Pacifier use and sudden infant death syndrome: results from the CESDI/SUDI case control study. CESDI SUDI Research Team

Pre- and postnatal safe sleep knowledge and planned as compared to actual infant sleep practices

BACKGROUND

Our objectives were to compare safe sleep knowledge, attitudes and planned vs. actual infant sleep practices among expectant mothers before and after their infant's birth and to determine whether differences (if present) were associated with any demographic variables.

METHODS

Study participants were surveyed at their 28-week prenatal and 6-week postpartum obstetric clinic visits from November 2019-February 2021. Due to COVID-19 pandemic cancellation of in-person postpartum visits, many participants received text messaging encouraging them to take the follow-up survey online. Frequency and comparative analyses were performed.

RESULTS

355 women (44%) completed both pre- and postnatal surveys. Many participants increased their safe sleep knowledge during the study. For example, of those who were unsure or thought it safe for a baby to sleep in a baby swing/bouncy seat, two-thirds (67/102, 66%) stated it was unsafe on the postnatal survey. In addition, many who were unsure or planned sleep practices considered unsafe prenatally reported utilizing safe sleep practices on their postnatal survey. For example, of those unsure or planning to use a crib bumper (17% of the total), almost all (88%) were not using one postnatally. Conversely, some participants who reported they would be following safe sleep practices prenatally were not doing so postpartum. For example, 13% of those stating they would place their child on their back reported using another sleep position on the postnatal survey. Certain demographics had higher proportions reporting this reversal for specific safe sleep practices. For example, non-Hispanic Whites (19%) as compared to other races/ethnicities (5%) and those with incomes ≥ $75,000 (21%) as compared with those with less income (9%) had higher proportions stating their infant would sleep in the same room but then reported postnatally they were sleeping in a different room, p = 0.0094 and p = 0.0138, respectively.

CONCLUSIONS

We observed increases in safe sleep knowledge and that some participants followed safer sleep practices than they had planned. However, there were also participants who planned to use safe sleep practices prenatally who were not doing so after their baby's birth. Our study identified demographics for which targeted safe sleep education and more effective interventions may be needed.

Evidence Base for 2022 Updated Recommendations for a Safe Infant Sleeping Environment to Reduce the Risk of Sleep-Related Infant Deaths

Every year in the United States, approximately 3500 infants die of sleep-related infant deaths, including sudden infant death syndrome (SIDS) (International Statistical Classification of Diseases and Related Health Problems 10th Revision [ICD-10] R95), ill-defined deaths (ICD-10 R99), and accidental suffocation and strangulation in bed (ICD-10 W75). After a substantial decline in sleep-related deaths in the 1990s, the overall death rate attributable to sleep-related infant deaths have remained stagnant since 2000, and disparities persist. The triple risk model proposes that SIDS occurs when an infant with intrinsic vulnerability (often manifested by impaired arousal, cardiorespiratory, and/or autonomic responses) undergoes an exogenous trigger event (eg, exposure to an unsafe sleeping environment) during a critical developmental period. The American Academy of Pediatrics recommends a safe sleep environment to reduce the risk of all sleep-related deaths. This includes supine positioning; use of a firm, noninclined sleep surface; room sharing without bed sharing; and avoidance of soft bedding and overheating. Additional recommendations for SIDS risk reduction include human milk feeding; avoidance of exposure to nicotine, alcohol, marijuana, opioids, and illicit drugs; routine immunization; and use of a pacifier. New recommendations are presented regarding noninclined sleep surfaces, short-term emergency sleep locations, use of cardboard boxes as a sleep location, bed sharing, substance use, home cardiorespiratory monitors, and tummy time. In addition, additional information to assist parents, physicians, and nonphysician clinicians in assessing the risk of specific bed-sharing situations is included. The recommendations and strength of evidence for each recommendation are published in the accompanying policy statement, which is included in this issue.

Sleep-Related Infant Deaths: Updated 2022 Recommendations for Reducing Infant Deaths in the Sleep Environment

Each year in the United States, ∼3500 infants die of sleep-related infant deaths, including sudden infant death syndrome (SIDS) (International Classification of Diseases, 10th Revision [ICD-10] R95), ill-defined deaths (ICD-10 R99), and accidental suffocation and strangulation in bed (ICD-10 W75). After a substantial decline in sleep-related deaths in the 1990s, the overall death rate attributable to sleep-related infant deaths has remained stagnant since 2000, and disparities persist. The triple risk model proposes that SIDS occurs when an infant with intrinsic vulnerability (often manifested by impaired arousal, cardiorespiratory, and/or autonomic responses) undergoes an exogenous trigger event (eg, exposure to an unsafe sleeping environment) during a critical developmental period. The American Academy of Pediatrics recommends a safe sleep environment to reduce the risk of all sleep-related deaths. This includes supine positioning; use of a firm, noninclined sleep surface; room sharing without bed sharing; and avoidance of soft bedding and overheating. Additional recommendations for SIDS risk reduction include human milk feeding; avoidance of exposure to nicotine, alcohol, marijuana, opioids, and illicit drugs; routine immunization; and use of a pacifier. New recommendations are presented regarding noninclined sleep surfaces, short-term emergency sleep locations, use of cardboard boxes as a sleep location, bed sharing, substance use, home cardiorespiratory monitors, and tummy time. Additional information to assist parents, physicians, and nonphysician clinicians in assessing the risk of specific bed-sharing situations is also included. The recommendations and strength of evidence for each recommendation are included in this policy statement. The rationale for these recommendations is discussed in detail in the accompanying technical report.

