A review of the effects of sleep during the first year of life on cognitive, psychomotor, and temperament development

Eight principles for patient-centred and family-centred care for newborns in the neonatal intensive care unit

Despite the recent improvements in perinatal medical care leading to an increase in survival rates, adverse neurodevelopmental outcomes occur more frequently in preterm and/or high-risk infants. Medical risk factors for neurodevelopmental delays like male gender or intrauterine growth restriction and family sociocultural characteristics have been identified. Significant data have provided evidence of the detrimental impact of overhelming environmental sensory inputs, such as pain and stress, on the developing human brain and strategies aimed at preventing this impact. These strategies, such as free parental access or sleep protection, could be considered 'principles of care'. Implementation of these principles do not require additional research due to the body of evidence. We review the scientific evidence for these principles here.

Naps improve new walkers' locomotor problem solving

In this first study of the impact of sleep on infants' problem solving of a locomotor task, 28 newly walking infants who were within a week of having given up crawling trained to navigate a shoulder-height tunnel to reach a caregiver waiting at the end. During the transitional window between crawling and walking, infants are reluctant to return to crawling, making this task uniquely challenging. Infants were randomly assigned to either nap or stay awake during a delay between training and a later test session. For the Nap group, efficiency of problem solving improved from training to test, but there was no change for the No Nap group. These findings suggest that for newly walking infants, sleep facilitates learning to solve a novel motor problem.

Vibrotactile stimulation: A non-pharmacological intervention for opioid-exposed newborns

Objective

To examine the therapeutic potential of stochastic vibrotactile stimulation (SVS) as a complementary non-pharmacological intervention for withdrawal in opioid-exposed newborns.

Study design

A prospective, within-subjects single-center study was conducted in 26 opioid-exposed newborns (>37 weeks; 16 male) hospitalized since birth and treated pharmacologically for Neonatal Abstinence Syndrome. A specially-constructed mattress delivered low-level SVS (30-60Hz, 10–12μm RMS), alternated in 30-min intervals between continuous vibration (ON) and no vibration (OFF) over a 6–8 hr session. Movement activity, heart rate, respiratory rate, axillary temperature and blood-oxygen saturation were calculated separately for ON and OFF.

Results

There was a 35% reduction in movement activity with SVS (p<0.001), with significantly fewer movement periods >30 sec duration for ON than OFF (p = 0.003). Incidents of tachypneic breaths and tachycardic heart beats were each significantly reduced with SVS, whereas incidents of eupneic breaths and eucardic heart beats each significantly increased with SVS (p<0.03). Infants maintained body temperature and arterial-blood oxygen level independent of stimulation condition.

Conclusions

SVS reduced hyperirritability and pathophysiological instabilities commonly observed in pharmacologically-managed opioid-exposed newborns. SVS may provide an effective complementary therapeutic intervention for improving autonomic function in newborns with Neonatal Abstinence Syndrome.

Daily touchscreen use in infants and toddlers is associated with reduced sleep and delayed sleep onset

Traditional screen time (e.g. TV and videogaming) has been linked to sleep problems and poorer developmental outcomes in children. With the advent of portable touchscreen devices, this association may be extending down in age to disrupt the sleep of infants and toddlers, an age when sleep is essential for cognitive development. However, this association has not been demonstrated empirically. This study aims to examine whether frequency of touchscreen use is associated with sleep in infants and toddlers between 6 and 36 months of age. An online survey was administered to 715 parents reporting on child media use (daily exposure to TV and use of touchscreens), sleep patterns (night-time and daytime sleep duration, sleep onset - time to fall asleep, and frequencies of night awakenings). Structural equation models controlling for age, sex, TV exposure and maternal education indicated a significant association between touchscreen use and night-time sleep, daytime sleep and sleep onset. No significant effect was observed for the number of night awakenings. To our knowledge, this is the first report linking the use of touchscreen with sleep problems in infants and toddlers. Future longitudinal studies are needed to clarify the direction of effects and the mechanisms underlying these associations using detailed sleep tracking.

Sleep patterns of young children with newly diagnosed atopic dermatitis

Introduction

Even though atopic dermatitis (AD) most often begins in the first year of life, it is not well known whether sleep disturbances occur following the onset of the disease or whether they develop later.

Aim

To determine the sleep patterns of young children already diagnosed with AD in comparison to a control group by using a validated questionnaire, the Brief Infant Sleep Questionnaire (BISQ).

Material and methods

Forty-six children with a new diagnosis of AD and 60 healthy children, aged 3–36 months, participated in the study. Their sleep behaviors were assessed using the BISQ along with a structured sociodemographic data form.

