Bed-sharing and the infant's thermal environment in the home setting

Death from Failed Protection? An Evolutionary-Developmental Theory of Sudden Infant Death Syndrome

Sudden infant death syndrome (SIDS) has been mainly described from a risk perspective, with a focus on endogenous, exogenous, and temporal risk factors that can interact to facilitate lethal outcomes. Here we discuss the limitations that this risk-based paradigm may have, using two of the major risk factors for SIDS, prone sleep position and bed-sharing, as examples. Based on a multipronged theoretical model encompassing evolutionary theory, developmental biology, and cultural mismatch theory, we conceptualize the vulnerability to SIDS as an imbalance between current physiologic-regulatory demands and current protective abilities on the part of the infant. From this understanding, SIDS appears as a developmental condition in which competencies relevant to self-protection fail to develop appropriately in the future victims. Since all of the protective resources in question are bound to emerge during normal infant development, we contend that SIDS may reflect an evolutionary mismatch situation-a constellation in which certain modern developmental influences may overextend the child's adaptive (evolutionary) repertoire. We thus argue that SIDS may be better understood if the focus on risk factors is complemented by a deeper appreciation of the protective resources that human infants acquire during their normal development. We extensively analyze this evolutionary-developmental theory against the body of epidemiological and experimental evidence in SIDS research and thereby also address the as-of-yet unresolved question of why breastfeeding may be protective against SIDS.

Hyperthermia and Heat Stress as Risk Factors for Sudden Infant Death Syndrome: A Narrative Review

BACKGROUND AND OBJECTIVES

Heat stress and hyperthermia are common findings in sudden infant death syndrome (SIDS) victims. It has been suggested that thermal stress can increase the risk of SIDS directly via lethal hyperthermia or indirectly by altering autonomic functions. Major changes in sleep, thermoregulation, cardiovascular function, and the emergence of circadian functions occur at the age at which the risk of SIDS peaks-explaining the greater vulnerability at this stage of development. Here, we review the literature data on (i) heat stress and hyperthermia as direct risk factors for SIDS, and (ii) the indirect effects of thermal loads on vital physiological functions.

RESULTS

Various situations leading to thermal stress (i.e., outdoors temperatures, thermal insulation from clothing and bedding, the prone position, bed-sharing, and head covering) have been analyzed. Hyperthermia mainly results from excessive clothing and bedding insulation with regard to the ambient thermal conditions. The appropriate amount of clothing and bedding thermal insulation for homeothermia requires further research. The prone position and bed-sharing do not have major thermal impacts; the elevated risk of SIDS in these situations cannot be explained solely by thermal factors. Special attention should be given to brain overheating because of the head's major role in body heat losses, heat production, and autonomic functions. Thermal stress can alter cardiovascular and respiratory functions, which in turn can lead to life-threatening events (e.g., bradycardia, apnea with blood desaturation, and glottal closure). Unfortunately, thermal load impairs the responses to these challenges by reducing chemosensitivity, arousability, and autoresuscitation. As a result, thermal load (even when not lethal directly) can interact detrimentally with vital physiological functions.

CONCLUSIONS

With the exception of excessive thermal insulation (which can lead to lethal hyperthermia), the major risk factors for SIDS appears to be associated with impairments of vital physiological functions when the infant is exposed to thermal stress.

Functional links between thermoregulation and sleep in children with neurodevelopmental and chronic health conditions

The bi-directional relationship between sleep and wake is recognized as important for all children. It is particularly consequential for children who have neurodevelopmental disorders (NDDs) or health conditions which challenge their sleep and biological rhythms, and their ability to maintain rhythms of participation in everyday activities. There are many studies which report the diverse reasons for disruption to sleep in these populations. Predominantly, there is focus on respiratory, pharmaceutical, and behavioral approaches to management. There is, however, little exploration and explanation of the important effects of body thermoregulation on children's sleep-wake patterns, and associated behaviors. Circadian patterns of sleep-wake are dependent on patterns of body temperature change, large enough to induce sleep preparedness but remaining within a range to avoid sleep disturbances when active thermoregulatory responses against heat or cold are elicited (to maintain thermoneutrality). Additionally, the subjective notion of thermal comfort (which coincides with the objective concept of thermoneutrality) is of interest as part of general comfort and associated behavioral responses for sleep onset and maintenance. Children's thermoregulation and thermal comfort are affected by diverse biological functions, as well as their participation in everyday activities, within their everyday environments. Hence, the aforementioned populations are additionally vulnerable to disruption of their thermoregulatory system and their capacity for balance of sleep and wakefulness. The purpose of this paper is to present hitherto overlooked information, for consideration by researchers and clinicians toward determining assessment and intervention approaches to support children's thermoregulation functions and promote their subjective thermal comfort, for improved regulation of their sleep and wake functions.

Oral-Health-Related Quality of Life and Cosleeping: The Role of Nocturnal Breastfeeding

The purpose of this paper is to analyse the association between cosleeping and the number of breastfeeding sessions in infants, OHRQoL of the child and the family, and the DMFT Child’s index. The sample comprised 273 children (2–4 years old). In addition to the clinical examination of the child to assess the DMFT Index, the mother was requested to complete a questionnaire to collect data about the breastfeeding practice, diet, dental hygiene, dental check-ups, quality of the child’s oral life, and family impact (ECOHIS Scale). The children’s OHRQoL is positively correlated with number of night-time breastfeeding sessions at 12 months (r² = 0.40 **), DMFT index (r² = 0.60 **), impact family (r² = 0.65 **), and duration of cosleeping (r² = 0.36 **). The moderating effect explained 41% of OHRQoL; the interaction between the number of breastfeeding sessions at 18 months and the DMFT index significantly increased the coefficient of determination. A longer practice time for cosleeping was associated with an increase in breastfeeding sessions, a higher impact on OHRQoL, a higher family impact, and a higher DMFT index. More than three night-time breastfeeding sessions moderate the relationship between the DMFT index and the child’s OHRQoL.