Does the duration and frequency of dummy (pacifier) use affect the development of speech?

BACKGROUND

The current literature suggests a link between dummy (or pacifier) use and a number of both positive and detrimental consequences. Positive consequences include soothing effect and protection from sudden infant death syndrome (SIDS), while negative ones include increased risk of otitis media and dental malformation. However, there is little research surrounding the impact of dummy use on the development of speech sounds.

AIMS

To investigate whether duration (in number of months) and frequency per day of dummy use have an individual or combined effect on the development of a child's speech, and if so, in what way.

METHODS & PROCEDURES

A total of 100 British-English children aged 24-61 months and growing up in the UK were recruited through nurseries, playgroups and by word of mouth. Their parents were asked to complete a questionnaire about the duration and frequency of dummy use and factors known to influence the development of speech. Following this, the children's speech was assessed using the phonology section of the Diagnostic Evaluation of Articulation and Phonology (DEAP). Analysis of the DEAP was conducted to determine the percentage of consonants correct, number of age-appropriate, delayed and atypical errors. Dummy use and speech outcome measures were then analysed qualitatively and quantitatively using mean and median group comparisons alongside multivariate generalized least squares and generalized negative binomial modelling approaches to test for significant associations.

OUTCOMES & RESULTS

The results showed that the majority of speech outcomes are not significantly associated with dummy use, however measured, in bivariate or multivariate analyses. However, there is a significant association between increased atypical errors and greater frequency of daytime dummy use. This association is strengthened by restricted sampling within the younger members of the sample, with this association not observable within children older than 38 months, the median sample age.

CONCLUSIONS & IMPLICATIONS

The evidence base for any effects of dummy use on speech is very small. Dummy use may increase the number of atypical speech errors a young child makes. However, only the frequency of daytime use seems relevant, not the duration or night-time use, and these errors may resolve over time. What this paper adds What is already known on this subject The use of a dummy with infants in Western countries is comparatively high (between 36-85%). A number of positive and detrimental consequences of dummy use have been documented in the literature; however, research on the effect of dummy use on speech development is significantly lacking. Past studies have included small sample sizes or used single measures of speech outcomes, which may not be specific enough to reveal how speech may be affected. Many speech and language therapists speculate that the use of a dummy could be contributing to many of the conditions they treat, yet this claim remains largely unsubstantiated. Clinical implications of this study The study suggests that only prolonged use of a dummy over several hours and during the day may start to show any impact on speech; even then, professionals need to be aware that the evidence base for any speech effects is very small. Clinicians and other professionals who parents consult on dummy use should make sure to provide both the pros and cons of dummy use, in order to enable parents to make an informed decision.

Oral Habits in Children With Orofacial Clefts: A Comparative Study

BACKGROUND AND AIM

Children with cleft lip and palate present with a wide range of dental and occlusal anomalies as a result of the cleft defect. These patients also present with oral habits which may affect their quality of life. The aim of this study was to compare the prevalence of oral habits in these children, with children without orofacial clefts.

METHODOLOGY

This was a cross-sectional comparative study comparing children with repaired cleft lip and/or palate aged 3 to 12 years, with children without orofacial clefts. Ethical approval for the study was obtained from the institutional review boards of both centers. Data collection was via interviewer administered questionnaires given to the parents/guardians of the children in each group. Data analysis was carried out using SPSS version 23. The level of significance was set at P < .05.

RESULTS

A total of 107 respondents participated in the study, comprising 53 children with repaired cleft lip and/or palate 54 children without orofacial clefts. The mean age for the children with Cleft lip and/or palate/ was 6.81 (standard deviation [SD] 1.898) years, while that for the control group was 7.78 (SD 1.68) years. Two oral habits recorded a significantly higher prevalence (P < .05) in the children with repaired clefts as compared to controls and these were lip sucking and bruxism. No significant difference in prevalence was recorded for all the other oral habits surveyed.

CONCLUSION

A significantly higher prevalence (P < .05) was observed in lip sucking and bruxism among children with cleft lip and palate, as compared to the children without orofacial clefts.

The Pacified Face: Early Embodiment Processes and the Use of Dummies

Few things affect us as much as facial expressions, as they inform us about others' feelings and intentions, thereby influencing our own emotions and behaviors. A substantial body of literature links the critical abilities of recognizing and understanding emotion displays with facial mimicry, a sensorimotor process involving rapid imitation of perceived expressions. For example, blocking or altering facial mimicry in adults leads to disruptions in judgments in emotion recognition or emotional language processing. The present review focuses on pacifier use in infancy, a common practice that has the potential to interfere with infants' facial movements in ways identical to laboratory paradigms designed to block facial mimicry. Despite this similarity and the widespread use of infant soothers, little is known about their long-term effects. Here we review studies exploring the psychological correlates and implications of pacifier use. In particular, we discuss how soothers may interfere with the development of social skills in infants and present evidence linking pacifier use with disrupted adults' mimicry of facial expressions displayed by infants. Other preliminary findings reveal negative correlations between the use of soothers and children's spontaneous facial mimicry as well as emotional competence of young adults. Such studies, although correlational, suggest that this widespread parenting practice may affect the development of social skills by influencing emotional coordination. We discuss the implications of these findings and propose avenues for future research that can provide insights into the role of embodied processes in the development of emotional competence and adult functioning.

Oral habits in Children with Cleft (Lip and) Palate: A Pilot Study

BACKGROUND/AIMS

This pilot study aimed to evaluate the occurrence of oral habits and non-nutritive sucking habits in children with cleft (lip and) palate (CL/P) between 0-12 years, compared to peers without CL/P.