Results

It was found that when compared with healthy children, children with AD did not have decreased daily total sleep duration (p = 0.1); however, it was found that they woke up more frequently at night (52.2% vs. 40%, p = 0.4) and they stayed awake significantly longer than 60 min when they woke up (41.3% vs. 11.7%, p < 0.05). In addition, mothers of children with AD reported that their children had three times as many sleep problems compared to the reports of mothers of healthy children.

Conclusions

The findings of this study showed that sleep disturbance was more common in young children with already diagnosed AD, and the BISQ provided a practical way to assess the sleep patterns. The use of a screening tool to enable early identification and treatment of childhood sleep problems among patients with AD should be encouraged.

Sleep confers a benefit for retention of statistical language learning in 6.5month old infants

Infants show robust ability to track transitional probabilities within language and can use this information to extract words from continuous speech. The degree to which infants remember these words across a delay is unknown. Given well-established benefits of sleep on long-term memory retention in adults, we examine whether sleep similarly facilitates memory in 6.5month olds. Infants listened to an artificial language for 7minutes, followed by a period of sleep or wakefulness. After a time-matched delay for sleep and wakefulness dyads, we measured retention using the head-turn-preference procedure. Infants who slept retained memory for the extracted words that was prone to interference during the test. Infants who remained awake showed no retention. Within the nap group, retention correlated with three electrophysiological measures (1) absolute theta across the brain, (2) absolute alpha across the brain, and (3) greater fronto-central slow wave activity (SWA).

Sleep problems and temperament in young children with Down syndrome and typically developing controls

BACKGROUND

Although group differences have been found between children with Down syndrome (DS) and typically developing (TD) children when considering sleep problems and temperament independently, none of the research conducted to date has examined sleep-temperament associations in children with DS. The present research was conducted to determine (1) whether the sleep problems experienced by children with DS are associated with temperament or (2) if the demonstrated relations between sleep and temperament differ from those that are observed in TD children.

METHOD

The present study included examination of relations between parent-reported sleep problems and temperament in 19 children with DS and 20 TD controls matched on developmental age.

RESULTS

The results revealed group differences in temperament and sleep problems. Mediation models indicated that temperament (effortful control and inhibitory control) mediated the association between group and sleep problems; sleep problems also mediated the association between group and temperament (effortful and inhibitory control).

CONCLUSION

Findings indicated that sleep problems may serve as both cause and consequence of variability in effortful and inhibitory control and provide insight as to future experimental studies that should be conducted to better elucidate these relations.

Effects of Handling and Environment on Preterm Newborns Sleeping in Incubators

OBJECTIVE

To describe the total sleep time, stages of sleep, and wakefulness of preterm newborns and correlate them to levels of sound pressure, light, temperature, relative air humidity, and handling inside incubators.

DESIGN

Observational, correlational study.

SETTING

A neonatal intermediate care unit.

PARTICIPANTS

Twelve preterm newborns, who were 32.2 ± 4.2 weeks gestational age and weighed 1,606 ± 317 g.

METHODS

Sleep records were assessed by polysomnograph. Environmental variables were measured with a noise dosimeter, light meter, and thermohygrometer. To record time and frequency of handling, a video camera was used. All recordings were made for an uninterrupted 24-hour period.

RESULTS

Mean total sleep time in 24 hours was 899 ± 71.8 minutes (daytime = 446 ± 45.3 and nighttime = 448 ± 60.2). Mean wakefulness was 552 ± 94.0 minutes. The predominant stage was quiet sleep. A significant correlation was identified only between the levels of light and wakefulness (r = 0.65 and p = .041).

CONCLUSION

The environmental conditions and care provided to hospitalized preterm newborns did not influence sleep except for high light levels, which increased wakefulness. Nurses in clinical practice should implement strategies to promote and protect sleep by decreasing newborns' exposure to excessive light.

A Developmental Cascade Model of Behavioral Sleep Problems and Emotional and Attentional Self-Regulation Across Early Childhood

This article documents the longitudinal and reciprocal relations among behavioral sleep problems and emotional and attentional self-regulation in a population sample of 4,109 children participating in Growing Up in Australia: The Longitudinal Study of Australian Children (LSAC)-Infant Cohort. Maternal reports of children's sleep problems and self-regulation were collected at five time-points from infancy to 8-9 years of age. Longitudinal structural equation modeling supported a developmental cascade model in which sleep problems have a persistent negative effect on emotional regulation, which in turn contributes to ongoing sleep problems and poorer attentional regulation in children over time. Findings suggest that sleep behaviors are a key target for interventions that aim to improve children's self-regulatory capacities.