Bed sharing versus no bed sharing for healthy term neonates

BACKGROUND

There is great global variation in the sleeping arrangements for healthy newborn infants. Bed sharing is a type of sleeping practice in which the sleeping surface (e.g. bed, couch or armchair, or some other sleeping surface) is shared between the infant and another person. The possible physiological benefits include better oxygen and cardiopulmonary stability, fewer crying episodes, less risk of hypothermia, and a longer duration of breastfeeding. On the other hand, the most important harmful effect of bed sharing is that it may increase the risk of sudden infant death syndrome (SIDS). Studies have found conflicting evidence regarding the safety and efficacy of bed sharing during infancy.

OBJECTIVES

To evaluate the efficacy and safety of bed sharing, started during the neonatal period, on breastfeeding status (exclusive and total duration of breastfeeding), incidence of SIDS, rates of hypothermia, neonatal and infant mortality, and long-term neurodevelopmental outcomes.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2020, Issue 7) in the Cochrane Library; MEDLINE via PubMed (1966 to 23 July 2020), CINAHL (1982 to 23 July 2020), and LILACS (1980 to 23 July 2020). We also searched clinical trials databases, and the reference lists of retrieved articles, for randomised controlled trials (RCTs) and quasi-RCTS.

SELECTION CRITERIA

We planned to include RCTs or quasi-RCTs (including cluster-randomised trials) that included term neonates initiated on bed sharing within 24 hours of birth (and continuing to bed share with the mother in the first four weeks of life, followed by a variable time period thereafter), and compared them to a 'no bed sharing' group.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane. We planned to use the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Our search strategy yielded 6231 records. After removal of duplicate records, we screened 2745 records by title and abstract. We excluded 2739 records that did not match our inclusion criteria. We obtained six full-text studies for assessment. These six studies did not meet the eligibility criteria and were excluded.

AUTHORS' CONCLUSIONS

We did not find any studies that met our inclusion criteria. There is a need for RCTs on bed sharing in healthy term neonates that directly assess efficacy (i.e. studies in a controlled setting, like hospital) or effectiveness (i.e. studies conducted in community or home settings) and safety. Future studies should assess outcomes such as breastfeeding status and risk of SIDS. They should also include neonates from high-income countries and low- and middle-income countries, especially those countries where bed sharing is more prevalent because of cultural practices (e.g. Asian countries).

The influence of bed-sharing on infant physiology, breastfeeding and behaviour: A systematic review

This review aimed to better understand the underlying physiology of the risks and benefits of bed-sharing. Eight databases were searched using terms relating to adult-infant/baby, bed-sharing/co-sleeping combined with outcome terms for physiology, sleep, cardiovascular, respiratory, temperature and behaviour. Of 836 papers identified, 59 papers representing 48 cohorts met inclusion criteria. Objective data using various methodologies were available in 27 papers and subjective data in 32 papers. Diverse measures were reported using variable definitions of bed-sharing. Identified physiological and behavioural differences between bed-sharing and cot-sleeping included increased behavioural arousals, warmer in-bed temperatures and increased breastfeeding duration in bedshare infants as well as differences in infant overnight sleep architecture, cardiorespiratory control and cortisol responses to stress. We concluded that many differences are context-specific, and dependent on the subjective view of the parents and their cultural values. Objective risk arises if the infant is unable to mount an appropriate physiological or behavioural response to their micro-environment. More studies in the bed-sharing setting are needed to identify infant risk, the potential benefits of a safer environment, and how bed-sharing interacts with infant care practices other than sleep.

The Pēpi-Pod study: Overnight video, oximetry and thermal environment while using an in-bed sleep device for sudden unexpected death in infancy prevention

AIM

The aim of this study was to identify the potential risks and benefits of sleeping infants in a Pēpi-Pod distributed to families with high risk of sudden unexpected death in infancy compared to a bassinet.

METHODS

Forty-five mostly indigenous Māori mothers who were referred by local health providers to receive a Pēpi-Pod were surveyed at recruitment, 1 and 3 months. A sleep study at 1 month included infrared video, oximetry and temperature measures.

RESULTS

When compared with 89 historical bassinet controls, an intention-to-treat analysis of questionnaires showed no increase in direct bed sharing but demonstrated significantly less sharing of the maternal bedroom at both interviews, with the majority of those not sleeping in the maternal bedroom, actually sleeping in the living room. The 1 month 'as-used' analysis showed poorer maternal sleep quality. The 'as-used' analysis of video data (24 Pēpi-Pod and 113 bassinet infants) also showed no increase in direct bed sharing, head covering or prone/side sleep position. Differences in oxygen saturation were not significant, but heart rate was higher in the Pēpi-Pod infants by 8.37 bpm (95% confidence interval 4.40, 12.14). Time in the thermal comfort zone was not different between groups despite Pēpi-Pod infants being situated in significantly warmer rooms.

CONCLUSIONS

Overall, we found that most differences in infant risk behaviours in a Pēpi-Pod compared to a bassinet were small, with confidence intervals excluding meaningful differences. We noted poorer maternal sleep quality at 1 month. Higher infant heart rates in the Pēpi-Pod group may be related to higher room temperatures. The Pēpi-Pod appears physiologically safe but is associated with lower reported maternal sleep quality.

Physiological stability in an indigenous sleep device: a randomised controlled trial

OBJECTIVE

To compare overnight oxygen saturation, heart rate and the thermal environment of infants sleeping in an indigenous sleep device (wahakura) or bassinet to identify potential risks and benefits.

DESIGN

Randomised controlled trial.

SETTING

Family homes in low socio-economic areas in New Zealand.

PATIENTS

200 mainly Māori mothers and their infants.

INTERVENTIONS

Participants received a wahakura or bassinet from birth.

MAIN OUTCOME MEASURES

Overnight oximetry, heart rate and temperature at 1 month.

RESULTS

Intention-to-treat analysis for 83 bassinet and 84 wahakura infants showed no significant differences between groups for the mean time oxygen saturation (SpO₂) was less than 94% (0.54 min, 95% CI -1.36 to 2.45) or less than 90% (0.22 min, 95% CI -0.56 to 1.00), the mean number of SpO₂ dips per hour >5% (-0.19, 95% CI -3.07 to 2.69) or >10% (-0.41, 95% CI -1.63 to 0.81), mean heart rate (1.99 beats/min, 95% CI -1.02 to 4.99), or time shin temperature >36°C (risk ratio (RR): 0.63, 95% CI 0.13 to 2.99) or <34°C (RR: 0.89, 95% CI 0.61 to 1.30). A per-protocol analysis of 45 bassinet and 26 wahakura infants and an as-used analysis of 104 infants in a bassinet and 48 in a wahakura found no significant differences between groups for all outcome measures.