METHODS

Children with CL/P (mean age 6.0 years, SD 2.80) were recruited from the Ghent University Hospital and compared to gender- and age-matched children without CL/P (mean age 5.8 years, SD 3.09). A self-report questionnaire was developed and given to the caregivers. To compare the occurrence of oral habits and non-nutritive sucking habits in children with and without CL/P, χ2 tests or Fisher's exact tests were used.

RESULTS

The present study revealed a significantly lower occurrence of non-nutritive sucking habits in children with CL/P. These children showed significantly less pacifier sucking; no significant difference was found regarding thumb or finger sucking nor regarding sucking on other objects. Additionally, the results showed that the occurrence of snoring was statistically significantly higher in children with CL/P.

CONCLUSION

Children with CL/P show less non-nutritive sucking habits, but more snoring compared to a control group without CL/P. Although further research regarding the oral habits in children with CL/P is necessary, cleft teams should give attention to the occurrence of oral habits.

Duration of Breastfeeding and Risk of SIDS: An Individual Participant Data Meta-analysis

CONTEXT

Sudden infant death syndrome (SIDS) is a leading cause of postneonatal infant mortality. Our previous meta-analyses showed that any breastfeeding is protective against SIDS with exclusive breastfeeding conferring a stronger effect.The duration of breastfeeding required to confer a protective effect is unknown.

OBJECTIVE

To assess the associations between breastfeeding duration and SIDS.

DATA SOURCES

Individual-level data from 8 case-control studies.

STUDY SELECTION

Case-control SIDS studies with breastfeeding data.

DATA EXTRACTION

Breastfeeding variables, demographic factors, and other potential confounders were identified. Individual-study and pooled analyses were performed.

RESULTS

A total of 2267 SIDS cases and 6837 control infants were included. In multivariable pooled analysis, breastfeeding for <2 months was not protective (adjusted odds ratio [aOR]: 0.91, 95% confidence interval [CI]: 0.68-1.22). Any breastfeeding ≥2 months was protective, with greater protection seen with increased duration (2-4 months: aOR: 0.60, 95% CI: 0.44-0.82; 4-6 months: aOR: 0.40, 95% CI: 0.26-0.63; and >6 months: aOR: 0.36, 95% CI: 0.22-0.61). Although exclusive breastfeeding for <2 months was not protective (aOR: 0.82, 95% CI: 0.59-1.14), longer periods were protective (2-4 months: aOR: 0.61, 95% CI: 0.42-0.87; 4-6 months: aOR: 0.46, 95% CI: 0.29-0.74).

LIMITATIONS

The variables collected in each study varied slightly, limiting our ability to include all studies in the analysis and control for all confounders.

CONCLUSIONS

Breastfeeding duration of at least 2 months was associated with half the risk of SIDS. Breastfeeding does not need to be exclusive to confer this protection.

Infant pacifiers for reduction in risk of sudden infant death syndrome

BACKGROUND

Sudden infant death syndrome (SIDS) has been most recently defined as the sudden unexpected death of an infant less than one year of age, with onset of the fatal episode apparently occurring during sleep, that remains unexplained after a thorough investigation, including the performance of a complete autopsy and a review of the circumstances of death and clinical history. Despite the success of several prevention campaigns, SIDS remains a leading cause of infant mortality. In 1994, a 'triple risk model' for SIDS was proposed that described SIDS as an event that results from the intersection of three factors: a vulnerable infant; a critical development period in homeostatic control (age related); and an exogenous stressor. The association between pacifier (dummy) use and reduced incidence of SIDS has been shown in epidemiological studies since the early 1990s. Pacifier use, given its low cost, might be a cost-effective intervention for SIDS prevention if it is confirmed effective in randomised controlled trials.

OBJECTIVES

To determine whether the use of pacifiers during sleep versus no pacifier during sleep reduces the risk of SIDS.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 2), MEDLINE via PubMed, Embase, and CINAHL to 16 March 2016. We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Published and unpublished controlled trials using random and quasi-random allocations of infants born at term and at preterm (less than 37 weeks' gestation) or with low birth weight (< 2500 g). Infants must have been randomised by one month' postmenstrual age. We planned to include studies reported only by abstracts, and cluster and cross-over randomised trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed studies from searches. We found no eligible studies.

MAIN RESULTS

We identified no randomised controlled trials examining infant pacifiers for reduction in risk of SIDS.

AUTHORS' CONCLUSIONS

We found no randomised control trial evidence on which to support or refute the use of pacifiers for the prevention of SIDS.

SIDS and Other Sleep-Related Infant Deaths: Evidence Base for 2016 Updated Recommendations for a Safe Infant Sleeping Environment

Approximately 3500 infants die annually in the United States from sleep-related infant deaths, including sudden infant death syndrome (SIDS), ill-defined deaths, and accidental suffocation and strangulation in bed. After an initial decrease in the 1990s, the overall sleep-related infant death rate has not declined in more recent years. Many of the modifiable and nonmodifiable risk factors for SIDS and other sleep-related infant deaths are strikingly similar. The American Academy of Pediatrics recommends a safe sleep environment that can reduce the risk of all sleep-related infant deaths. Recommendations for a safe sleep environment include supine positioning, use of a firm sleep surface, room-sharing without bed-sharing, and avoidance of soft bedding and overheating. Additional recommendations for SIDS risk reduction include avoidance of exposure to smoke, alcohol, and illicit drugs; breastfeeding; routine immunization; and use of a pacifier. New evidence and rationale for recommendations are presented for skin-to-skin care for newborn infants, bedside and in-bed sleepers, sleeping on couches/armchairs and in sitting devices, and use of soft bedding after 4 months of age. In addition, expanded recommendations for infant sleep location are included. The recommendations and strength of evidence for each recommendation are published in the accompanying policy statement, "SIDS and Other Sleep-Related Infant Deaths: Updated 2016 Recommendations for a Safe Infant Sleeping Environment," which is included in this issue.