Maternal depressed mood moderates the impact of infant sleep on mother-infant bonding

Parent-infant bonding has long-term consequences for the psychological wellbeing of the child. Considering the centrality of infant sleep patterns in infant-caregiver interactions in the first year of life, we propose that infant sleep patterns act as a catalyst or disruptor for mother-infant relationship, such that infant sleep patterns contribute to maternal mood, maternal sleep quality, perception of infant temperament, and her bonding experience. One hundred fifty-two Israeli mothers, of 5-8-month-old infants, responded to Internet-based questionnaires regarding their sleep, their mood, their infant's sleep, the infant's temperament, and their bonding experience. Eight percent of the mothers reported clinically significant depression, while 67 % reported significant sleep difficulties. Infant sleep difficulties correlated with maternal mood and sleep quality, infant fussiness, and bonding. Structural equation modeling demonstrated that maternal sleep partially mediated the relationship between infant sleep and maternal mood. Additionally, 22 % of the variance in bonding was explained by infant sleep problems and temperament. Notably, maternal depression moderated this effect such that infant sleep problems correlated with bonding only in those mothers who were depressed. The results suggest that infant sleep is a vector by which maternal cognitions and mood are transmitted to her child, with long-term implications for psychological development.

Frequent daytime naps predict vocabulary growth in early childhood

BACKGROUND

The facilitating role of sleep for language learning is well-attested in adults and to a lesser extent in infants and toddlers. However, the longitudinal relationship between sleep patterns and early vocabulary development is not well understood.

METHODS

This study investigates how measures of sleep are related to the development of vocabulary size in infants and toddlers. Day and night-time sleeping patterns of infants and toddlers were compared with their concurrent and subsequent vocabulary development. Sleep assessments were conducted using a sleep diary specifically designed to facilitate accurate parental report. Sleep measures were used as predictors in a multilevel growth curve analysis of vocabulary development.

RESULTS

The number of daytime naps was positively associated with both predicted expressive (p = .062) and receptive vocabulary growth (p = .006), whereas the length of night-time sleep was negatively associated with rate of predicted expressive vocabulary growth (p = .045). Sleep efficiency was also positively associated with both predicted receptive (p = .001) and expressive vocabulary growth (p = .068).

CONCLUSIONS

These results point to a longitudinal relationship between sleep and language development, with a particular emphasis on the importance of napping at this age.

Unraveling the Neurobiology of Sleep and Sleep Disorders Using Drosophila

Sleep disorders in humans are increasingly appreciated to be not only widespread but also detrimental to multiple facets of physical and mental health. Recent work has begun to shed light on the mechanistic basis of sleep disorders like insomnia, restless legs syndrome, narcolepsy, and a host of others, but a more detailed genetic and molecular understanding of how sleep goes awry is lacking. Over the past 15 years, studies in Drosophila have yielded new insights into basic questions regarding sleep function and regulation. More recently, powerful genetic approaches in the fly have been applied toward studying primary human sleep disorders and other disease states associated with dysregulated sleep. In this review, we discuss the contribution of Drosophila to the landscape of sleep biology, examining not only fundamental advances in sleep neurobiology but also how flies have begun to inform pathological sleep states in humans.

PARENTAL REGULATION OF INFANT SLEEP: ROUND-THE-CLOCK EFFORTS FOR SOCIAL SYNCHRONIZATION

The sleep-cycle development of infants is influenced by familial and sociocultural conditions, but there is a lack of knowledge on how parental regulation of infant sleep is related to the specific life situation of a family. This article describes a context-sensitive study of parental regulation of infant sleep that includes the whole 24-hr day, parents' intentions, and familial and sociocultural conditions. The results are based on a longitudinal qualitative study in Norway of 51 families. Parents were interviewed in the infants' first year of life and approximately 18 months later. An interpretive analysis in four steps was conducted, informed by cultural psychological perspectives on development. The parents were found to perform five types of regulatory actions: facilitating sleep, letting sleep, letting be awake, keeping awake, and waking. These actions were performed continuously throughout the 24-hr day, each to different extents and at different hours in individual families, forming a regulation cycle. We describe patterns and variations in regulation cycles, changes over time as increased social synchronization, and how the regulation cycle is embedded in familial and sociocultural conditions. Finally, implications for clinical practice are discussed.

The extended trajectory of hippocampal development: Implications for early memory development and disorder

Hippocampus has an extended developmental trajectory, with refinements occurring in the trisynaptic circuit until adolescence. While structural change should suggest a protracted course in behavior, some studies find evidence of precocious hippocampal development in the first postnatal year and continuity in memory processes beyond. However, a number of memory functions, including binding and relational inference, can be cortically supported. Evidence from the animal literature suggests that tasks often associated with hippocampus (visual paired comparison, binding of a visuomotor response) can be mediated by structures external to hippocampus. Thus, a complete examination of memory development will have to rule out cortex as a source of early memory competency. We propose that early memory must show properties associated with full function of the trisynaptic circuit to reflect "adult-like" memory function, mainly (1) rapid encoding of contextual details of overlapping patterns, and (2) retention of these details over sleep-dependent delays. A wealth of evidence suggests that these functions are not apparent until 18-24 months, with behavioral discontinuities reflecting shifts in the neural structures subserving memory beginning approximately at this point in development. We discuss the implications of these observations for theories of memory and for identifying and measuring memory function in populations with typical and atypical hippocampal function.

