with infants up to 6 months attending government clinics in Klang district, Peninsular Malaysia. Data were collected by face-to-face interview using a pretested structured questionnaire for a 4-month period in 2006. Data regarding maternal, paternal, obstetric, infant, occupancy, breast-feeding characteristics, and bed-sharing practice were collected. Data on bed sharing were based on practice in the past 1-month period. Bed sharing was defined as an infant sharing a bed with mother, and infant must be within arms reach from the mother, whereas a bed was defined as either a sleeping mattress placed on a bed frame or placed on the floor. The prevalence of bed sharing was estimated. Relationship and magnitude of association between independent factors and bed sharing were examined using odds ratio and 95% confidence interval. Logistic regression analysis was used to control for confounding factors.

RESULTS

The prevalence of bed sharing among mothers with infants aged between 1 and 6 months was 73.5% (95% confidence interval: 70.0-76.7). In multivariate analysis, urban/rural differences, mothers' ethnicity, occupation, family income, husbands' support on bed sharing, number of children younger than 12 years staying in the house, and breast-feeding were associated with bed sharing.

CONCLUSIONS

These factors need to be considered in analyzing the overall risks and benefits of bed sharing, paying attention to breastfeeding practices.

Bed-sharing at 3 months and breast-feeding at 1 year in southern Brazil

OBJECTIVE

To investigate the association between bedsharing at age 3 months and breastfeeding (BF) at age 12 months.

STUDY DESIGN

Almost all children born in Pelotas, Brazil in 2004 (99.2%) were enrolled in a cohort study. At birth, age 3 months, and age 12 months, mothers were interviewed to gather information on sociodemographic, reproductive, BF, and bedsharing characteristics. Bedsharing was defined as habitual sharing of a bed between mother and child for the entire night or part of the night. The analysis was limited to children from single births who were breastfed at 3 months. Multivariate analyses were carried out using Poisson regression.

RESULTS

Of 4231 live births, 2889 were breastfed at age 3 months. The prevalence of BF at age 12 months was 59.2% in the children who bedshared at 3 months and 44% in those who did not (adjusted prevalence ratio [PR] for weaning= 0.75; 95% confidence interval [CI] = 0.69-0.81; P < .001). Among children who were exclusively breastfed at 3 months, 75.1% of those who also bedshared were still breastfed at age 12 months, versus 52.3% of those who did not bedshare (adjusted PR = 0.63; 95% CI = 0.53- 0.75; P < .001). The adjusted PR was 0.74 (95% CI = 0.60-0.90; P = .003) in children who were predominantly breastfed and 0.83 (95% CI = 0.76-0.90; P < .001) in those who were partially breastfed.

CONCLUSIONS

Bedsharing at 3 months protected against weaning up to age 12 months.

Airway covering during bed-sharing

BACKGROUND

Parent-infant bed-sharing is a common practice in Western post-industrial nations with up to 50% of infants sleeping with their parents at some point during early infancy. However, researchers have claimed that infants may be at risk of suffocation or sudden infant death syndrome related to airway covering or compression in the bed-sharing environment. To further understand the role of airway covering and compression in creating risks for bed-sharing infants, we report here on a sleep-lab trial of two infant sleep conditions.

METHODS

In a sleep-lab environment 20 infants aged 2-3 months old slept in their parents' bed, and in a cot by the bed, on adjacent nights. Infants' oxygen saturation and heart rate were monitored physiologically while infant and parental behaviours were recorded via ceiling-mounted infra-red cameras. Infants served as their own controls. Continuous 8-h recordings were obtained for covering of infant external airways, levels of infant oxygen saturation, infant heart rate, evidence of parental compression/overlying of infant, circumstances leading up to potential infant airway obstruction, and parental awareness of and responses to infant airway covering.

RESULTS

The majority of infants (14/20) spent some part of the bed night with their airways (both mouth and nose) covered, compared with 2/20 on the cot night; however, no consistent effect on either oxygen saturation levels or heart rate was revealed, even during prolonged bouts of airway covering. All cases of airway covering were initiated by parents; 70% were terminated by parents, the remainder by infants. Seven bouts of potential compression were observed with parental limbs resting across infant bodies for lengthy periods, however, in only two cases was the full weight of a parental limb resting on an infant, both events lasting less than 15 s, both being terminated by infant movement.

CONCLUSION

Although numerous authors have suggested that bed-sharing infants face risks because of airway covering by bed-clothes or parental bodies, the present trial does not lend support to this hypothesis.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Infant crying and sleeping: helping parents to prevent and manage problems

This article summarizes the current understanding of infant crying and sleeping problems, together with the implications of this understanding for services and research, with a focus on the first months of infancy.