CONCLUSIONS

This indigenous sleep device is at least as safe as the currently recommended bassinet, which supports its use as a sleep environment that offers an alternative way of bed-sharing.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry: ACTRN12610000993099.

Sleep and Skin Temperature in Preschool Children and Their Mothers

The purpose of this study was to investigate and compare sleep and skin temperature (Tsk) of preschool children with those of their mothers. The subjects included 18 pairs of preschool children and their mothers. The actigraphic measurement of sleep, Tsk, heart rate, bedroom climate, and the microclimate temperature and humidity (bed climate) were measured. Proximal and distal Tsk, the temperature gradient of distal and proximal Tsk (DPG), and bed climate temperature were significantly lower in the children. Approximately 70% of the children slept without bed covering. Heat dissipation during sleep in preschool children may primarily rely on the proximal Tsk. The lower Tsk than adults, and behavioral thermoregulation, may be important for sleep in preschoolers.

Adherence to Safe Sleep Recommendations by Families With Higher-order Multiples

BACKGROUND

More than 95% of higher-order multiples are born preterm and more than 90% are low birth weight, making this group of infants especially vulnerable to sudden infant death syndrome (SIDS). Emerging evidence suggests that families with twins face challenges adhering to the American Academy of Pediatrics (AAP) recommendations to reduce SIDS risks. Adherence to the AAP recommendations in families with higher-order multiples has not been described.

PURPOSE

This study describes SIDS risk reduction infant care practices for higher-order multiples during the first year of life.

METHODS

Mothers caring for higher-order multiple-birth infants were recruited from an online support group. An online survey was used to assess infant care practices when the infants were first brought home from the hospital as well as at the time of the survey.

RESULTS

Ten mothers of triplets and 4 mothers of quadruplets responded. Less than 80% of the mothers practiced "back to sleep" immediately postdischarge. Supine sleep positioning decreased over time, particularly during daytime naps. Only 50% of the infants shared the parents' bedroom and approximately 30% bed-shared with their siblings. Sleep-time pacifier use was low.

IMPLICATIONS FOR PRACTICE

Safe sleep education must include specific questions regarding home sleeping arrangements, encouragement of breast milk feedings, supine positioning, and pacifier use at every sleep for higher-order multiple infants well before discharge in order for parents to plan a safe sleep environment at home.

IMPLICATIONS FOR RESEARCH

Prospective studies to identify barriers and facilitators can inform future strategies supporting adherence to safe sleep practices for higher-order multiple infants.

Pituitary adenylate cyclase-activating polypeptide drives cardiorespiratory responses to heat stress in neonatal mice

The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) has emerged as a principal and rate-limiting regulator of physiological stress responses in adult rodents and has been implicated in sudden infant death syndrome (SIDS). Recent studies show that PACAP plays a role in neonatal cardiorespiratory responses to hypoxia, hypercapnia, and hypothermia, but not hyperthermia, which is often associated with SIDS. Here we tested the hypothesis that, consistent with a role in SIDS, PACAP is involved in regulating the neonatal cardiorespiratory responses to severe heat. To address this, we used head-out plethysmography and surface ECG electrodes to study the cardiorespiratory physiology of conscious neonatal PACAP-null and wild-type mice at ambient temperatures of 32°C (baseline) and 40°C (heat stress). We also assessed body surface temperature as an indicator of cutaneous heat loss. Our results show that wild-type neonatal mice respond to heat stress by increasing ventilation ( P = 0.007) and associated expired CO2 ( P = 0.041), heart rate ( P < 0.001), and cutaneous heat loss ( P < 0.001). In PACAP-null neonates, this heat response is impaired, as indicated by a decrease in ventilation ( P = 0.04) and associated expired CO2 ( P = 0.006) and a blunted increase in heart rate ( P = 0.001) and cutaneous heat loss ( P = 0.0002). In addition, heart rate variability at baseline was lower in PACAP-null neonates than wild-type controls ( P < 0.01). These results suggest that, during heat stress, PACAP is important for neonatal cardiorespiratory responses that help regulate body temperature. Abnormal PACAP regulation could, therefore, contribute to neonatal disorders in which the autonomic response to stress is impaired, such as SIDS.

Interactive effects of maternal cigarette smoke, heat stress, hypoxia, and lipopolysaccharide on neonatal cardiorespiratory and cytokine responses

Maternal cigarette smoke (CS) exposure exhibits a strong epidemiological association with Sudden Infant Death Syndrome, but other environmental stressors, including infection, hyperthermia, and hypoxia, have also been postulated as important risk factors. This study examines whether maternal CS exposure causes maladaptations within homeostatic control networks by influencing the response to lipopolysaccharide, heat stress, and/or hypoxia in neonatal rats. Pregnant dams were exposed to CS or parallel sham treatments daily for the length of gestation. Offspring were studied at postnatal days 6-8 at ambient temperatures (T_a) of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 µg/kg) treatments. Cardiorespiratory patterns were examined using head-out plethysmography and ECG surface electrodes during normoxia and hypoxia (10% O₂). Serum cytokine concentrations were quantified from samples taken at the end of each experiment. Our results suggest maternal CS exposure does not alter minute ventilation (V̇e) or heart rate (HR) response to infection or high temperature, but independently increases apnea frequency. CS also primes the inflammatory system to elicit a stronger cytokine response to bacterial insult. High T_a independently depresses V̇e but augments the hypoxia-induced increase in V̇e Moreover, higher T_a increases HR during normoxia and hypoxia, and in the presence of an immune challenge, increases HR during normoxia, and reduces the increase normally associated with hypoxia. Thus, while most environmental risk factors increase the burden on the cardiorespiratory system in early life, hyperthermia and infection blunt the normal HR response to hypoxia, and gestational CS independently destabilizes breathing by increasing apneas.