Negative Affectivity Moderates Associations between Cumulative Risk and At-Risk Toddlers' Behavior Problems

This study examined cumulative risk, temperament traits, and their interplay as predictors of internalizing, externalizing, and sleep problems in at-risk toddlers. Participants were 104 low-income mother-toddler dyads recruited from Women, Infants, and Children (WIC) sites in a large city. The sample was primarily African American, and mothers were 21 years of age or younger at the child's birth. The dyads were assessed when the toddlers were approximately 18 months old and again at 24 months of age. Though all toddlers were from low-income families with young mothers, the families varied in the degree to which other contextual risk factors were present. A cumulative risk index was calculated based on five contextual factors: maternal education, neighborhood dangerousness, social support, household overcrowding and single parenting. In multiple regressions, cumulative risk predicted sleep and externalizing problems. In addition, negative affectivity predicted all three domains of problem behaviors, effortful control predicted fewer externalizing problems, and surgency predicted fewer internalizing problems. Moreover, low negative affectivity buffered the association between cumulative risk and both internalizing and sleep problems. These findings suggest that it is important to consider children's temperament traits in conjunction with the constellation of family risks when designing prevention programs to reduce the prevalence of behavior problems early in life.

The relationship between prior night's sleep and measures of infant imitation

We examined whether sleep quality during the night and naps during the day preceding a learning event are related to memory encoding in human infants. Twenty-four 6- and twenty-four 12-month-old infants' natural sleeping behavior was monitored for 24 hr using actigraphy. After the recording period, encoding was assessed using an imitation paradigm. In an initial baseline phase, infants were allowed to interact with the stimulus to assess spontaneous production of any target actions. Infants then watched an experimenter demonstrate a sequence of three target actions and were immediately given the opportunity to reproduce the demonstrated target actions to assess memory encoding. Analyses revealed significant correlations between nighttime sleep quality variables (sleep efficiency, sleep fragmentation) and immediate imitation in 6-month-olds, but not in 12-month-olds. High sleep quality in the preceding night was thus positively associated with next day's memory encoding in 6-month-old infants.

Reactivity and sleep in infants: a longitudinal objective assessment

Sleep patterns and temperament in the first year of life are closely related. However, research utilizing objective, rather than subjective measurements of sleep and temperament is scarce and results are inconsistent. In addition, a relative lack of longitudinal data prevents inference of causality between the two constructs. In this study, infant sleep was objectively assessed among 95 infants at 3, 6, and 12 months-of-age with an actigraph in the home setting. Reactivity to sound, light, and touch, a specific aspect of temperament, was behaviorally assessed at 3 and 6 months, both during sleep (at home) and during waking (at the laboratory). Expected maturational trends were recorded in sleep, with a temporal increase in sleep efficiency and percent of motionless sleep. Quadratic (i.e., inverse U shape) relations were found, especially among girls, when predicting change in sleep by reactivity thresholds, suggesting that both hyposensitive and hypersensitive infants are at risk for poor sleep quality. These are the first research findings suggesting that low reactivity in infancy might be associated with compromised sleep quality. The observed nonlinear effects may account for null or inconsistent results in previous studies that explored only linear associations between temperament and sleep. Future studies should address both extremes of the temperament continuum when exploring relations with sleep patterns.

Sleep as a mirror of developmental transitions in infancy: the case of crawling

The associations between the onset of crawling and changes in sleep were examined in 28 infants who were followed from 5 to 11 months-of-age. Motor development and sleep (actigraphy) were assessed at 2- to 3-week intervals. Along with the overall improvement in sleep consolidation, periods of increased long wake episodes were also manifested; the rise in sleep disruption was temporally linked to crawling onset. The results of the study highlight the dynamic interrelations between domains of development, indicate that emerging motor skills may involve periods of disrupted sleep, and point to the moderating effect of age. Clarifying the factors involved in the interplay between developmental milestones and sleep remains a challenge for future research.

Rourke Baby Record 2014: Evidence-based tool for the health of infants and children from birth to age 5

OBJECTIVE

To update the 2011 edition of the Rourke Baby Record (RBR) by reviewing current best evidence on health supervision of infants and children from birth to 5 years of age.

QUALITY OF EVIDENCE

The quality of evidence was rated with the former (until 2006) Canadian Task Force on Preventive Health Care classification system and GRADE (grading of recommendations, assessment, development, and evaluation) approach.