Infant sleep location: associated maternal and infant characteristics with sudden infant death syndrome prevention recommendations

OBJECTIVE

To identify factors associated with infant sleep location.

STUDY DESIGN

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).

RESULTS

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).

CONCLUSIONS

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.

Mother-infant cosleeping, breastfeeding and sudden infant death syndrome: what biological anthropology has discovered about normal infant sleep and pediatric sleep medicine

Twenty years ago a new area of inquiry was launched when anthropologists proposed that an evolutionary perspective on infancy could contribute to our understanding of unexplained infant deaths. Here we review two decades of research examining parent-infant sleep practices and the variability of maternal and infant sleep physiology and behavior in social and solitary sleeping environments. The results challenge clinical wisdom regarding "normal" infant sleep, and over the past two decades the perspective of evolutionary pediatrics has challenged the supremacy of pediatric sleep medicine in defining what are appropriate sleep environments and behaviors for healthy human infants. In this review, we employ a biocultural approach that integrates diverse lines of evidence in order to illustrate the limitations of pediatric sleep medicine in adopting a view of infants that prioritizes recent western social values over the human infant's biological heritage. We review what is known regarding infant sleeping arrangements among nonhuman primates and briefly explore the possible paleoecological context within which early human sleep patterns and parent-infant sleeping arrangements might have evolved. The first challenges made by anthropologists to the pediatric and SIDS research communities are traced, and two decades of studies into the behavior and physiology of mothers and infants sleeping together are presented up to the present. Laboratory, hospital and home studies are used to assess the biological functions of shared mother-infant sleep, especially with regard to breastfeeding promotion and SIDS reduction. Finally, we encourage other anthropologists to participate in pediatric sleep research using the unique skills and insights anthropological data provide. By employing comparative, evolutionary and cross-cultural perspectives an anthropological approach stimulates new research insights that influence the traditional medical paradigm and help to make it more inclusive. That this review will potentially stimulate similar research by other anthropologists is one obvious goal. That this article might do so makes it ever more possible that anthropologically inspired work on infant sleep will ultimately lead to infant sleep scientists, pediatricians, and parents becoming more informed about the consequences of caring for human infants in ways that are not congruent with their evolutionary biology.

Physician recommendations regarding SIDS risk reduction: a national survey of pediatricians and family physicians

BACKGROUND

Sudden infant death syndrome (SIDS) is a leading cause of death among infants. Recently, new SIDS risk factors have emerged.

OBJECTIVE

To determine knowledge and recommendations of pediatricians and family physicians regarding SIDS-relevant practices.

METHODS

Cross-sectional survey of 3005 pediatricians and family physicians.

RESULTS

Of the 783 respondents, pediatricians comprised 64% and females 52%; 78% recognized supine as the recommended sleep position; 69% recommended supine. Almost all physicians recommended a firm mattress, 82% recommended a crib or bassinet, and 42% recommended a separate room for infants; 63% had no preference about or did not recommend restricting pacifier use. Pediatricians were more likely to discuss infant sleep position and room sharing at every well-child visit.

CONCLUSIONS

Knowledge about recommended infant sleep position is relatively high, but there are gaps in physician knowledge regarding safe sleep recommendations. Greater dissemination of information is required, and barriers to implementation need to be identified and addressed.

Deaths and injuries attributed to infant crib bumper pads

OBJECTIVE

To document deaths attributed to bumper pads and injuries from their use that are potentially preventable.

STUDY DESIGN

The US Consumer Product Safety Commission maintains files on cases voluntarily reported to them of deaths and injury related to commercial products. These cases represent an unknown fraction of total occurrences. We searched this database for deaths related to crib bumpers for the years 1985 to 2005. We also searched other Consumer Product Safety Commission databases for crib-related injuries that potentially might have been prevented by bumpers. Additionally, we examined 22 retail crib bumpers and described features that could be hazardous.

RESULTS

Twenty-seven accidental deaths reported by medical examiners or coroners were attributed to bumper pads. The mechanism of death included suffocation and strangulation by bumper ties. Twenty-five nonfatal injuries were identified, and most consisted of minor contusions. All retail bumpers had hazardous properties.

CONCLUSIONS

These findings suggest that crib and bassinet bumpers are dangerous. Their use prevents only minor injuries. Because bumpers can cause death, we conclude that they should not be used.