Cardiorespiratory control and cytokine profile in response to heat stress, hypoxia, and lipopolysaccharide (LPS) exposure during early neonatal period

Sudden infant death syndrome (SIDS) is one of the most common causes of postneonatal infant mortality in the developed world. An insufficient cardiorespiratory response to multiple environmental stressors (such as prone sleeping positioning, overwrapping, and infection), during a critical period of development in a vulnerable infant, may result in SIDS. However, the effect of multiple risk factors on cardiorespiratory responses has rarely been tested experimentally. Therefore, this study aimed to quantify the independent and possible interactive effects of infection, hyperthermia, and hypoxia on cardiorespiratory control in rats during the neonatal period. We hypothesized that lipopolysaccharide (LPS) administration will negatively impact cardiorespiratory responses to increased ambient temperature and hypoxia in neonatal rats. Sprague-Dawley neonatal rat pups were studied at postnatal day 6-8. Rats were examined at an ambient temperature of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 μg/kg) treatments. Cardiorespiratory and thermal responses were recorded and analyzed before, during, and after a hypoxic exposure (10% O2). Serum samples were taken at the end of each experiment to measure cytokine concentrations. LPS significantly increased cytokine concentrations (such as TNFα, IL-1β, MCP-1, and IL-10) compared to control. Our results do not support a three-way interaction between experimental factors on cardiorespiratory control. However, independently, heat stress decreased minute ventilation during normoxia and increased the hypoxic ventilatory response. Furthermore, LPS decreased hypoxia-induced tachycardia. Herein, we provide an extensive serum cytokine profile under various experimental conditions and new evidence that neonatal cardiorespiratory responses are adversely affected by dual interactions of environmental stress factors.

Parent-child bed-sharing: The good, the bad, and the burden of evidence

The practice of parent and child sharing a sleeping surface, or 'bed-sharing', is one of the most controversial topics in parenting research. The lay literature has popularized and polarized this debate, offering on one hand claims of dangers, and on the other, of benefits - both physical and psychological - associated with bed-sharing. To address the scientific evidence behind such claims, we systematically reviewed 659 published papers (peer-reviewed, editorial pieces, and commentaries) on the topic of parent-child bed-sharing. Our review offers a narrative walkthrough of the many subdomains of bed-sharing research, including its many correlates (e.g., socioeconomic and cultural factors) and purported risks or outcomes (e.g., sudden infant death syndrome, sleep problems). We found general design limitations and a lack of convincing evidence in the literature, which preclude making strong generalizations. A heat-map based on 98 eligible studies aids the reader to visualize world-wide prevalence in bed-sharing and highlights the need for further research in societies where bed-sharing is the norm. We urge for multiple subfields - anthropology, psychology/psychiatry, and pediatrics - to come together with the aim of understanding infant sleep and how nightly proximity to the parents influences children's social, emotional, and physical development.

Thermoregulatory effects of swaddling in Mongolia: a randomised controlled study

OBJECTIVE

To investigate thermal balance of infants in a Mongolian winter, and compare the effects of traditional swaddling with an infant sleeping-bag in apartments or traditional tents (Gers).

DESIGN

A substudy within a randomised controlled trial.

SETTING

Community in Ulaanbaatar, Mongolia.

SUBJECTS

A stratified randomly selected sample of 40 swaddled and 40 non-swaddled infants recruited within 48 h of birth.

INTERVENTION

Sleeping-bags and baby outfits of total thermal resistance equivalent to that of swaddled babies.

OUTCOME MEASURE

Digital recordings of infants' core, peripheral, environmental and microenvironmental temperatures at 30-s intervals over 24 h at ages 1 month and 3 months.

RESULTS

In Gers, indoor temperatures varied greatly (<0->25°C), but remained between 20°C and 22°C, in apartments. Despite this, heavy wrapping, bed sharing and partial head covering, infant core and peripheral temperatures were similar and no infants showed evidence of significant heat or cold stress whether they were swaddled or in sleeping-bags. At 3 months, infants in sleeping-bags showed the 'mature' diurnal pattern of a fall in core temperature after sleep onset, accompanied by a rise in peripheral temperature, with a reverse pattern later in the night, just before awakening. This pattern was not related to room temperature, and was absent in the swaddled infants, suggesting that the mature diurnal pattern may develop later in them.

CONCLUSIONS

No evidence of cold stress was found. Swaddling had no identifiable thermal advantages over sleeping-bags during the coldest times, and in centrally heated apartments could contribute to the risk of overheating during the daytime.

TRIAL REGISTRATION NUMBER

ISRTN01992617.

Ambient Heat and Sudden Infant Death: A Case-Crossover Study Spanning 30 Years in Montreal, Canada

BACKGROUND

Climate change may lead to more severe and extreme heat waves in the future, but its potential impact on sudden infant death-a leading cause of infant mortality-is unclear.

OBJECTIVES

We sought to determine whether risk of sudden infant death syndrome (SIDS) is elevated during hot weather.

METHODS

We undertook a case-crossover analysis of all sudden infant deaths during warm periods in metropolitan Montreal, Quebec, Canada, from 1981 through 2010. Our analysis included a total of 196 certified cases of SIDS, including 89 deaths at 1-2 months of age, and 94 at 3-12 months. We estimated associations between maximum outdoor temperatures and SIDS by comparing outdoor temperatures on the day of or day before a SIDS event with temperatures on control days during the same month, using cubic splines to model temperature and adjusting for relative humidity.

RESULTS

Maximum daily temperatures of ≥ 29°C on the same day were associated with 2.78 times greater odds of sudden infant death relative to 20°C (95% CI: 1.64, 4.70). The likelihood of sudden death increased steadily with higher temperature. Associations were stronger for infants 3-12 months of age than for infants 1-2 months of age, with odds ratios of 3.90 (95% CI: 1.87, 8.13) and 1.73 (95% CI: 0.80, 3.73), respectively, for 29°C compared with 20°C on the day of the event.

CONCLUSIONS

High ambient temperature may be a novel risk factor for SIDS, especially at ≥ 3 months of age. Climate change and the higher temperatures that result may account for a potentially greater proportion of sudden infant deaths in the future.