MAIN MESSAGE

New evidence has been incorporated into the 2014 RBR recommendations related to growth monitoring, nutrition, education and advice, development, physical examination, and immunization. Growth is monitored with the World Health Organization growth charts that were revised in 2014. Infants' introduction to solid foods should be based on infant readiness and include iron-containing food products. Delaying introduction to common food allergens is not currently recommended to prevent food allergies. At 12 months of age, use of an open cup instead of a sippy cup should be promoted. The education and advice section counsels on injuries from unstable furniture and on the use of rear-facing car seats until age 2, and also includes information on healthy sleep habits, prevention of child maltreatment, family healthy active living and sedentary behaviour, and oral health. The education and advice section has also added a new environmental health category to account for the effects of environmental hazards on child health. The RBR uses broad developmental surveillance to recognize children who might be at risk of developmental delays. Verifying tongue mobility and patency of the anus is included in the physical examination during the first well-baby visit. The 2014 RBR also provides updates regarding the measles-mumps-rubella, live attenuated influenza, and human papillomavirus vaccines.

CONCLUSION

The 2014 RBR is the most recent update of a longstanding evidence-based, practical knowledge translation tool with related Web-based resources to be used by both health care professionals and parents for preventive health care during early childhood. The 2014 RBR is endorsed by the Canadian Paediatric Society, the College of Family Physicians of Canada, and the Dietitians of Canada. National and Ontario versions of the RBR are available in English and French.

Sleep quality and temperament among university students: differential associations with nighttime sleep duration and sleep disruptions

Sleep-temperament associations have not yet been examined among university students, despite awareness of the high incidence of sleep problems in this population. The present study was conducted (a) to examine whether sleep quality was associated with temperament among university-attending young adults and (b) to determine whether particular components of sleep quality were differentially associated with temperament. University students completed questionnaires designed to assess sleep quality and temperament. Poor sleep quality was associated with increased negative affect and orienting sensitivity as well as decreased effortful control; regression analyses revealed differential associations between components of nighttime sleep quality and temperament ratings. The presented study reveals conceptual continuity in sleep-temperament relations from infancy to young adulthood and highlights important avenues for future research.

Assessment of sleep problems and related risk factors observed in Turkish children with Autism spectrum disorders

Sleep problems are common and difficult to manage in children with autism spectrum disorders (ASD). Another major adverse impact of sleep problems is that they exacerbate behavioral problems. To assess sleep problems and possible behavioral risk factors in detail, we aimed to compare sleep habits of children with ASD, with healthy children. The relationship between sleep difficulties and concomitant behavioral problems such as repetitive behaviors, hyperactivity, and social withdrawal were also examined. Hundred and seventeen children and adolescents including 64 with the diagnosis of ASD and 53 healthy subjects were enrolled in the study. Diagnostic Interview for ASD was performed according to DSM-IV-TR. Socio-demographical data form and childhood autism rating scale were filled by researchers. Aberrant behavior checklist (ABC), child behavior checklist and pediatric sleep questionnaire (PSQ) were completed by the parents of the children. Children with ASD had higher frequency of sleep problems, snoring, breathing problems, behavioral problems compared with healthy children (for all parameters; P < 0.001). A positive correlation was identified between the total score of PSQ and the total score of ABC (P < 0.05, Spearman correlation coefficient: 0.347). Sleep latency was prolonged in children with ASD compared with healthy subjects (P < 0.001). In accordance with the current literature, children with ASD were subject to sleep problems significantly more than the control group. Identified risk factors for sleep problems in ASD children were behavioral factors such as stereotypies, self-mutilation, hyperactivity, and social withdrawal. Autism Res 2016, 9: 536-542. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Effect of reducing sensory and environmental stimuli during hospitalized premature infant sleep

OBJECTIVETo compare the total sleep time of premature infant in the presence or absence of reducing sensory and environmental stimuli in the neonatal unit.METHODLongitudinal study in a Neonatal Intermediate Care Unit of a public hospital in Sao Paulo. The sample consisted of 13 premature infants. We used polysomnograph and unstructured observation for data collection. We analyzed 240 and 1200 minutes corresponding to the periods of the presence and absence of environmental management, respectively. Data were compared in proportion to the total sleep time in the two moments proposed by the study.RESULTSThe total sleep time in periods without environmental management was on average 696.4 (± 112.1) minutes and with management 168.5 (± 27.9) minutes, proportionally premature infant slept an average of 70.2% during periods with no intervention and 58.0% without management (p=0.002).CONCLUSIONReducing stimulation and handling of premature infant environment periods was effective to provide greater total sleep time.