Risk factors, diagnosis and prevention of sudden unexpected infant death

The diagnosis of the cause of sudden unexpected infant death (SUID) is often difficult work for forensic pathologists. Its misdiagnosis or misclassification is the cause of crucial epidemiological and medicolegal problems. During the sudden infant death syndrome (SIDS) epidemic, many reports described the risk factors of SIDS as well as mechanical suffocation during sleep. Meadow's report has invited worldwide debate over whether the cause of SUID is attributable to SIDS or suffocation. On the basis of this background, the problems concerning causal diagnosis and risk factors, particularly the accidental suffocation of infants during sleep, and the specific pattern of suffocation, was reviewed from the forensic pathological viewpoint. The following tasks remain to be done for the future: (1) to avoid preventable SUIDs, the most effective measure worldwide is to identify high-risk factors for all SUIDs, including SIDS, accidental suffocation and undetermined causes, and then transmit this information to the public. (2) SIDS should be uniformly defined and diagnosed as strictly as possible to gain its reliability in the public health community and in a legal framework.

Pulmonary intra-alveolar hemorrhage in SIDS and suffocation

The differentiation of SIDS from accidental or inflicted suffocation may be impossible in some cases. Severe pulmonary intra-alveolar hemorrhage has been suggested as a potential marker for such differentiation. Our aims are to: (1) Compare pulmonary hemorrhage in SIDS and a control group comprised of infants whose deaths were attributed to accidental or inflicted suffocation. (2) Review individual cases with the most severe pulmonary hemorrhage regardless of the cause of death, and (3) Assess the effect of age, bedsharing, cardiopulmonary resuscitation, and postmortem interval, with regard to the severity of pulmonary hemorrhage in SIDS cases. We conducted a retrospective study of all postneonatal cases accessioned by the Office of the Medical Examiner in San Diego County, California who died of SIDS or suffocation between 1999 and 2004. A total of 444 cases of sudden infant death caused by SIDS (405), accidental suffocation (36), and inflicted suffocation (3) from the San Diego SIDS/SUDC Research Project database were compared using a semiquantitative measure of pulmonary intra-alveolar hemorrhage [absent (0) to severe (4)]. Grades 3 or 4 pulmonary hemorrhage occurred in 33% of deaths attributed to suffocation, but in only 11% of the SIDS cases, however, all grades of pulmonary hemorrhage occurred in both groups. Therefore, our results indicate that the severity of pulmonary hemorrhage cannot be used in isolation to determine the cause or manner of sudden infant death. Among SIDS cases, those with a higher pulmonary hemorrhage grade (3 or 4) were more likely to bedshare, and with more than one co-sleeper, than those with a lower pulmonary hemorrhage grade (0 or 1). We conclude that each case must be evaluated on its own merits after thorough review of the medical history, circumstances of death, and postmortem findings.

The Controversy About What Constitutes Safe and Nurturant Infant Sleep Environments

In 1999, the U.S. Consumer Product Safety Commission stated that cribs provide the safest sleep environment for infants. Scientific data fails to support that statement and controversy continues in the scientific, medical, and parenting communities. Recent data demonstrate that cribs may represent the most unsafe sleep. This article seeks to inform health care professionals of the issues involved in the controversy and to offer guidelines for educating parents about safe and unsafe sleep practices.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN/METHODS

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

RESULTS

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

CONCLUSIONS

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

Recent national trends in sudden, unexpected infant deaths: more evidence supporting a change in classification or reporting

The recent US decline in sudden infant death syndrome (SIDS) rates may be explained by a shift in how these deaths are classified or reported. To examine this hypothesis, the authors compared cause-specific mortality rates for SIDS, other sudden, unexpected infant deaths, and cause unknown/unspecified, and they evaluated trends in the age and month of death for these causes using 1989-2001 US linked birth/death certificate data. Reported deaths in state and national data were compared to assess underreporting or overreporting. SIDS rates declined significantly from 1989-1991 to 1995-1998, while deaths reported as cause unknown/unspecified and other sudden, unexpected infant deaths, such as accidental suffocation and strangulation in bed (ASSB), remained stable. From 1999-2001, the decline in SIDS rates was offset by increasing rates of cause unknown/unspecified and ASSB. Changes in the cause-specific age at death and month of death distributions suggest that cases once reported as SIDS are now being reported as ASSB and cause unknown/unspecified. Most of the decline in SIDS rates since 1999 is likely due to increased reporting of cause unknown/unspecified and ASSB. Standardizing data collection at death scenes and improving the reporting of cause of death on death certificates should improve national vital records data and enhance prevention efforts.

An 8 year study of risk factors for SIDS: bed-sharing versus non-bed-sharing

BACKGROUND

It is unclear if it is safe for babies to bed share with adults. In Ireland 49% of sudden infant death syndrome (SIDS) cases occur when the infant is bed-sharing with an adult.

OBJECTIVE

To evaluate the effect of bed-sharing during the last sleep period on risk factors for SIDS in Irish infants.