Reasons for Pacifier Use and Non-Use in African-Americans: Does Knowledge of Reduced SIDS Risk Change Parents' Minds?

To investigate African-American parental reasons for pacifier use or non-use, and whether knowledge of the association with decreased SIDS risk changes decisions about pacifier use. We conducted focus groups and individual interviews with mothers. Grounded theory methodology was used. 83 mothers participated; 72.3 % of infants used pacifiers. Reasons for pacifier use included comfort/soothing, safety/SIDS, and preference over digit-sucking. Reasons for pacifier non-use included infant refusal, fear of attachment, nipple confusion, and germs. Many parents were unaware that pacifier use reduces SIDS risk; however, most parents of non-users did not think that this knowledge would have changed their decision. Reasons included skepticism about the pacifier-SIDS link. Many reasons underlie African-American parental decisions about pacifier use. Providers should provide information about the benefits of pacifiers. Establishing for parents any plausible link between the protective mechanism of pacifiers and SIDS pathophysiology may be important in promoting pacifier use.

Breastfeeding and dummy use have a protective effect on sudden infant death syndrome

We conducted a literature review on the effect of breastfeeding and dummy (pacifier) use on sudden infant death syndrome (SIDS). From 4343 abstracts, we identified 35 relevant studies on breastfeeding and SIDS, 27 on dummy use and SIDS and 59 on dummy use versus breastfeeding.

Conclusion

We found ample evidence that both breastfeeding and dummy use reduce the risk of SIDS. There has been a general reluctance to endorse dummy use in case it has a detrimental effect of breastfeeding. However, recent evidence suggests that dummy use might not be as harmful to breastfeeding as previously believed.

Using a pacifier to decrease sudden infant death syndrome: an emergency department educational intervention

Background. Pacifier use decreases the risk of sudden infant death syndrome (SIDS). An emergency department (ED) visit may provide an opportunistic ‘teachable moment’ for parents.

Objectives. To test the hypotheses (1) that caregivers were less familiar with the role of pacifiers in sudden infant death (SIDS) prevention than other recommendations, and (2) that an ED educational intervention would increase pacifier use in infants younger than six months, and (3) that otitis media would not occur more frequently in pacifier users.

Methods. We did an intervention-group-only longitudinal study in a county hospital ED. We measured pacifier use infants and baseline knowledge of SIDs prevention recommendations in caregivers. We followed up three months later to determine pacifier use, and 12 months later to determine episodes of otitis media.

Results. We analyzed data for 780 infants. Parents knew of advice against co-sleeping in 469/780 (60%), smoking in 660/776 (85%), and prone sleeping in 613/780 (79%). Only 268/777 (35%) knew the recommendation to offer a pacifier at bedtime. At enrollment 449/780 (58%) did not use a pacifier. Of 210/338 infants aged less than 6 months followed up 41/112 (37%) non-users had started using a pacifier at bedtime (NNT 3). Over the same period, 37/98 (38%) users had discontinued their pacifier. Otitis media did not differ between users and non-users at 12 months.

Conclusion. Caregiver knowledge of the role of pacifiers in SIDS prevention was less than for other recommendations. Our educational intervention appeared to increase pacifier use. Pacifier use was not associated with increased otitis media.

Dummy (pacifier) use and sudden infant death syndrome: potential advantages and disadvantages

The large decline in deaths due to the sudden infant death syndrome (SIDS) in the last 20 years in many countries is largely due to risk-reduction advice resulting from observational studies that examined the relationship between infant care practices and SIDS. Most of this advice remains largely uncontroversial and educators and researchers in this field are in agreement as to the specific recommendations that should be given to parents and health professionals. However, advice surrounding the apparent protective effect of dummies (also known as pacifiers) has been controversial. Several systematic reviews have demonstrated a strong association between the lack of a pacifier being used by the infant for the final sleep and SIDS, but it is not clear how pacifiers confer protection or if this is a marker for something as yet unmeasured. The Epidemiology and Physiology Working Groups of the International Society for the Study and Prevention of Perinatal and Infant Death (ISPID) are comprised of leading SIDS researchers with an objective to provide evidence-based position statements surrounding the factors associated with SIDS (http://www.ispid.org/) and risk-reduction strategies. The evidence, discussion and conclusions from these working groups regarding dummies (pacifiers) are described below to help inform this debate and describe the future evidence required so that we might find a common recommendation about dummies (pacifiers) and SIDS.

Maternal smoking and increased risk of sudden infant death syndrome: a meta-analysis

Maternal smoking is detrimental to the development of fetuses and neonates. This meta-analysis was performed to measure the accumulated association of sudden infant death syndrome (SIDS) risk with both prenatal and postnatal maternal smoking. The odds ratio (OR) corresponding to the 95% confidence interval (CI) was used to assess the associations between maternal smoking and SIDS risk. The statistical heterogeneity among studies was assessed with the Q-test and I(2) statistics. The data for this meta-analysis were available from 35 case-control studies. The prenatal and postnatal maternal smoking was associated with a significantly increased risk of SIDS (OR=2.25, 95% CI=2.03-2.50 for prenatal maternal smoking analysis, and OR=1.97, 95% CI=1.77-2.19 for postnatal maternal smoking analysis, respectively) by random effects model. After stratified analyses, regardless of prenatal or postnatal smoking, heavy cigarette consumption increased the risk of SIDS and significantly elevated SIDS risk was found to be associated with co-sleeping with postnatal smoking mothers. Our results suggested that maternal smoking were associated with elevated SIDS risk, the effects were dose-dependent. In addition, SIDS risk was significantly increased in infants co-sleeping with postnatal smoking mothers.