Sleep as a window into early neural development: Shifts in sleep-dependent learning effects across early childhood

Sleep is an important physiological state for the consolidation and generalization of new learning in children and adults. We review the literature on sleep-dependent memory consolidation and generalization in infants and preschool children and place the findings in the context of the development of the neural systems underlying memory (hippocampus and its connections to cortex). Based on the extended trajectory of hippocampal development, transitions in the nature of sleep-dependent learning are expected. The studies reviewed here show shifts in the nature of sleep-dependent learning across early childhood, with sleep facilitating generalization in infants but enhancing precise memory after 18-24 months of age. Future studies on sleep-dependent learning in infants and young children must take these transitions in early brain development into account.

Evidence of developmental continuity from birth to 1 year: sleep, temperament, problem solving, and recognition memory

BACKGROUND

Research evidence is limited regarding developmentally appropriate care. Variations exits with respect to test procedure type, infant age at testing, and test relatedness.

PURPOSE

To assess developmental continuity using multiple developmental measures from birth to 12 months in a single cohort of term infants.

METHODS

A secondary analysis, longitudinal, correlational design was used to assess developmental continuity in a single cohort of infants (n 27). Measures included: sleep, using the Motility Monitoring System (first 48 hours of life); temperament, using the Infant Characteristics Questionnaire (ICQ, 6 months) and the Revised Infant Temperament Questionnaire (RITQ, 12 months); problem-solving, using the Willatts Infant Planning Test (PS, 9 and 12 months); and the Fagan Test of Infant Intelligence (FTII, 6 and 9 months).

RESULTS

Using Spearmen correlation, significant correlations included: (1) Sleep and ICQ: transitional sleep and "unpredictable" (r 0.455, P .017), "unadaptable" (r 0.420, P .026), and "dull" (r 0.416, P .028); (2) ICQ and FTII 6 months (r -0.512, P .008); (3) RITQ "approachability" and quiet sleep (r 0.662, P .005); (4) arousals in active sleep and PS at 9 months (r -0.528, P .016).

IMPLICATIONS FOR PRACTICE

Given our reported continuity between early sleep and later developmental measures, sleep-wake state should be considered in caregiving and environmental control to support sleep. Parental education on facilitating sleep-wake regulation in the home environment is essential.

IMPLICATIONS FOR RESEARCH

These data support the existence of continuity between early sleep and later developmental milestones warranting a larger-scale investigation. Specific focus on development of care strategies for facilitating sleep immediately following birth is warranted.

Associations between infant temperament, maternal stress, and infants' sleep across the first year of life

Effects of temperament and maternal stress on infant sleep behaviors were explored longitudinally. Negative temperament was associated with sleep problems, and with longer sleep latency and night wakefulness, whereas maternal stress was associated with day sleep duration, suggesting infant and maternal characteristics affect sleep differentially.

Association between delayed bedtime and sleep-related problems among community-dwelling 2-year-old children in Japan

Background

Although delayed sleep timing causes many socio-psycho-biological problems such as sleep loss, excessive daytime sleepiness, obesity, and impaired daytime neurocognitive performance in adults, there are insufficient data showing the clinical significance of a ‘night owl lifestyle’ in early life. This study examined the association between habitual delayed bedtime and sleep-related problems among community-dwelling 2-year-old children in Japan.

Methods

Parents/caregivers of 708 community-dwelling 2-year-old children in Nishitokyo City, Tokyo, participated in the study. The participants answered a questionnaire to evaluate their child’s sleep habits and sleep-related problems for the past 1 month.

Results

Of the 425 children for whom complete data were collected, 90 (21.2%) went to bed at 22:00 or later. Children with delayed bedtime showed significantly more irregular bedtime, delayed wake time, shorter total sleep time, and difficulty in initiating and terminating sleep. Although this relationship indicated the presence of sleep debt in children with delayed bedtime, sleep onset latency did not differ between children with earlier bedtime and those with delayed bedtime. Rather, delayed bedtime was significantly associated with bedtime resistance and problems in the morning even when adjusting for nighttime and daytime sleep time.

Conclusions

Even in 2-year-old children, delayed bedtime was associated with various sleep-related problems. The causal factors may include diminished homeostatic sleep drive due to prolonged daytime nap as well as diurnal preference (morning or night type) regulated by the biological clock.

Behavioral observation differentiates the effects of an intervention to promote sleep in premature infants: a pilot study

PURPOSE

Sleep and ongoing cycling of sleep states are required for neurosensory processing, learning, and brain plasticity. Many aspects of neonatal intensive care environments such as handling for routine and invasive procedures, bright lighting, and noise can create stress, disrupt behavior, and interfere with sleep in prematurely born infants. The study empirically investigated whether a 30-minute observation of infant sleep states and behavior could differentiate an intervention to promote sleep in premature infants with feeding difficulties relative to conventional care (standard positioning, standard crib mattress [SP]). We included an intervention to determine the ability of the method to discriminate treatments and generate a benchmark for future improvements. The intervention, a conformational positioner (CP), is contoured around the infant to provide customized containment and boundaries. To more fully verify the 30-minute observational sleep results, standard polysomnography was conducted simultaneously and sleep outcomes for the 2 modalities were compared.