"Diagnosis by behavioral observation" home-videosomnography - a rigorous ethnographic approach to sleep of children with neurodevelopmental conditions

INTRODUCTION

Advanced video technology is available for sleep-laboratories. However, low-cost equipment for screening in the home setting has not been identified and tested, nor has a methodology for analysis of video recordings been suggested.

METHODS

We investigated different combinations of hardware/software for home-videosomnography (HVS) and established a process for qualitative and quantitative analysis of HVS-recordings. A case vignette (HVS analysis for a 5.5-year-old girl with major insomnia and several co-morbidities) demonstrates how methodological considerations were addressed and how HVS added value to clinical assessment.

RESULTS

We suggest an "ideal set of hardware/software" that is reliable, affordable (∼$500) and portable (=2.8 kg) to conduct non-invasive HVS, which allows time-lapse analyses. The equipment consists of a net-book, a camera with infrared optics, and a video capture device. (1) We present an HVS-analysis protocol consisting of three steps of analysis at varying replay speeds: (a) basic overview and classification at 16× normal speed; (b) second viewing and detailed descriptions at 4-8× normal speed, and (c) viewing, listening, and in-depth descriptions at real-time speed. (2) We also present a custom software program that facilitates video analysis and note-taking (Annotator(©)), and Optical Flow software that automatically quantifies movement for internal quality control of the HVS-recording. The case vignette demonstrates how the HVS-recordings revealed the dimension of insomnia caused by restless legs syndrome, and illustrated the cascade of symptoms, challenging behaviors, and resulting medications.

CONCLUSION

The strategy of using HVS, although requiring validation and reliability testing, opens the floor for a new "observational sleep medicine," which has been useful in describing discomfort-related behavioral movement patterns in patients with communication difficulties presenting with challenging/disruptive sleep/wake behaviors.

Sudden unexpected death in infancy: biological mechanisms

Sudden unexpected death in infancy (SUDI) covers both explained and unexplained deaths. Unexplained cases or SIDS are likely to have multiple neural mechanisms contributing to the final event. The evidence ranges from subtle physiological signs related to autonomic control, to findings at autopsy of altered neurotransmitter systems, including the serotonergic system, a network that has an extensive homeostatic role in cardio-respiratory and thermoregulatory control. Processes may be altered by the vulnerability of the infant due to age, poor motor ability, or a genetic predisposition. The fatal event may occur in response to an environmental stress. A single final physiological route to death seems unlikely. An understanding of the reasons for explained SUDI also reminds us that a thorough investigation is required after each death occurs.

Longitudinal study of sleep behavior in normal infants during the first year of life

STUDY OBJECTIVES

To longitudinally examine sleep patterns, habits, and parent-reported sleep problems during the first year of life.

METHODS

Seven hundred four parent/child pairs participated in a longitudinal cohort study. Structured interview recording general demographic data, feeding habits, intercurrent diseases, family history, sleep habits, and parental evaluation of the infant's sleep carried out at 1, 3, 6, 9, and 12 months.

RESULTS

Nocturnal, daytime, and total sleep duration showed a high inter-individual variability in the first year of life associated with changes in the first 6 months and stability from 6 to 12 months. Bedtime was at around 22:00 and remained stable at 6, 9, and 12 months of age. Approximately 20% of the infants had more than 2 awakenings and slept more often in the parent bed. Nearly 10% of the infants were considered as having a problematic sleep by parents and this significantly correlated with nocturnal awakenings and difficulties falling asleep.

CONCLUSIONS

Sleep patterns change during the first year of life but most sleep variables (i.e., sleep latency and duration) show little variation from 6 to 12 months. Our data provide a context for clinicians to discuss sleep issues with parents and suggest that prevention efforts should focus to the first 3-6 months, since sleep patterns show stability from that time point to 12 months.

Methodology and recruitment for a randomised controlled trial to evaluate the safety of wahakura for infant bedsharing

BACKGROUND

Sudden Unexpected Death in Infancy (SUDI) has persistent high rates in deprived indigenous communities and much of this mortality is attributable to unsafe sleep environments. Whilst health promotion worldwide has concentrated on avoidance of bedsharing, the indigenous Māori community in New Zealand has reproduced a traditional flax bassinet (wahakura) designed to be used in ways that include bedsharing. To date there has been no assessment of the safety of this traditional sleeping device.

METHODS/DESIGN

This two arm randomised controlled trial is being conducted with 200 mother-baby dyads recruited from Māori communities in areas of high deprivation in the Hawkes Bay, New Zealand. They are randomised to wahakura or bassinet use and investigation includes questionnaires at baseline (pregnancy), when baby is 1, 3, and 6 months, and an overnight video sleep study at 1 month with monitoring of baby temperature and oxygen saturation, and measurement of baby urinary cotinine and maternal salivary oxytocin. Outcome measures are amount of time head covered, amount of time in thermal comfort zone, number of hypoxic events, amount of time in the assigned sleep device, amount of time breastfeeding, number of parental (non-feed related) touching infant events, amount of time in the prone sleep position, the number of behavioural arousals and the amount of time infant is awake overnight. Survey data will compare breastfeeding patterns at 1, 3, and 6 months as well as data on maternal mind-mindedness, maternal wellbeing, attachment to baby, and maternal sleep patterns.

DISCUSSION

Indigenous communities require creative SUDI interventions that fit within their prevailing world view. This trial, and its assessment of the safety of a wahakura relative to a standard bassinet, is an important contribution to the range of SUDI prevention research being undertaken worldwide.

TRIALS REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12610000993099 Registered 16th November 2010.

Influence of gestational diabetes on circadian rhythms of children and their association with fetal adiposity

OBJECTIVE

To analyse the circadian rhythm maturation of temperature, activity and sleep during the first year of life in offspring of diabetic mothers (ODM) and its relationship with obesity markers.

METHODS

A prospective analysis of the children of 63 pregnant women (23 controls, 21 gestational diabetes mellitus (GDM) controlled with diet and 19 GDM with insulin). Fetal abdominal circumference was evaluated ecographically during gestation. Skin temperature and rest-activity rhythms were monitored for 3 consecutive days in children at 15 days and 1, 3 and 6 months. Anthropometrical parameters of the children were evaluated during the first year of life.