Scientific consensus forum to review the evidence underpinning the recommendations of the Australian SIDS and Kids Safe Sleeping Health Promotion Programme--October 2010

This paper summarises a 1-day scientific consensus forum that reviewed the evidence underpinning the Australian SIDS and Kids Safe Sleeping Health Promotion Programme. The focus was on each of the potentially modifiable risk factors for sudden unexpected deaths in infancy, including sudden infant death syndrome (SIDS) and fatal sleeping accidents. In particular infant sleeping position, covering of the face, exposure to cigarette smoke, room sharing, unsafe sleeping environments, bed sharing, immunisation, breastfeeding, pacifier use and Indigenous issues were discussed in depth. The participants recommended that future 'Reducing the Risk' campaign messages should focus on back to sleep, face uncovered, avoidance of cigarette smoke before and after birth, safe sleeping environment, room sharing and sleeping baby in own cot.

SIDS and other sleep-related infant deaths: expansion of recommendations for a safe infant sleeping environment

Despite 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 for sleep in a nonprone position, this decline has plateaued in recent years. Concurrently, other causes of sudden unexpected infant death occurring during sleep (sleep-related deaths), including suffocation, asphyxia, and entrapment, and ill-defined or unspecified causes of death have increased in incidence, particularly since the AAP published its last statement on SIDS in 2005. It has become increasingly important to address these other causes of sleep-related infant death. Many of the modifiable and nonmodifiable risk factors for SIDS and suffocation are strikingly similar. The AAP, therefore, is expanding its recommendations from being only SIDS-focused to focusing on a safe sleep environment that can reduce the risk of all sleep-related infant deaths including SIDS. The recommendations described in this report include supine positioning, use of a firm sleep surface, breastfeeding, room-sharing without bed-sharing, routine immunization, consideration of a pacifier, and avoidance of soft bedding, overheating, and exposure to tobacco smoke, alcohol, and illicit drugs. The rationale for these recommendations is discussed in detail in this technical report. The recommendations are published in the accompanying "Policy Statement--Sudden Infant Death Syndrome and Other Sleep-Related Infant Deaths: Expansion of Recommendations for a Safe Infant Sleeping Environment," which is included in this issue (www.pediatrics.org/cgi/doi/10.1542/peds.2011-2220).

Bed-sharing among six-month-old infants in western Sweden

AIM

In spite of several reports of an increased risk of sudden infant death syndrome (SIDS) in connection with bed-sharing, it is not an uncommon practice. The aim of this study was to examine bed-sharing at 6 months of age and the factors that are associated with bed-sharing.

METHODS

Our cohort comprised 8176 randomly chosen families. At 6 month of age, the families received an invitation to the study, with a questionnaire, which was completed by 5605 families (response rate 68.5%).

RESULTS

Of the families, 19.8% bed-shared. In the multivariate analysis, we found a correlation between breast-feeding and bed-sharing (breast-feeding at 6 months: OR 1.94; 95% CI 1.56, 2.41). Moreover, we found an association with 3+ nightly awakenings at 6 months (2.70; 2.20, 3.32). It was more common to share a bed if the parent was single (2.04; 1.19, 3.51) and less common if the infant was bottle-fed in the first week (0.70; 0.54, 0.90). Never using a pacifier was associated with a higher frequency of bed-sharing.

CONCLUSION

We found a correlation between breast-feeding and bed-sharing as well as between sleeping problems and a single parent. A lower percentage of infants sleeping in the parental bed were seen in association with formula feeding in the first week after birth.

Cardiovascular control during sleep in infants: Implications for Sudden Infant Death Syndrome

In infants the cardiorespiratory system undergoes significant functional maturation after birth and these changes are sleep-state dependent. Given the immaturity of these systems it is not surprising that infants are at risk of cardiorespiratory instability, especially during sleep. A failure of cardiovascular control mechanisms in particular is believed to play a role in the final event of Sudden Infant Death Syndrome (SIDS). The "triple risk model" describes SIDS as an event that results from the intersection of three overlapping factors: (1) a vulnerable infant, (2) a critical development period in homeostatic control, and (3) an exogenous stressor. This review summarises normal development of cardiovascular control during sleep in infants and describes the association of impaired cardiovascular control with the three overlapping factors proposed to be involved in SIDS pathogenesis.

Narratives of deprivation: Women's life stories around Maori sudden infant death syndrome

Maori babies in Aotearoa/New Zealand die of Sudden Infant Death Syndrome (SIDS) at over five times the rate of their non-Maori peers. Research and health promotion around modifiable risk factors has produced only a small improvement in this situation since the mid-1990s. This paper reports on life story interviews, conducted between 2002 and 2004, with nineteen mothers of Maori infants who have died of SIDS. Potential participants were identified and accessed with the support of the national Maori SIDS Prevention Programme care-workers, in both urban and rural locations throughout both main islands of New Zealand. The paper articulates, in a thematic fashion, the bereaved mothers' experiences of alienation, marginalisation and exclusion, as a testimony of lives lived under conditions of serious deprivation in an affluent society. Constructing these experiences as non-modifiable risk factors hinders the development of policy and health promotion interventions that could improve the conditions in which Maori mothers live and raise their babies. It is argued that new approaches that target those whose lives are described here and build on the WHO Social Determinants of Health framework are vital to the efforts of New Zealanders to attain health equity and stem the tide of devastating and preventable loss of Maori babies to SIDS.