DESIGN

An 8 year (1994-2001) population based case control study of 287 SIDS cases and 831 controls matched for date, place of birth, and sleep period. Odds ratios and 95% confidence intervals were calculated by conditional logistic regression.

RESULTS

The risk associated with bed-sharing was three times greater for infants with low birth weight for gestation (UOR 16.28 v 4.90) and increased fourfold if the combined tog value of clothing and bedding was > or =10 (UOR 9.68 v 2.34). The unadjusted odds ratio for bed-sharing was 13.87 (95% CI 9.58 to 20.09) for infants whose mothers smoked and 2.09 (95% CI 0.98 to 4.39) for non-smokers. Age of death for bed-sharing and sofa-sharing infants (12.8 and 8.3 weeks, respectively) was less than for infants not sharing a sleep surface (21.0 weeks, p<0.001) and fewer bed-sharing cases were found prone (5% v 32%; p = 0.001).

CONCLUSION

Risk factors for SIDS vary according to the infant's sleeping environment. The increased risk associated with maternal smoking, high tog value of clothing and bedding, and low z scores of weight for gestation at birth is augmented further by bed-sharing. These factors should be taken into account when considering sleeping arrangements for young infants.

The relation between child death and child maltreatment

The death of a child is a sentinel event in a community, and a defining marker of a society's policies of safety and health. Child death as a result of abuse and neglect is a tragic outcome that occurs in all nations of the world. The true incidence of fatal child abuse and neglect is unknown. The most accurate incidence data of such deaths have been obtained from countries where multi-agency death review teams analyse the causes of child fatalities, as is done in the United States and Australia.

The changing concept of sudden infant death syndrome: diagnostic coding shifts, controversies regarding the sleeping environment, and new variables to consider in reducing risk

There has been a major decrease in the incidence of sudden infant death syndrome (SIDS) since the American Academy of Pediatrics (AAP) released its recommendation in 1992 that infants be placed down for sleep in a nonprone position. Although the SIDS rate continues to fall, some of the recent decrease of the last several years may be a result of coding shifts to other causes of unexpected infant deaths. Since the AAP published its last statement on SIDS in 2000, several issues have become relevant, including the significant risk of side sleeping position; the AAP no longer recognizes side sleeping as a reasonable alternative to fully supine sleeping. The AAP also stresses the need to avoid redundant soft bedding and soft objects in the infant's sleeping environment, the hazards of adults sleeping with an infant in the same bed, the SIDS risk reduction associated with having infants sleep in the same room as adults and with using pacifiers at the time of sleep, the importance of educating secondary caregivers and neonatology practitioners on the importance of "back to sleep," and strategies to reduce the incidence of positional plagiocephaly associated with supine positioning. This statement reviews the evidence associated with these and other SIDS-related issues and proposes new recommendations for further reducing SIDS risk.

Perinatal periods of risk: analysis of fetal-infant mortality rates in Kansas City, Missouri

OBJECTIVES

The Perinatal Periods of Risk (PPOR) technique was used to analyze resident fetal and infant death data from Kansas City, Missouri, for the period 1998-2002. Results offer important information that can be used to develop community-based prevention strategies related to racial/ethnic disparities in infant mortality rates (IMR).

METHODS

The PPOR approach for fetal and infant mortality can be mapped by birthweight at delivery and time of death into four strategic prevention areas: 1) Maternal Health/Prematurity (MHP), 2) Maternal Care (MC), 3) Newborn Care (NC), and 4) Infant Health (IH). For this analysis, all fetal and infant death certificates from the metropolitan Kansas City area were linked to their birth certificates and those associated with residents of Kansas City, Missouri, proper were used to create the dataset used in this analysis. Due to the small number of fetal and infant deaths among other ethnic groups, the analysis was restricted to a comparison of the disparity of IMR between Blacks, Whites, and a national non-Hispanic white reference group. The Kitagawa formula was used to determine contribution to excess deaths from birthweight-specific mortality and birthweight distribution rates. Logistic regression techniques were used to identify risk factors for death among Black fetuses and infants with very low birthweights and also deaths due to sudden infant death syndrome (SIDS).

RESULTS

The PPOR analysis showed that of the excess deaths among black infants, when compared to a national reference group, 47% was attributable to MHP and another 29% was attributable to IH. Differences in MC and NC only accounted for 27 and 8% of the total excess deaths. During the study period, rates of sudden infant death syndrome (SIDS) were found to be significantly higher among Blacks as compared to Whites (2.12 vs. 0.81 per 1,000). An analysis of maternal characteristics for SIDS deaths among blacks using a step-wise logistic regression model, found that maternal age less than 20 years old, previous births, inadequate prenatal care, and being a Medicaid recipient were significant-adjusted odds ratios of 23.7 (95% Cl 10.48, 53.67), 8.4 (95% Cl 3.64, 19.21), 2.9 (95% Cl 1.38, 6.05) and 2.5 (95% Cl 1.04, 5.84), respectively.