RESULTS

Children from the GDM groups tended to higher fetal abdominal circumference z-score than controls at the beginning of the last trimester (p = 0.077) and at delivery (p = 0.078). Mean skin temperature or activity was not different among the groups. The I < O sleep index pointed to increasing concordance with parental sleeping at 3 and 6 months but no significant GDM-dependent differences. However, some of the parameters that define temperature maturation and also the circadian function index from the temperature-activity variable were significantly lower at 6 months in the GDM + insulin group. Fetal abdominal circumference z-score, as a predictor of fetal adiposity, correlated negatively with parameters related to circadian rhythm maturation as the circadian/ultradian rhythm (P1 /Pult ratio).

CONCLUSIONS

Fetal adiposity correlated with a worse circadian rhythm regulation in ODM. In addition, ODM insulin-treated showed a disturbed pattern of the circadian function index of temperature activity at 6 months of age.

Hypoxic and hypercapnic events in young infants during bed-sharing

OBJECTIVES

To identify desaturation events (arterial oxygen saturation [Sao(2)] <90%) and rebreathing events (inspired carbon dioxide (CO(2)) >3%), in bed-sharing (BS) versus cot-sleeping (CS) infants.

METHODS

Forty healthy, term infants, aged 0 to 6 months who regularly bed-shared with at least 1 parent >5 hours per night and 40 age-matched CS infants were recruited. Overnight parent and infant behavior (via infrared video), Sao(2), inspired CO(2) around the infant's face, and body temperature were recorded during sleep at home.

RESULTS

Desaturation events were more common in BS infants (risk ratio = 2.17 [95% confidence interval: 1.75 to 2.69]), associated partly with the warmer microenvironment during BS. More than 70% of desaturations in both groups were preceded by central apnea of 5 to 10 seconds with no accompanying bradycardia, usually in active sleep. Apnea >15 seconds was rare (BS infants: 3 events; CS infants: 6 events), as was desaturation <80% (BS infants: 3 events; CS infants: 4 events). Eighty episodes of rebreathing were identified from 22 BS infants and 1 CS infant, almost all preceded by head covering. During rebreathing, Sao(2) was maintained at the baseline of 97.6%.

CONCLUSIONS

BS infants experienced more oxygen desaturations preceded by central apnea, partly related to the warmer microenvironment. Rebreathing occurred mainly during bed-sharing. Infants were at low risk of sudden infant death syndrome and maintained normal oxygenation. The effect of repeated exposure to oxygen desaturation in vulnerable infants is unknown as is the ability of vulnerable infants to respond effectively to rebreathing caused by head covering.

Bed sharing and the risk of sudden infant death syndrome: can we resolve the debate?

OBJECTIVE

To conduct a meta-analysis on the relationship between bed sharing and sudden infant death syndrome (SIDS) risk.

STUDY DESIGN

Data from PubMed and Medline were searched for studies published after Jan 1, 1970. The search strategy included articles with the terms "sudden infant death syndrome," "sudden unexpected death," and "cot death" with "bed sharing" or "co-sleeping." To further specify the potential risk of bed sharing and SIDS, subgroup analyses were performed.

RESULTS

Eleven studies met inclusion criteria and were included in the final meta-analysis. The combined OR for SIDS in all bed sharing versus non-bed sharing infants was 2.89 (95% CI, 1.99-4.18). The risk was highest for infants of smoking mothers (OR, 6.27; 95% CI, 3.94-9.99), and infants <12 weeks old (OR, 10.37; 95% CI, 4.44-24.21).

CONCLUSIONS

Bed sharing is a risk factor for SIDS and is especially enhanced in smoking parents and in very young infants.

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).

Decisions of black parents about infant bedding and sleep surfaces: a qualitative study

OBJECTIVE

The goal of this qualitative study was to examine factors influencing decisions by black parents regarding use of soft bedding and sleep surfaces for their infants.

METHODS

We conducted focus groups and individual interviews with black mothers of lower and higher socioeconomic status (SES). Mothers were asked about many infant care practices, including sleep surface and bedding.

RESULTS

Eighty-three mothers were interviewed, 73 (47 lower and 26 higher SES) in focus groups and 10 (7 lower and 3 higher SES) in individual interviews. The primary reason for using soft surfaces was infant comfort. Parents perceived that infants were uncomfortable if the surface was not soft. Many parents also interpreted "firm sleep surface" to mean taut; they were comfortable with and believed that they were following recommendations for a firm sleep surface when they placed pillows/blankets on the mattress as long as a sheet was pulled tautly over the pillows/blankets. The primary reasons for using soft bedding (including bumper pads) were comfort, safety, and aesthetics. In addition to using bedding to soften sleep surfaces, bedding was used to prevent infant rollover and falls, particularly for infants sleeping on a bed or sofa. Some parents used soft bedding to create an attractive space for the infant.

CONCLUSIONS

Many black parents believe that soft bedding will keep their infant safe and comfortable. There is much misunderstanding about the meaning of a "firm" sleep surface. Additional educational messages apparently are needed to change parental perceptions and practices.

Assessment of circadian rhythms of both skin temperature and motor activity in infants during the first 6 months of life