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

OBJECTIVES

To investigate the factors associated with sudden infant death syndrome (SIDS) from birth to age 2 years, whether recent advice has been followed, whether any new risk factors have emerged, and the specific circumstances in which SIDS occurs while cosleeping (infant sharing the same bed or sofa with an adult or child).

DESIGN

Four year population based case-control study. Parents were interviewed shortly after the death or after the reference sleep (within 24 hours) of the two control groups.

SETTING

South west region of England (population 4.9 million, 184 800 births).

PARTICIPANTS

80 SIDS infants and two control groups weighted for age and time of reference sleep: 87 randomly selected controls and 82 controls at high risk of SIDS (young, socially deprived, multiparous mothers who smoked).

RESULTS

The median age at death (66 days) was more than three weeks less than in a study in the same region a decade earlier. Of the SIDS infants, 54% died while cosleeping compared with 20% among both control groups. Much of this excess may be explained by a significant multivariable interaction between cosleeping and recent parental use of alcohol or drugs (31% v 3% random controls) and the increased proportion of SIDS infants who had coslept on a sofa (17% v 1%). One fifth of SIDS infants used a pillow for the last sleep (21% v 3%) and one quarter were swaddled (24% v 6%). More mothers of SIDS infants than random control infants smoked during pregnancy (60% v 14%), whereas one quarter of the SIDS infants were preterm (26% v 5%) or were in fair or poor health for the last sleep (28% v 6%). All of these differences were significant in the multivariable analysis regardless of which control group was used for comparison. The significance of covering the infant's head, postnatal exposure to tobacco smoke, dummy use, and sleeping in the side position has diminished although a significant proportion of SIDS infants were still found prone (29% v 10%).

CONCLUSIONS

Many of the SIDS infants had coslept in a hazardous environment. The major influences on risk, regardless of markers for socioeconomic deprivation, are amenable to change and specific advice needs to be given, particularly on use of alcohol or drugs before cosleeping and cosleeping on a sofa.

The pacifier debate

A variety of studies have indicated that pacifier use lowers the risk of SIDS. Many observational studies have demonstrated a negative association between pacifier use and breastfeeding duration. However, observational studies cannot be used to determine whether the pacifier is the real cause of breastfeeding cessation. Evidence for causation can be better supplied by randomised controlled trials (RCTs). Three RCTs have been conducted on the relationship between pacifiers and breastfeeding, but each study has limitations, implying that the evidence of not causal effect can be questionated. We have recently presented the results of a large RCT which demonstrated that in mothers who are successfully breastfeeding at 2 weeks, the recommendation to offer a pacifier does not modify the prevalence of exclusive and any breastfeeding at different ages or the duration of lactation. It is therefore important that lactation consultants and international agencies reexamine their staunch position to discourage the use of pacifiers on the basis of a supposed adverse effect on the success and duration of breastfeeding.

Pacifier use as a risk factor for reduction in breastfeeding duration: a systematic review

This systematic review of literature proposes to establish whether pacifier use is a risk factor for a reduction in the duration of breastfeeding. A search of the Medline and Lilacs databases was carried out for articles published between 1996 and 2006 using the following descriptors: "breastfeeding" and "pacifier". Articles were excluded if they: had no open access abstracts; did not contain estimators testing the degree of association between breastfeeding duration and pacifier use; involved a follow-up loss of greater than 20%; were written in languages other than Portuguese, English and Spanish; covered specific population categories, such as pre-term babies or mothers who experienced difficulty breastfeeding; or were based on information provided by the mother or a health care professional. Nineteen articles were chosen according to the criteria outlined above; of these, one was a randomized clinical trial, eleven were prospective cohort studies and seven were cross sectional studies. The review concludes that pacifier use is a risk factor for breastfeeding duration, although the performance mechanism remains obscure. Other risk factors relate to the children, their parents and the hospital care they receive regarding the early interruption of breastfeeding. There is a need to standardize the methodology for investigating the association between pacifier use and breastfeeding duration, in order to provide scientific knowledge on this subject.

Pacifier use does not alter the frequency or duration of spontaneous arousals in sleeping infants

OBJECTIVE

It has been reported that pacifiers might reduce the risk of SIDS by favouring infants' arousability from sleep. We evaluated the influence of a pacifier on the frequency and duration of spontaneous arousals in healthy infants.

METHODS

Polygraphic recordings were performed in 14 infants with an age of 51.7+/-19.9 days (means+/-SD) who regularly used a pacifier during sleep. Cortical and subcortical arousals were scored according to the recommendations of the "International Paediatric Work Group on Arousals." The number of arousals per 10-min-period and the duration of arousals were determined for periods of pacifier use as well as for periods after pacifier dislodgement and were compared with the data of 10 control infants (age 49.8+/-16.5 days) who never used a pacifier.

RESULTS

Altogether, 211 arousals in pacifier users and 225 arousals in non-users were scored. In pacifier users, 2.0+/-1.6 arousals per 10-min-period with a duration of 12.2+/-3.0 s occurred during pacifier use, and 1.7+/-1.6 arousals per 10-min-period with a duration of 12.2+/-3.1s occurred during periods without pacifier. In pacifier non-users, 2.3+/-1.2 arousals per 10-min-period (duration 13.9+/-2.9s) were scored. The results did not show a significant difference concerning frequency and duration of spontaneous arousals between pacifier users and non-users.