SUBJECTS

In a randomized crossover clinical trial, 25 infants, 31.5 ± 0.6 weeks' gestational age and 38.4 ± 0.6 weeks at the study, with gastrointestinal conditions or general feeding difficulties used each intervention during an overnight neonatal intensive care unit sleep study.

METHODS

Infant sleep states and behaviors were observed during two 30-minute periods--that is, on the positioner and mattress--using the naturalistic observation of newborn behavior. Two certified developmental care nurses assessed sleep state, self-regulatory, and stress behaviors during 2-minute intervals and summed over 30 minutes. Sleep characteristics from standard polysomnography were measured at the time of behavior observations.

RESULTS

Infants on CP spent significantly less time in alert, active awake, or crying states by observation compared with SP. Surgical subjects spent more time awake, active awake, or crying and displayed a higher number of behavior state changes than the nonsurgical infants. The percentage of time in observed deep sleep and quiet sleep was correlated with both percentage sleep efficiency (r = 0.78) and fewer state shifts per hour (r = -0.65) from electroencephalogram (EEG). Sleep efficiency by EEG was greater on CP versus SP.

CONCLUSIONS

The CP enabled sleep compared with the standard mattress (SP) over 30-minute observation periods. Sleep status from behavioral observation was verified by standard EEG-based sleep techniques. Behavioral observation of sleep states may be a useful strategy for measuring the effectiveness of strategies to facilitate sleep in premature infants. Surgical subjects may benefit from additional interventions to promote sleep.

Conformational positioning improves sleep in premature infants with feeding difficulties

OBJECTIVE

To determine whether premature infants' sleep organization, total sleep time, and arousals may be modulated while on a conformational positioner that provides boundaries, customized positioning, and containment compared with standard positioning (standard crib mattress).

STUDY DESIGN

A proof of concept trial using a within subject crossover design was conducted among 25 premature infants with feeding difficulties. Infants of 31.5 weeks gestational age served as their own control during overnight polysomnography at postconceptual age 38.4 weeks. Each baby received both interventions (order randomized), 1 for each one-half of the 10.5-hour study.

RESULTS

Use of the conformational positioner resulted in higher sleep efficiency of 61% vs 54% for the standard mattress (P < .05). The interventions did not differ for percent active sleep, percent quiet sleep, percent indeterminate sleep, or spontaneous arousals. Sleep efficiency was higher on the conformational positioner than standard positioning for surgical subjects and for subjects with necrotizing enterocolitis or gastroschisis (n = 10). The surgical subjects (n = 9) had lower sleep efficiency, lower percentage of active sleep, and more spontaneous arousals compared with the nonsurgical group.

CONCLUSIONS

The use of the conformational positioner improved sleep efficiency vs the standard mattress in premature infants with feeding difficulties. Infants requiring surgery or with gastrointestinal diagnoses may be more susceptible to environmental stress.

Sleep in infancy predicts gender specific social-emotional problems in toddlers

Despite strong evidence linking sleep to developmental outcomes, the longitudinal relationship between sleep and emotional well-being remains largely unknown. To address this gap in our knowledge, the current study examined sleep in infancy, measured via actigraphy, as a predictor of social-emotional problems in toddlers. A total of 47 children (29 males) were included in this longitudinal study. At time one, actigraphy measures of sleep were obtained from 3- to 4-month-old infants. At time two, parents rated their 18- to 24-month-old toddler's social-emotional well-being using the Brief Infant Toddler Social Emotional Assessment. Results indicated that boys tended to have higher levels of externalizing behaviors than did girls. Additionally, boys with longer sleep durations also showed lower sleep efficiency. In girls, sleep duration in infancy was a significant predictor of autism spectrum disorder behaviors and approached significance as a predictor of externalizing problems in toddlerhood. Our findings are the first to show a relationship between sleep measured in infancy and autism spectrum disorder symptomatology measured in early childhood. They suggest that the etiology of social-emotional problems may differ between genders and raise the possibility that sleep/wake cycles may be differentially related to autism spectrum disorder symptoms in girls and boys.

Development: better sleep on it, children

A new study has identified a neural circuit that is responsible for increasing sleep in young fruit flies. Reduced dopamine signaling to the fan-shaped body during early life promotes sleep and is critical for proper brain development.