The authors developed a method useful for home measurement of temperature, activity, and sleep rhythms in infants under normal-living conditions during their first 6 mos of life. In addition, parametric and nonparametric tests for assessing circadian system maturation in these infants were compared. Anthropometric parameters plus ankle skin temperature and activity were evaluated in 10 infants by means of two data loggers, Termochron iButton (DS1291H, Maxim Integrated Products, Sunnyvale, CA) for temperature and HOBO Pendant G (Hobo Pendant G Acceleration, UA-004-64, Onset Computer Corporation, Bourne, MA) for motor activity, located in special baby socks specifically designed for the study. Skin temperature and motor activity were recorded over 3 consecutive days at 15 days, 1, 3, and 6 mos of age. Circadian rhythms of skin temperature and motor activity appeared at 3 mos in most babies. Mean skin temperature decreased significantly by 3 mos of life relative to previous measurements (p = .0001), whereas mean activity continued to increase during the first 6 mos. For most of the parameters analyzed, statistically significant changes occurred at 3-6 mos relative to 0.5-1 mo of age. Major differences were found using nonparametric tests. Intradaily variability in motor activity decreased significantly at 6 mos of age relative to previous measurements, and followed a similar trend for temperature; interdaily stability increased significantly at 6 mos of age relative to previous measurements for both variables; relative amplitude increased significantly at 6 mos for temperature and at 3 mos for activity, both with respect to previous measurements. A high degree of correlation was found between chronobiological parametric and nonparametric tests for mean and mesor and also for relative amplitude versus the cosinor-derived amplitude. However, the correlation between parametric and nonparametric equivalent indices (acrophase and midpoint of M5, interdaily stability and Rayleigh test, or intradaily variability and P(1)/P(ultradian)) despite being significant, was lower for both temperature and activity. The circadian function index (CFI index), based on the integrated variable temperature-activity, increased gradually with age and was statistically significant at 6 mos of age. At 6 mos, 90% of the infants' rest period coincided with the standard sleep period of their parents, defined from 23:00 to 07:00 h (dichotomic index I < O; when I < O = 100%, there is a complete coincidence between infant nocturnal rest period and the standard rest period), whereas at 15 days of life the coincidence was only 75%. The combination of thermometry and actimetry using data loggers placed in infants' socks is a reliable method for assessing both variables and also sleep rhythms in infants under ambulatory conditions, with minimal disturbance. Using this methodological approach, circadian rhythms of skin temperature and motor activity appeared by 3 mos in most babies. Nonparametric tests provided more reliable information than cosinor analysis for circadian rhythm assessment in infants.

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.

Bed sharing among black infants and sudden infant death syndrome: interactions with other known risk factors

OBJECTIVE

Bed sharing has been associated with sudden infant death syndrome (SIDS) and may contribute to the racial disparity seen in infant mortality. It is unclear how bed sharing interacts with other factors to impact SIDS risk. We aimed to measure the effects of bed sharing on risk of SIDS in blacks and to determine whether the risk is modified by other characteristics of the sleep environment.

METHODS

Characteristics of 195 black infants who died of SIDS were compared with matched controls. The moderating influence of known SIDS risk factors on the effect of bed sharing on risk of SIDS was examined using logistic regression.

RESULTS

Almost half (47.4%) of the study population bed shared during the last/reference sleep (58% cases and 37% controls). Bed sharing was associated with 2 times greater risk of SIDS compared with not bed sharing. The deleterious effect of bed sharing was more pronounced with a soft sleep surface, pillow use, maternal smoking, and younger infant age. However, bed sharing was still associated with an increased risk of SIDS, even when the infant was not using a pillow or sleeping on a firm surface. The strongest predictors of SIDS among bed-sharing infants were soft sleep surface, nonuse of a pacifier, and maternal smoking during pregnancy.

CONCLUSIONS

Bed sharing is a common practice among black infants. It is associated with a clear and strong increased risk of SIDS, which is even greater when combined with other known risk factors for SIDS. This practice likely contributes to the excess incidence of SIDS among blacks, and culturally competent education methods must be developed to target this high-risk group.

Evaluation of the thermal insulation of clothing of infants sleeping outdoors in Northern winter

It is a common practice in Northern countries that children aged about 2 weeks to 2 years take their daytime sleep outdoors in prams in winter. The aim was to evaluate the thermal insulation of clothing of infants sleeping outdoors in winter. Clothing data of infants aged 3.5 months was collected, and sleep duration, skin and microclimate temperatures, humidity inside middle wear, air temperature and velocity of the outdoor environment were recorded during sleep taken outdoors (n = 34) and indoors (n = 33) in families' homes. The insulation of clothing ensembles was measured by using a baby-size thermal manikin, and the values were used for defining clothing insulation of the observed infants. Required clothing insulation for each condition was estimated according to ISO 11079. Clothing insulation did not correlate with ambient air temperature. The observed and required insulation of the study group was equal at about -5 °C, but overdressing existed in warmer and deficiency in thermal insulation in colder temperatures (r (s) 0.739, p < 0.001). However, even at -5 °C a slow cooling (ca. 0.012 °C/min) of mean skin temperature (T (sk)) was observed. When the difference between observed and required insulation increased, the cooling rate of T (sk) increased linearly (r (s) 0.605, p < 0.001) and the infants slept for a shorter period (r (s) 0.524, p = 0.001). The results of this study show the difficulty of adjusting systematically the optimal thermal insulation for outdoor sleeping infants during northern winter. Therefore, the necessity for guidelines is obvious. The study provides information for adequate cold protection of infants sleeping in cold conditions.

Infants sleeping outdoors in a northern winter climate: skin temperature and duration of sleep

AIM

The aim of the study is to describe the relationships among thermal environment, skin temperatures and infants' daytime outdoor sleep duration in northern winter conditions.

METHODS

This study is a cross-over observational study. Skin temperatures of three-month-old infants were recorded from seven skin sites continuously throughout outdoor (n = 34) and indoor sleep (n = 33) in the families' homes. The duration of the sleep was observed, and temperature and the air velocity of the environment were recorded.

RESULTS

Skin temperatures increased towards the end of indoor sleeping, whereas they decreased during outdoor sleeping. The cooling rate of mean skin temperature (T(sk)) increased in lower outdoor temperatures (r(s) = .628, p < 0.001) in spite of increased clothing. On some occasions, cold extremities were observed, suggesting slight deviations from thermoneutrality. Sleep time was 92 min longer in outdoors than in indoors. However, outdoor sleep duration was shortened when the cooling rate of T(sk) increased (r(s) = 0.611, p < 0.001).

CONCLUSION

The longest sleep was recorded outdoors when the cooling rate of T(sk) was minimal. Restriction of movements by clothing probably increases the length of sleep, and a cold environment makes swaddling possible without overheating. A decrease in ambient temperature increased the cooling rate, suggesting that the cold protection of the clothing compensated only partly for the increased heat loss.

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.

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.