CONCLUSIONS

Our findings suggest that factors other than arousal mechanisms might be responsible for the efficacy of pacifiers in SIDS prophylaxis.

Pacifier use: what makes mothers change their mind?

AIM

To find out the reasons for mothers to either use or not use a pacifier and to find out the mother's reasons for changing their mind.

METHOD

We analysed the data of 174 mother-infant pairs by means of a semistructured questionnaire performed shortly after birth, and at the age of 7 weeks and 5 months, respectively.

RESULTS

The main reason for mothers primarily refusing a pacifier was their concern about malformation of the teeth or jaw. Until the end of the fifth month, 31% of the mothers changed their mind about pacifier use. Mothers primarily refusing a pacifier introduced a pacifier due to the need of soothing the infant. Mothers, who initially intended to use a pacifier, changed their mind due to rejection by the infant. The prevalence of pacifier use at the age of 5 months was 78%. The majority of mothers (69%) introduced the pacifier during the first week of life.

CONCLUSION

About one third of mothers had changed their mind about pacifier use, either because of rejection by the infant or the need of settling. Breastfeeding mothers require more and better information concerning the appropriate time of pacifier onset.

Sudden infant death syndrome

Despite declines in prevalence during the past two decades, sudden infant death syndrome (SIDS) continues to be the leading cause of death for infants aged between 1 month and 1 year in developed countries. Behavioural risk factors identified in epidemiological studies include prone and side positions for infant sleep, smoke exposure, soft bedding and sleep surfaces, and overheating. Evidence also suggests that pacifier use at sleep time and room sharing without bed sharing are associated with decreased risk of SIDS. Although the cause of SIDS is unknown, immature cardiorespiratory autonomic control and failure of arousal responsiveness from sleep are important factors. Gene polymorphisms relating to serotonin transport and autonomic nervous system development might make affected infants more vulnerable to SIDS. Campaigns for risk reduction have helped to reduce SIDS incidence by 50-90%. However, to reduce the incidence even further, greater strides must be made in reducing prenatal smoke exposure and implementing other recommended infant care practices. Continued research is needed to identify the pathophysiological basis of SIDS.

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.

Modifiable risk factors, sleep environment, developmental physiology and common polymorphisms: understanding and preventing sudden infant deaths

Unexpected death in infancy may be a consequence of recognisable pathophysiological processes, or may remain unexplained after thorough investigation. We review the appropriate investigations that should be performed after unexpected infant deaths, and the recent changes to UK law that will make such investigations mandatory from 2008. Current knowledge of the epidemiology and pathophysiology of unexpected infant deaths, together with knowledge of infant developmental physiology leads to an emphasis on the importance of a range of potential gene-environment interactions occurring in vulnerable infants at vulnerable stages of their development.

Pacifiers: A microbial reservoir

The permanent contact between the nipple part of pacifiers and the oral microflora offers ideal conditions for the development of biofilms. This study assessed the microbial contamination on the surface of 25 used pacifier nipples provided by day-care centers. Nine were made of silicone and 16 were made of latex. The biofilm was quantified using direct staining and microscopic observations followed by scraping and microorganism counting. The presence of a biofilm was confirmed on 80% of the pacifier nipples studied. This biofilm was mature for 36% of them. Latex pacifier nipples were more contaminated than silicone ones. The two main genera isolated were Staphylococcus and Candida. Our results confirm that nipples can be seen as potential reservoirs of infections. However, pacifiers do have some advantages; in particular, the potential protection they afford against sudden infant death syndrome. Strict rules of hygiene and an efficient antibiofilm cleaning protocol should be established to answer the worries of parents concerning the safety of pacifiers.

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 infant's 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.

Should pacifiers be recommended to prevent sudden infant death syndrome?

OBJECTIVES

Our aim was to review the evidence for a reduction in the risk of sudden infant death syndrome (SIDS) with pacifier ("dummy" or "soother") use, to discuss possible mechanisms for the reduction in SIDS risk, and to review other possible health effects of pacifiers.

RESULTS

There is a remarkably consistent reduction of SIDS with pacifier use. The mechanism by which pacifiers might reduce the risk of SIDS is unknown, but several mechanisms have been postulated. Pacifiers might reduce breastfeeding duration, but the studies are conflicting.

CONCLUSIONS

It seems appropriate to stop discouraging the use of pacifiers. Whether it is appropriate to recommend pacifier use in infants is open to debate.

Use of a dummy (pacifier) during sleep and risk of sudden infant death syndrome (SIDS): population based case-control study

OBJECTIVES

To examine the association between use of a dummy (pacifier) during sleep and the risk of sudden infant death syndrome (SIDS) in relation to other risk factors.

DESIGN

Population based case-control study.

SETTING

Eleven counties in California.

PARTICIPANTS

Mothers or carers of 185 infants whose deaths were attributed to SIDS and 312 randomly selected controls matched for race or ethnicity and age.

MAIN OUTCOME MEASURE

Use of a dummy during sleep determined through interviews.