CONCLUSIONS

PPOR is an easy to use approach that helps focus community initiatives for improving maternal and infant health. In Kansas City, Missouri, efforts to further lower IMR in blacks can be achieved through the reduction of risk factors affecting maternal health and through maternal education to improve infant health.

Bedsharing and maternal smoking in a population-based survey of new mothers

OBJECTIVE

Sudden infant death syndrome (SIDS) remains the number 1 cause of postneonatal infant death. Prone infant sleep position and maternal smoking have been established as risk factors for SIDS mortality. Some studies have found that bedsharing is associated with SIDS, but, to date, there is only strong evidence for a risk among infants of smoking mothers and some evidence of a risk among young infants of nonsmoking mothers. Despite the lack of convincing scientific evidence, bedsharing with nonsmoking mothers remains controversial. In some states, nonsmoking mothers are currently being told that they should not bedshare with their infants, and mothers of infants who died of SIDS are told that they caused the death of their infant because they bedshared. The objective of this study was to explore the relationship between maternal smoking and bedsharing among Oregon mothers to explore whether smoking mothers, in contrast to nonsmoking mothers, are getting the message that they should not bedshare.

METHODS

Oregon Pregnancy Risk Assessment Monitoring System surveys a stratified random sample, drawn from birth certificates, of women after a live birth. Hispanic and non-Hispanic black, non-Hispanic Asian/Pacific Islander and non-Hispanic American Indian/Alaskan Native women, and non-Hispanic white women with low birth weight infants are oversampled to ensure sufficient numbers for stratified analysis. The sample then was weighted to reflect Oregon's population. In 1998-1999, 1867 women completed the survey (73.5% weighted response). The median time from birth to completion of the survey was 4 months. Women were asked whether they shared a bed with their infant "always," "almost always," "sometimes," or "never." Frequent bedsharing was defined as "always" or "almost always"; infrequent was defined as "sometimes" or "never."

RESULTS

Of all new mothers, 35.2% reported bedsharing frequently (always: 20.5%; almost always: 14.7%) and 64.8% infrequently (sometimes: 41.4%; never: 23.4%). Bedsharing among postpartum smoking mothers was 18.8% always, 12.6% almost always, 45.1% sometimes, and 23.6% never; this was not statistically different from among nonsmoking mothers. Results for prenatal smokers were similar. When stratified by race/ethnicity, there was no association between smoking and bedsharing in any racial or ethnic group. In univariable and multivariable logistic regression, there were no statistical differences in frequent or any bedsharing among either prenatal or postpartum smoking mothers compared with nonsmokers; the adjusted odds ratio for postpartum smokers who frequently bedshared was 0.73 (95% confidence interval [CI]: 0.42-1.25) and for any bedsharing was 1.05 (95% CI: 0.57-1.94). Results for prenatal smoking were similar. This is the first US population-based study to look at the prevalence of bedsharing among smoking and nonsmoking mothers. Bedsharing is common in Oregon, with 35.2% of mothers in Oregon reporting frequently bedsharing and an additional 41.4% sometimes bedsharing. There was no significant association between smoking and bedsharing for either prenatal or postpartum smokers among any racial or ethnic group. Smoking mothers were as likely to bedshare as nonsmoking mothers. The frequency of bedsharing in Oregon was similar to estimates from other sources. Our study has the advantage of being a population-based sample drawn from birth certificates, weighted for nonresponse.