Bed- and room-sharing in Chinese school-aged children: prevalence and association with sleep behaviors

OBJECTIVE

To survey the prevalence of bed- and room-sharing and assess associations with sleep/wake patterns, duration of sleep, and sleep problems among urban school-aged children in China.

METHODS

Students representing eight Chinese cities were studied during November and December, 2005. A total of 19,299 elementary-school children (49.7% boys and 50.3% girls with a mean age of 9.00 years) participated in the survey. A parent-administered questionnaire and the Chinese version of the Children's Sleep Habits Questionnaire were completed to quantify children's sleep arrangements and to characterize sleep behaviors.

RESULTS

Co-sleeping was a common practice, with a prevalence of 37.6% (routine bed-sharing: 23.0%; room-sharing: 14.6%) in Chinese school-aged children. Bed- and room-sharing did not show significant gender difference but gradually decreased with increasing age. Compared to room-sharing and sleeping alone, bed-sharing was correlated with later bedtimes, later awakening times, and a shorter duration of sleep. However, the small difference was unlikely to have clinical significance. Bed- and room-sharing tended to be associated with the increased probability of six types of sleep problems: bedtime resistance, sleep anxiety, night waking, parasomnia, sleep-disordered breathing, and daytime sleepiness. Compared to bed-sharing, room-sharing had a lower odds ratio. Among six sleep problems, bedtime resistance and sleep anxiety had the strongest association with bed-sharing.

CONCLUSIONS

Sleep problems were common in Chinese school-aged children. Co-sleeping was highly prevalent and may be potentially associated with negative effects on sleep hygiene and sleep quality, although the context of the co-sleeping must be taken into consideration.

Sleep arrangements and behavior of bed-sharing families in the home setting

OBJECTIVES

We aimed to provide a quantitative analysis of the sleep arrangements and behaviors of bed-sharing families to further understand the risks and benefits as well as the effects of infant age and room temperature on bed-sharing behaviors.

METHODS

Forty infants who regularly bed shared with > or = 1 parent > or = 5 hours per night were recruited. Overnight video of the family and physiological monitoring of the infant was conducted in infants' homes. Infant sleep position, potential for exposure to expired air, head covering and uncovering, breastfeeding, movements, family sleep arrangements, responses to the infant, and interactions were logged.

RESULTS

All infants slept with their mother. Fathers were included in 18 studies and siblings in 4. Infants usually slept beside the mother, separated from the father/siblings (if present), facing the mother, with head at mothers' breast level, touching, or with mother cradling. Median overnight breastfeeding duration was 40.5 minutes. Mothers commonly faced their infant, but infants were rarely in a position that potentially exposed them to maternal expired air. Fathers were seldom in contact with the infant during sleep. Of the 102 head-covering episodes observed in 22 infants, 80% were because of changes in adult sleep position. Sixty-eight percent of head uncovering was facilitated by the mother; half of these events were prompted by the infant. A 1 degree C increase in room temperature decreased infant head covering by 0.2 hours.

CONCLUSIONS

The mother-infant relationship is of prime importance during bed sharing, whether the father is present or not. The focus around breastfeeding often dictates the sleep position of the infant and mother, though room temperature may also influence this. In colder rooms infants tend to spend more time with their face covered by bedding. Frequent maternal interactions rely on the ability of the mother to arouse with little stimulation. Mothers, perhaps impaired by alcohol, smoking, or overtiredness, may not be able to respond appropriately.

Parent-infant co-sleeping and its relationship to breastfeeding

Co-sleeping can provide numerous benefits for both the parent(s) and the infant. Perhaps the greatest advantage lies in its promotion of breastfeeding, an act widely recognized for its benefits to both the mother and infant. However, risks also are associated with co-sleeping, prompting many researchers to examine the safety of its practice. Pediatric nurse practitioners need to be informed on issues related to co-sleeping in order to educate parents regarding its risks and benefits, to assess the safety of an established sleeping environment, and to be aware of its prevalence in their patient populations. A review of the literature is presented to inform pediatric nurse practitioners about varied definitions of co-sleeping, the reasons why some parents engage in the practice, cultural preferences for co-sleeping, associated risks and benefits, and its relationship to breastfeeding.

Differences in infant and parent behaviors during routine bed sharing compared with cot sleeping in the home setting

OBJECTIVES

To observe the behavior of infants sleeping in the natural physical environment of home, comparing the 2 different sleep practices of bed sharing and cot sleeping quantifying to factors that have been identified as potential risks or benefits.

METHODS

Forty routine bed-sharing infants, aged 5-27 weeks were matched for age and season of study with 40 routine cot-sleeping infants. Overnight video and physiologic data of bed-share infants and cot-sleep infants were recorded in the infants' own homes. Sleep time, sleep position, movements, feeding, blanket height, parental checks, and time out of the bed or cot were logged.

RESULTS

The total sleep time was similar in both groups (bed-sharing median: 8.6 hours; cot-sleeping median: 8.2 hours). Bed-sharing infants spent most time in the side position (median: 5.7 hours, 66% of sleep time) and most commonly woke at the end of sleep in this position, whereas cot-sleeping infants most commonly slept supine (median: 7.5 hours, 100%) and woke at the end of sleep in the supine position. Prone sleep was uncommon in both groups. Head covering above the eyes occurred in 22 bed-sharing infants and 1 cot-sleeping infant. Five of these bed-sharing infants were head covered at final waking time, but the cot-sleeping infant was not. Bed-sharing parents looked at or touched their infant more often (median: 11 vs 4 times per night) but did not always fully wake to do so. Movement episodes were shorter in the bed-sharing group as was total movement time (37 vs 50 minutes respectively), whereas feeding was 3.7 times more frequent in the bed-sharing group than the cot-sleeping group.

CONCLUSIONS

Bed-share infants without known risk factors for sudden infant death syndrome (SIDS) experience increased maternal touching and looking, increased breastfeeding, and faster and more frequent maternal responses. This high level of interaction is unlikely to occur if maternal arousal is impaired, for example, by alcohol or overtiredness. Increased head covering and side sleep position occur during bed-sharing, but whether these factors increase the risk of SIDS, as they do in cot sleeping, requires further investigation.

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.