RESULTS

The adjusted odds ratio for SIDS associated with using a dummy during the last sleep was 0.08 (95% confidence interval 0.03 to 0.21). Use was associated with a reduction in risk in every category of sociodemographic characteristics and risk factors examined. The reduced risk associated with use seemed to be greater with adverse sleep conditions (such as sleeping prone or on side and sleeping with a mother who smoked), although the observed interactions were not significant. In addition, use of a dummy may reduce the impact of other risk factors for SIDS, especially those related to adverse sleep environment. For example, infants who did not use a dummy and slept prone or on their sides (v on their back) had an increased risk of SIDS (2.61, 1.56 to 4.38). In infants who used dummies, there was no increased risk associated with sleeping position (0.66, 0.12 to 3.59). While cosleeping with a mother who smoked was also associated with increased risk of SIDS among infants who did not use a dummy (4.5, 1.3 to 15.1), there was no such association among those who did (1.1, 0.1 to 13.4).

CONCLUSIONS

Use of a dummy seems to reduce the risk of SIDS and possibly reduces the influence of known risk factors in the sleep environment.

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.

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 infant's need for sucking is highest. For breastfed infants, pacifiers should be introduced after breastfeeding has been well established.

International Child Care Practices study: breastfeeding and pacifier use

Although the Baby-Friendly Hospital Initiative advises that no pacifiers be given to breastfeeding infants, both breastfeeding and pacifier use may protect against sudden infant death syndrome. The International Child Care Practice Study data set on child care practices associated with sudden infant death syndrome risk from 21 centers in 17 countries was used to describe infant-feeding practices and pacifier use and assess factors associated with breastfeeding. At approximately 3 months of age, rates of breastfeeding only (4%-80%) and pacifier use(12.5%-71%) varied between centers. Pacifier use was negatively associated with breastfeeding, and a dose-response effect was noted. Other negative (multiple birth, smoking by mother) and positive (intention to breastfeed, bed sharing, mothers' education) associations with breastfeeding only were identified. Although causality should not be inferred, these associations are consistent with previous studies. Advice on pacifiers should include potential benefits as well as risks.

Detection of specific antibodies in cord blood, infant and maternal saliva and breast milk to staphylococcal toxins implicated in sudden infant death syndrome (SIDS)

The common bacterial toxins hypothesis of sudden infant death syndrome (SIDS) is that nasopharyngeal bacterial toxins can trigger events leading to death in infants with absent/low levels of antibody that can neutralise the toxins. The aim of this study was to investigate nasopharyngeal carriage of Staphylococcus aureus and determine levels of immunity in the first year of life to toxic shock syndrome toxin (TSST-1) and staphylococcal enterotoxin C (SEC). Both toxins have been implicated in SIDS cases. Seventy-three mothers and their infants (39 males and 34 females) were enrolled onto the study. The infants had birth dates spread evenly throughout the year. In infants, S. aureus carriage decreased significantly with age (P<0.001). Between 40% and 50% of infants were colonised with S. aureus in the first three months of life and 49% of the isolates produced one or both of the staphylococcal toxins. There was a significant correlation between nasopharyngeal carriage of S. aureus in mothers and infants in the three months following the birth (P<0.001). Carriage of S. aureus in infants and their mothers was not significantly associated with levels of antibody to TSST-1 or SEC in cord blood, adult saliva or breast milk. Infants colonised by S. aureus had higher levels of salivary IgA to TSST-1 than infants who were culture negative. Analysis of cord blood samples by a quantitative ELISA detected IgG bound to TSST-1 and SEC in 95.5% and 91.8% of cases respectively. There was a marked variation in levels of maternal IgG to both TSST-1 and SEC among cord blood samples. Maternal age, birth weight, and seasonality significantly affected the levels of IgG binding to TSST-1 or SEC. Analysis of infant saliva samples detected IgA to TSST-1 and SEC in the first month after birth; 11% of samples tested positive for salivary IgA to TSST-1 and 5% for salivary IgA to SEC. By the age of two months these proportions had increased to 36% and 33% respectively. More infants who used a dummy tested positive for salivary IgA to TSST-1 compared to infants who did not use a dummy. Levels of IgA to TSST-1 and SEC detected in the breast-milk samples varied greatly among mothers. There was a trend for infants receiving breast milk with low levels of antibody to TSST-1 or SEC to have higher levels of salivary antibody to the toxins. In conclusion, passive immunity to toxins implicated in SIDS cases varies greatly among infants. Infants are able to mount an active mucosal immune response to TSST-1 and SEC in the first month of life.

Pacifier use modifies infant's cardiac autonomic controls during sleep

OBJECTIVE

The risk for sudden infant death (SIDS) was postulated to decrease with the use of a pacifier and by conditions increasing parasympathetic tonus during sleep. We evaluated the influence of a pacifier on cardiac autonomic controls in healthy infants.

STUDY DESIGN

Thirty-four healthy infants were studied polygraphically during one night: 17 infants regularly used a pacifier during sleep and 17 never used a pacifier. Thumb users or occasional pacifier users were not included in the study. The infants were recorded at a median age of 10 weeks (range 6-18 weeks). Autonomic nervous system (ANS) was evaluated by spectral analysis of the heart rate (HR). The high frequency component of HR spectral analysis reflected parasympathetic tonus and the low frequency on high frequency ratio corresponded to the sympathovagal balance.

RESULTS

Most infants (63.6%) lost their pacifier within 30 min of falling asleep. Sucking periods were associated with increases in cardiac sympathovagal balance. During non-sucking periods, in both REM and NREM sleep, infants using a pacifier were characterized by lower sympathetic activity and higher parasympathetic tonus compared with non-pacifier users.

CONCLUSIONS

The use of pacifiers modifies cardiac autonomic controls during both sucking and non-sucking sleep periods. Non-nutritive sucking could regulate autonomic control in infants. These findings could be relevant to mechanisms implicated in the occurrence of sudden infant deaths during sleep.