CONCLUSIONS

Although a number of case series have raised concerns about the safety of mother-infant bedsharing, even among nonsmoking mothers, this has not yet been confirmed by careful, controlled studies. There have been 9 large-scale case-control studies of the relationship between bedsharing and SIDS. Three case-control studies did not stratify by maternal smoking status, but found no increased risk for SIDS. Six case control studies reported results stratified by maternal smoking status: 1 study, while asserting an association, provided an unexplained range of univariable odds ratios without CIs; 3 found no increased risk for older infants of nonsmoking mothers; and 2 found a risk only for infants <8-11 weeks of age. Despite the preponderance of evidence that bedsharing by nonsmoking mothers does not increase the risk for SIDS among older infants, the recent specter of bedsharing as a cause of SIDS, based on uncontrolled case series and medical examiners' anecdotal experience, has led some medical examiners to label a death "suffocation" or "overlay asphyxiation" simply because the infant was bedsharing at the time of death. This "diagnostic drift" may greatly complicate future studies of the relationship between bedsharing and SIDS. Epidemiologic evidence shows that there is little or no increased risk for SIDS among infants of nonsmoking mothers but increased risk among infants of smoking mothers and younger infants of nonsmoking mothers. It seems prudent to discourage bedsharing among all infants <3 months old. Young infants brought to bed to be breastfed should be returned to a crib when finished. It would be worthwhile for other researchers to reanalyze their previous data to evaluate the consistency of the interaction of young infant age and bedsharing. Large controlled studies that include infants who are identified as dying from SIDS, asphyxia, suffocation, and sudden unexplained infant death, analyzed separately and in combination, are needed to resolve this and other issues involving bedsharing, including the problem of diagnostic drift. Recommendations must be based on solid scientific evidence, which, to date, does not support the rejection of all bedsharing between nonsmoking mothers and their infants. Cribs should be available for those who want to use them. Nonsmoking mothers should not be pressured to abstain from bedsharing with their older infants; they should be provided with accurate, up-to-date scientific information. Infants also should not co-sleep with nonparents. In Oregon, if not elsewhere, the message that smoking mothers should not bedshare is not being disseminated effectively. Because it is not known whether the risk caused by smoking is associated with prenatal smoking, postpartum smoking, or both, bedsharing among either prenatal or postpartum smokers should be strongly discouraged. Much more public and private effort must be made to inform smoking mothers, in culturally competent ways, of the very significant risks of mixing bedsharing and smoking. Public health practitioners need to find new ways to inform mothers and providers that smoking mothers should not bedshare and that putting an infant of a nonsmoking mother to sleep in an adult bed should be delayed until 3 months of age.

Bedsharing, roomsharing, and sudden infant death syndrome in Scotland: a case-control study

OBJECTIVE

To examine the hypothesis that bedsharing with an infant is associated with an increased risk of sudden infant death syndrome (SIDS).

STUDY DESIGN

A 1:2, case:control study in Scotland UK, population 5.1 million, including 123 infants who died of SIDS between January 1, 1996 and May 31, 2000, and 263 controls. The main outcome measure was sharing a sleep surface during last sleep.

RESULTS

Sharing a sleep surface was associated with SIDS (multivariate OR 2.89, 95% CI 1.40, 5.97). The largest risk was associated with couch sharing (OR 66.9, 95% CI 2.8, 1597). Of 46 SIDS infants who bedshared during their last sleep, 40 (87%) were found in the parents' bed. Sharing a bed when <11 weeks (OR 10.20, 95% CI 2.99, 34.8) was associated with a greater risk, P = .010, compared with sharing when older (OR 1.07, 95% CI 0.32, 3.56). The association remained if mother did not smoke (OR 8.01, 95% CI 1.20, 53.3) or the infant was breastfed (OR 13.10, 95% CI 1.29, 133).

CONCLUSIONS

Bedsharing is associated with an increased risk of SIDS for infants <11 weeks of age. Sharing a couch for sleep should be strongly discouraged at any age.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Why babies should never sleep alone: a review of the co-sleeping controversy in relation to SIDS, bedsharing and breast feeding

There has been much controversy over whether infants should co-sleep or bedshare with an adult caregiver and over whether such practises increase the risk of SIDS or fatal accident. However, despite opposition from medical authorities or the police, many western parents are increasingly adopting night-time infant caregiving patterns that include some co-sleeping, especially by those mothers who choose to breast feed. This review will show that the relationships between infant sleep patterns, infant sleeping arrangements and development both in the short and long term, whether having positive or negative outcomes, is anything but simple and the traditional habit of labelling one sleeping arrangement as being superior to another without an awareness of family, social and ethnic context is not only wrong but possibly harmful. We will show that there are many good reasons to insist that the definitions of different types of co-sleeping and bedsharing be recognised and distinguished. We will examine the conceptual issues related to the biological functions of mother-infant co-sleeping, bedsharing and what relationship each has to SIDS. At very least, we hope that the studies and data described in this paper, which show that co-sleeping at least in the form of roomsharing especially with an actively breast feeding mother saves lives, is a powerful reason why the simplistic, scientifically inaccurate and misleading statement 'never sleep with your baby' needs to be rescinded, wherever and whenever it is published.

