Fern R. Hauck

Sudden infant death syndrome

Sudden infant death syndrome (SIDS) continues to be the most common cause of postneonatal infant death. SIDS is a complex, multifactorial disorder, the cause of which is still not fully understood. However, much is known now about environmental risk factors, some of which are modifiable. These include maternal and antenatal risk factors such as smoking during pregnancy, as well as infant-related risk factors such as non-supine sleeping position and soft bedding. Emerging evidence also substantiates an expanding number of genetic risk factors. Interactions between environmental and genetic risk factors may be of critical importance in determining an infants actual risk of SIDS. Although no practical way exists to identify which infants will die of SIDS, nor is there a safe and proven prevention strategy even if identification were feasible, reducing exposure to modifiable risk factors has helped to lower the incidence of SIDS. Current challenges include wider dissemination of guidelines to all people who care for infants, dissemination of guidelines in culturally appropriate ways, and surveillance of SIDS trends and other outcomes associated with implementation of these guidelines.

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 infants 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.

Breastfeeding and Reduced Risk of Sudden Infant Death Syndrome: A Meta-analysis

CONTEXT: Benefits of breastfeeding include lower risk of postneonatal mortality. However, it is unclear whether breastfeeding specifically lowers sudden infant death syndrome (SIDS) risk, because study results have been conflicting. OBJECTIVE: To perform a meta-analysis to measure the association between breastfeeding and SIDS. METHODS: We identified 288 studies with data on breastfeeding and SIDS through a Medline search (1966–2009), review articles, and meta-analyses. Twenty-four original case-control studies were identified that provided data on the relationship between breastfeeding and SIDS risk. Two teams of 2 reviewers evaluated study quality according to preset criteria; 6 studies were excluded, which resulted in 18 studies for analysis. Univariable and multivariable odds ratios were extracted. A summary odds ratio (SOR) was calculated for the odds ratios by using the fixed-effect and random-effect inverse-variance methods of meta-analysis. The Breslow-Day test for heterogeneity was performed. RESULTS: For infants who received any amount of breast milk for any duration, the univariable SOR was 0.40 (95% confidence interval [CI]: 0.35–0.44), and the multivariable SOR was 0.55 (95% CI: 0.44–0.69). For any breastfeeding at 2 months of age or older, the univariable SOR was 0.38 (95% CI: 0.27–0.54). The univariable SOR for exclusive breastfeeding of any duration was 0.27 (95% CI: 0.24–0.31). CONCLUSIONS: Breastfeeding is protective against SIDS, and this effect is stronger when breastfeeding is exclusive. The recommendation to breastfeed infants should be included with other SIDS risk-reduction messages to both reduce the risk of SIDS and promote breastfeeding for its many other infant and maternal health benefits.

Do Pacifiers Reduce the Risk of Sudden Infant Death Syndrome? A Meta-analysis

Objective. Pacifier use has been reported to be associated with a reduced risk of sudden infant death syndrome (SIDS), but most countries around the world, including the United States, have been reluctant to recommend the use of pacifiers because of concerns about possible adverse effects. This meta-analysis was undertaken to quantify and evaluate the protective effect of pacifiers against SIDS and to make a recommendation on the use of pacifiers to prevent SIDS. Methods. We searched the Medline database (January 1966 to May 2004) to collect data on pacifier use and its association with SIDS, morbidity, or other adverse effects. The search strategy included published articles in English with the Medical Subject Headings terms “sudden infant death syndrome” and “pacifier” and the keywords “dummy” and “soother.” Combining searches resulted in 384 abstracts, which were all read and evaluated for inclusion. For the meta-analysis, articles with data on the relationship between pacifier use and SIDS risk were limited to published original case-control studies, because no prospective observational reports were found; 9 articles met these criteria. Two independent reviewers evaluated each study on the basis of the 6 criteria developed by the American Academy of Pediatrics Task Force on Infant Positioning and SIDS; in cases of disagreement, a third reviewer evaluated the study, and a consensus opinion was reached. We developed a script to calculate the summary odds ratio (SOR) by using the reported ORs and respective confidence intervals (CI) to weight the ORs. We then pooled them together to compute the SOR. We performed the Breslow-Day test for homogeneity of ORs, Cochran-Mantel-Haenszel test for the null hypothesis of no effect (OR = 1), and the Mantel-Haenszel common OR estimate. The consistency of findings was evaluated and the overall potential benefits of pacifier use were weighed against the potential risks. Our recommendation is based on the taxonomy of the 5-point (A–E) scale adopted by the US Preventive Services Task Force. Results. Seven studies were included in the meta-analysis. The SOR calculated for usual pacifier use (with univariate ORs) is 0.90 (95% confidence interval [CI]: 0.79–1.03) and 0.71 (95% CI: 0.59–0.85) with multivariate ORs. For pacifier use during last sleep, the SORs calculated using univariate and multivariate ORs are 0.47 (95% CI: 0.40–0.55) and 0.39 (95% CI: 0.31–0.50), respectively. Conclusions. Published case-control studies demonstrate a significant reduced risk of SIDS with pacifier use, particularly when placed for sleep. Encouraging pacifier use is likely to be beneficial on a population-wide basis: 1 SIDS death could be prevented for every 2733 (95% CI: 2416–3334) infants who use a pacifier when placed for sleep (number needed to treat), based on the US SIDS rate and the last-sleep multivariate SOR resulting from this analysis. Therefore, we recommend that pacifiers be offered to infants as a potential method to reduce the risk of SIDS. The pacifier should be offered to the infant when being placed for all sleep episodes, including daytime naps and nighttime sleeps. This is a US Preventive Services Task Force level B strength of recommendation based on the consistency of findings and the likelihood that the beneficial effects will outweigh any potential negative effects. In consideration of potential adverse effects, we recommend pacifier use for infants up to 1 year of age, which includes the peak ages for SIDS risk and the period in which the infants need for sucking is highest. For breastfed infants, pacifiers should be introduced after breastfeeding has been well established.