Sudden unexpected death in childhood: a report of 50 cases

Sudden unexplained death in childhood (SUDC) is rare, with a reported incidence in the United States of 1.5 deaths per 100,000 live births compared with 56 deaths per 100,000 live births for sudden infant death syndrome in 2001. The objectives of this study include a proposal for a general definition for SUDC and presentation of 36 cases of SUDC and 14 cases of sudden unexpected death in childhood. Cases were accrued through referrals or unsolicited via our Web page (http://www.sudc.org ). Our analyses tentatively suggest a SUDC profile characterized by cases being 1 to 3 years in age, predominantly male, and frequently having a personal and family history of seizures that are often associated with a fever. A history of recent minor head trauma is not uncommon. They are usually born at term as singletons and occasionally have a family history of sudden infant death syndrome or SUDC. Most are found prone, often with their face straight down into the sleep surface. Minor findings are commonly seen at postmortem examination but do not explain their deaths. Comprehensive review of the medical history and circumstances of death and performance of a complete postmortem examination including ancillary studies and extensive histologic sampling of the brain are critical in determining the cause of death in these cases of sudden unexpected childhood death. Legislation enabling research and formation of a multicenter research team is recommended to unravel the mystery of SUDC.

A comparison of the sleep-wake patterns of cosleeping and solitary-sleeping infants

This study examined whether 3-15, month-old cosleeping infants displayed differences in time spent in active versus quiet sleep, and in the number/duration of nighttime awakenings when compared with solitary-sleeping infants; and also whether they spent the majority of the night sleeping face-to-face, as previously reported. Nine cosleeping and nine solitary-sleeping infants were matched on age, gender, ethnicity, maternal age, and family SES. Video recordings of nighttime sleep yielded percentage of time in active sleep, quiet sleep, and awake, number of wakenings, and the percentage of time cosleeping infants and mothers spent face-to-face. Across age, cosleeping infants had more awakenings per night mean 5.8(1.50) versus 3.2(1.95); t = 3.16, p = .006). The percent of the nighttime spent awake did not differ between groups, suggesting that cosleeping infants had shorter awakenings. Cosleeping infants spent 40% of the night face-to-face with their mothers.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Developmental plasticity in respiratory control

Development of the mammalian respiratory control system begins early in gestation and does not achieve mature form until weeks or months after birth. A relatively long gestation and period of postnatal maturation allows for prolonged pre- and postnatal interactions with the environment, including experiences such as episodic or chronic hypoxia, hyperoxia, and drug or toxin exposures. Developmental plasticity occurs when such experiences, during critical periods of maturation, result in long-term alterations in the structure or function of the respiratory control neural network. A critical period is a time window during development devoted to structural and/or functional shaping of the neural systems subserving respiratory control. Experience during the critical period can disrupt and alter developmental trajectory, whereas the same experience before or after has little or no effect. One of the clearest examples to date is blunting of the adult ventilatory response to acute hypoxia challenge by early postnatal hyperoxia exposure in the newborn. Developmental plasticity in neural respiratory control development can occur at multiple sites during formation of brain stem neuronal networks and chemoafferent pathways, at multiple times during development, by multiple mechanisms. Past concepts of respiratory control system maturation as rigidly predetermined by a genetic blueprint have now yielded to a different view in which extremely complex interactions between genes, transcriptional factors, growth factors, and other gene products shape the respiratory control system, and experience plays a key role in guiding normal respiratory control development. Early-life experiences may also lead to maladaptive changes in respiratory control. Pathological conditions as well as normal phenotypic diversity in mature respiratory control may have their roots, at least in part, in developmental plasticity.

Effects of hyperthermia and muramyl dipeptide on IL-1beta, IL-6, and mortality in a neonatal rat model

The mechanism of sudden infant death syndrome (SIDS) may be linked to an interaction between the SIDS risk factors of hyperthermia and infection, and between their effect on cytokine production and arousal. This study investigated the effects of hyperthermia and a surrogate of infection (muramyl dipeptide or MDP) on cytokine production and mortality in a neonatal rat model. Four temperature groups were studied: 34 degrees C (baseline), 38 degrees C, 39 degrees C, and 40 degrees C. Body temperatures of neonatal rat pups in the hyperthermic groups were raised and maintained at the desired temperature (38 degrees C, 39 degrees C, or 40 degrees C) for 1 h and then returned to the baseline temperature (34 degrees C) for a further hour. The heat source was a covered, heatable aluminum metal plate in a Perspex heating chamber. Intraperitoneal (IP) injection of 0.1 mL normal saline was given 30 min before the start to control for MDP (protocol A). Four equivalent treatment groups were pretreated with MDP (25 nmol/animal) instead of normal saline (protocol B). IP ketamine (55 mg/kg) was used for anesthesia during the experiments and for euthanasia. Blood was collected by direct cardiac puncture immediately after the 2-h experiments and assayed for the cytokines IL-6 and IL-1beta by ELISA. Hyperthermia significantly increased the production of IL-6 (p = 0.049) but not IL-1beta and significantly increased mortality. Administration of MDP significantly increased the IL-1beta production (p = 0.006) but not IL-6. Cox regression analysis showed that MDP in combination with hyperthermia had a significant effect on mortality in the neonatal rat. The risk of experiencing mortality was two and half times higher in the MDP group than in the non-MDP group (p = 0.016) [hazard ratio (95% confidence interval) = 2.66 (1.20-5.92)]. We conclude that hyperthermia and a surrogate of infection (MDP) influence cytokine production and that the combination of heat stress and MDP increases mortality in the neonatal rat.

Triadic bed-sharing and infant temperature

The effects on infants of sleeping with their parents is currently the subject of much debate. One concern regarding infants who sleep in their parents' bed involves the possibility of overheating. Previous research reported a significantly greater core temperature of 0.1 degrees C among a cohort of bed-sharing infants compared with a matched cohort of infants sleeping alone. This paper presents a preliminary analysis of the overnight rectal temperature of 12 of the 20 infants who were monitored sleeping alone and with their parents on separate nights at the University of Durham Parent-Infant Sleep Lab. No significant differences were found in all night rectal temperature, or temperature from 2 h after sleep onset between bed-sharing and cot sleeping nights. These preliminary analyses suggest a night-time difference in rectal temperature between routine bed-sharers and routine cot sleepers, however, these findings will be further explored in the full analyses for this study.

Epidemiological investigation of sudden infant death syndrome infants--recommendations for future studies

In recent years the study of infant care practices within the sleeping environment has proved to be the single most important set of observations for reducing the risk of Sudden Infant Death Syndrome (SIDS). To further reduce the number of deaths and resolve the debate on safe infant care practice, a closer scrutiny of this environment is required. However, anecdotal observation from uncontrolled death-scene investigations and a reluctance to diagnose SIDS because of adverse social conditions or circumstantial evidence at the time of death is undermining future research. To investigate SIDS now means investigating the wider umbrella of all Sudden Unexpected Deaths in Infancy (SUDI) because of the potential for misdiagnosis. In trying to find out why SIDS infants die we have increasingly been forced to search for why infants survive in the first few months of life and it is this comparative component of epidemiological observation that has saved so many lives. A death-scene investigation is vital to any planned future investigation of SIDS but equally essential is a sleep-scene investigation of surviving infants to put any findings into context. SIDS infants are no longer scattered across the social strata and the cot is not the only environment in which they are found, social deprivation and use of the parental bed are now more discernable. Future studies should therefore reflect these changes with a second control group of surviving infants more closely matched to the type of environment in which SIDS infants might be found.

Population trends in sudden infant death syndrome

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

Prevalence, predictors, and attitudes toward cosleeping in an urban pediatric center

Cosleeping is the normative practice in many of the world's societies but is not endorsed by the Consumer Products Safety Commission or by the American Academy of Pediatrics. A survey was performed on 101 caregivers in an urban setting, designed to assess the prevalence of cosleeping and parental attitudes for this practice. Cosleeping rate was 88% with predictors being as follows: single parent (p=0.006), high school or less education (p=0.035), 2 or fewer rooms used for sleeping (p=0.023). A majority (65%) stated that cosleeping was acceptable.

The sleep of co-sleeping infants when they are not co-sleeping: evidence that co-sleeping is stressful

Co-sleeping proponents consider the practice to be "natural" and a potential protection against sudden infant death syndrome (SIDS); others consider the practice of an infant sleeping in the parents' bed for prolonged periods at night to place an infant at risk for harm or death. For this study, co-sleeping was investigated from a different perspective, that is, as a significant early experience to investigate as it may have implications for the infant's development. The sleep of 101 normal, full-term infants was recorded nonintrusively in the home for 24 hr periods when they were 5 weeks and 6 months old. Infants were assigned to three groups: short-term co-sleepers, long-term co-sleepers, and non-co-sleepers. Their sleep states and wakefulness were compared at the two ages and over age. At 5 weeks and 6 months, the long-term co-sleeping infants differed significantly from the non-co-sleepers on a number of measures: At 5 weeks, they showed more quiet sleep and longer bouts of quiet sleep; and at 6 months, they also showed less active sleep, fewer arousals in active sleep, and less wakefulness. Each of these differences indicates a markedly lower arousal level in the long-term co-sleeping infants. This sleep pattern has been repeatedly found to be an indicator of stress. We infer that a major source of stress for these infants is the experience of sleep disturbance documented for infants when they were co-sleeping. Based on extensive evidence for long-term effects of early stress, we conclude that co-sleeping should have significant implications for infants' neurobehavioral development.