International trends in sudden infant death syndrome: stabilization of rates requires further action

Sudden infant death syndrome (SIDS) is the leading cause of death among infants between 1 month and 1 year of age in the developed world. In the United States, SIDS accounts for 22% of all postneonatal deaths.1 Many countries have launched educational campaigns in an effort to prevent SIDS, focusing on the modifiable factors that had been shown previously to be associated with SIDS.2 Although campaigns vary in the content of their other messages, the leading message of every campaign has been avoidance of the prone position for sleeping infants. Dramatic declines in SIDS have been attributed to these campaigns, which were found to be primarily a result of decreases in prone-sleeping rates.3–9 Other recommendations, such as those advising mothers not to smoke during pregnancy, were followed less widely.3,7 The majority of campaigns were initiated in the late 1980s to early 1990s. In the United States, the American Academy of Pediatrics recommended the nonprone sleeping position for infants in 1992.10 The national Back to Sleep campaign began 2 years later and emphasized the same recommendation.11 In 2000, on the basis of new epidemiologic evidence, the American Academy of Pediatrics recommended back sleeping as the preferred position.7 In the United States, prone-sleeping rates have declined 81%, from 70% in 1992 to 13% in 2005, and supine-sleeping rates have increased from 13% to 72% over that period.12 The US rate of SIDS has declined 55% (from 1.20 in 1000 live births in 199213 to 0.54 in 1000 live births in 2005).14 Previously, SIDS rates were found to differ by country, as had reductions in rates.15 The purpose of this report is to compare more-recent international data on SIDS and postneonatal infant mortality rates to examine trends, discuss … Address correspondence to Fern R. Hauck, MD, MS, University of Virginia School of Medicine, Department of Family Medicine, PO Box 800729, Charlottesville, VA 22908-0729. E-mail: frh8e{at}virginia.edu

Swaddling and the Risk of Sudden Infant Death Syndrome: A Meta-analysis

CONTEXT: Swaddling is a traditional practice of wrapping infants to promote calming and sleep. Although the benefits and risks of swaddling in general have been studied, the practice in relation to sudden infant death syndrome remains unclear. OBJECTIVE: The goal of this study was to conduct an individual-level meta-analysis of sudden infant death syndrome risk for infants swaddled for sleep. DATA SOURCES: Additional data on sleeping position and age were provided by authors of included studies. STUDY SELECTION: Observational studies that measured swaddling for the last or reference sleep were included. DATA EXTRACTION: Of 283 articles screened, 4 studies met the inclusion criteria. RESULTS: There was significant heterogeneity among studies (I2 = 65.5%; P = .03), and a random effects model was therefore used for analysis. The overall age-adjusted pooled odds ratio (OR) for swaddling in all 4 studies was 1.58 (95% confidence interval [CI], 0.97–2.58). Removing the most recent study conducted in the United Kingdom reduced the heterogeneity (I2 = 28.2%; P = .25) and provided a pooled OR (using a fixed effects model) of 1.38 (95% CI, 1.05–1.80). Swaddling risk varied according to position placed for sleep; the risk was highest for prone sleeping (OR, 12.99 [95% CI, 4.14–40.77]), followed by side sleeping (OR, 3.16 [95% CI, 2.08–4.81]) and supine sleeping (OR, 1.93 [95% CI, 1.27–2.93]). Limited evidence suggested swaddling risk increased with infant age and was associated with a twofold risk for infants aged >6 months. LIMITATIONS: Heterogeneity among the few studies available, imprecise definitions of swaddling, and difficulties controlling for further known risks make interpretation difficult. CONCLUSIONS: Current advice to avoid front or side positions for sleep especially applies to infants who are swaddled. Consideration should be given to an age after which swaddling should be discouraged.

Infant Sleeping Arrangements and Practices During the First Year of Life

OBJECTIVES. Our goal was to examine the sleeping arrangements for infants from birth to 1 year of age and to assess the association between such arrangements and maternal characteristics. METHODS. Responses to the 3-, 6-, 9-, and 12-month questionnaires from the Infant Feeding Practices Study II were analyzed to assess sleep arrangements, including bed sharing, the latter defined as mother ever (in a given time frame) slept with the infant on the same sleeping surface for nighttime sleep. Women were also asked about the reasons for bed sharing or not bed sharing. RESULTS. Approximately 2300 women responded at 3 months, and 1800 at 12 months. At 3 months, 85% of the infants slept in the same room as their mother, and at 12 months that rate was 29%. At 3 months, 26% of the mothers did not use the recommended supine position for their infants nighttime sleep. The rate of noncompliance increased to 29% by 6 months and 36% by 12 months. The bed-sharing rates were 42% at 2 weeks, 34% at 3 months, and 27% at 12 months. Approximately two thirds of those who bed shared with their infant also shared the bed with their husband or partner, and 5% to 15% shared it with other children. The major reasons for bed sharing were to calm a fussy infant, facilitate breastfeeding, and help the infant and/or mother sleep better. The major reasons for not lying down with the infant were safety concerns. Non-Hispanic black mothers were more likely than non-Hispanic white mothers to use nonsupine infant sleep positions and to bed share. CONCLUSIONS. More than one third of the women in this cohort were noncompliant with safe-sleeping guidelines when their infant was 3 months old. Health care providers need to advise parents of current recommendations and discuss the risks and benefits of their choices for infant sleeping practices.

Racial and Ethnic Disparities in Infant Mortality

Racial and ethnic disparities in infant mortality in the United States seem to defy all attempts at elimination. Despite national priorities to eliminate these disparities, black infants are 2.5 times more likely to die in infancy compared with non-Hispanic white infants. This disparity is largely related to the greater incidence among black infants of prematurity and low birth weight, congenital malformations, sudden infant death syndrome, and unintentional injuries. This greater incidence, in turn, is related to a complex interaction of behavioral, social, political, genetic, medical, and health care access factors. Thus, to influence the persistent racial disparity in infant mortality, a highly integrated approach is needed, with interventions adapted along a continuum from childhood through the periods of young adulthood, pregnancy, postpartum and beyond. The content and methodologies of these interventions need to be adapted to the underlying behaviors, social influences, and technology and access issues they are meant to address.

Disparities in Perinatal Medicine: Preterm Birth, Stillbirth, and Infant Mortality

Infant mortality, stillbirths, and preterm births are major public health priorities with significant disparities based on race and ethnicity. Interestingly, when evaluating the rates over the past 30 to 50 years, the disparity persists in all three and is remarkably consistent. In the United States, the infant mortality rate is 6.7 deaths per 1,000 live births, the stillbirth rate is 6.2 per 1,000 deliveries, and the preterm birth rate is 12.8% of live births. The rates among non-Hispanic African Americans are dramatically higher, nearly double the infant mortality at 13.4 infant deaths per 1,000 live births, nearly double the stillbirth rate at 11.1 stillbirths per 1,000 deliveries, and one third higher with preterm births at 18.4% of live births. Despite numerous conferences, workshops, articles, and investigators focusing on this line of work, the disparities persist and, in some cases, are growing. In this article, we summarize a Eunice Kennedy Shriver National Institute of Child Health and Human Development workshop that focused on these disparities to identify the associated factors to determine their relative contributions, identify gaps in knowledge, and develop specific strategies to address the disparities in the short-term and long-term.

Inaccuracy of self-reported weights and heights among American Indian adolescents☆☆☆

To determine the accuracy of self-reported weights and heights and of relative weight status in a sample of American Indian adolescents, a survey was conducted in middle and high schools on or near three Indian reservations-Navajo, Choctaw, and Blackfeet. Self-reported weights and heights were compared with measured weights and heights. Participants were 12 through 19 years old. (N = 806, 47.4% male). Overall, both boys and girls underreported weight (mean difference = self-reported - measured mean values)(-3.4 +/- 13.1 and -4.6 +/- 13.0 lb, respectively) and overreported height (0.6 +/- 2.1 and 0.2 +/- 2.6 in, respectively) However, underweight boys and girls overreported weight (normal: -1.6 +/- 7.9 and -1.4 +/- 6.3; overweight: -7.5 +/- 17.9 and -11.6 +/- 19.0 lb, respectively). Although correlations between measured and reported weight, height, and body mass index (BMI) were high, the sensitivity of relative weight categories based on BMI using self-reported weight and height compared with measured weight and height was poor: 66.7% for underweight (BMI < 15th percentile, based on a national reference population), 88.9% for normal weight, and 73.6% for overweight (> 85th percentile). These results call into question the accuracy of self-reported weight and height measurements among American Indian youth and are similar to findings among non-American Indian adolescents. Therefore, their use in prevalence studies should be avoided, and they should be used cautiously in other types of epidemiologic studies.