A critical period of sleep for development of courtship circuitry and behavior in Drosophila

Most animals sleep more early in life than in adulthood, but the function of early sleep is not known. Using Drosophila, we found that increased sleep in young flies was associated with an elevated arousal threshold and resistance to sleep deprivation. Excess sleep results from decreased inhibition of a sleep-promoting region by a specific dopaminergic circuit. Experimental hyperactivation of this circuit in young flies results in sleep loss and lasting deficits in adult courtship behaviors. These deficits are accompanied by impaired development of a single olfactory glomerulus, VA1v, which normally displays extensive sleep-dependent growth after eclosion. Our results demonstrate that sleep promotes normal brain development that gives rise to an adult behavior critical for species propagation and suggest that rapidly growing regions of the brain are most susceptible to sleep perturbations early in life.

Impact of NICU design on environmental noise

For neonates requiring intensive care, the optimal sound environment is uncertain. Minimal disruptions from medical staff create quieter environments for sleep, but limit language exposure necessary for proper language development. There are two models of neonatal intensive care units (NICUs): open-bay, in which 6-to-10 infants are cared for in a single large room; and single-room, in which neonates are housed in private, individual hospital rooms. We compared the acoustic environments in the two NICU models. We extracted the audio tracks from video-electroencephalography (EEG) monitoring studies from neonates in an open-bay NICU and compared the acoustic environment to that recorded from neonates in a new single-room NICU. From each NICU, 18 term infants were studied (total N=36; mean gestational age 39.3±1.9 weeks). Neither z-scores of the sound level variance (0.088±0.03 vs. 0.083±0.03, p=0.7), nor percent time with peak sound variance (above 2 standard deviations; 3.6% vs. 3.8%, p=0.6) were different. However, time below 0.05 standard deviations was higher in the single-room NICU (76% vs. 70%, p=0.02). We provide objective evidence that single-room NICUs have equal sound peaks and overall noise level variability compared with open-bay units, but the former may offer significantly more time at lower noise levels.

Behavioral sleep interventions in the first six months of life do not improve outcomes for mothers or infants: a systematic review

OBJECTIVE

The United Kingdom's National Institute for Health Research has recently invited proposals for the design of a multicomponent primary care package of behavioral interventions to reduce parental distress caused by excessive infant crying in the first 6 months of life. A systematic review was performed to determine whether behavioral interventions for sleep, when applied by parents to infants younger than 6 months, improve maternal and infant outcomes.

METHODS

Searches of PubMed, CINAHL, and Cochrane Database of Systematic Reviews were conducted to identify systematic reviews, meta-analyses, clinical trials, and cohort studies investigating the effects of behavioral sleep interventions in infants younger than 6 months (January 1993-March 2013). The evidence is critically analyzed, according to PRISMA guidelines.

RESULTS

Cry-fuss, feeding, and sleep problems emerge out of multiple dynamically interacting and co-evolving variables in early life and are for this reason generically referred to as regulatory problems. Studies that link behavioral interventions for sleep in the first 6 months with positive effects on maternal and infant health demonstrate 3 methodological constraints. They fail to identify and control for feeding difficulties, fail to distinguish between the neurodevelopmentally different first and second halves of the first year of life, and apply reductive analyses to evaluations of complex interventions. Despite substantial investment in recent years in implementation and evaluation of behavioral interventions for infant sleep in the first 6 months, these strategies have not been shown to decrease infant crying, prevent sleep and behavioral problems in later childhood, or protect against postnatal depression. In addition, behavioral interventions for infant sleep, applied as a population strategy of prevention from the first weeks and months, risk unintended outcomes, including increased amounts of problem crying, premature cessation of breastfeeding, worsened maternal anxiety, and, if the infant is required to sleep either day or night in a room separate from the caregiver, an increased risk of SIDS.

CONCLUSION

The belief that behavioral intervention for sleep in the first 6 months of life improves outcomes for mothers and babies is historically constructed, overlooks feeding problems, and biases interpretation of data.

Temperamental characteristics in childhood migraine without aura: a multicenter study

BACKGROUND

Children with migraine seem to be more anxious, sensitive, deliberate, cautious, fearful, vulnerable to frustration, tidy, and less physically enduring than comparisons. To the best our knowledge no studies about the temperamental and the characterial dimension aspects in childhood migraine was conducted. Therefore, the aim of the present study was to describe the temperamental and character aspects in a sample of children affected by migraine without aura (MoA) and their relationship with clinical aspects of MoA such as frequency, duration, and severity of attacks.

MATERIALS AND METHODS

In our study, 486 children affected by MoA (239 male, 247 female) aged 7-12 years, (mean 10.04 ± 2.53 years) and 518 typical developing children comparable for age (P = 0.227) and sex (P = 0.892) were enrolled to assess their temperamental characteristics. The mothers of all subjects filled out the Junior Temperament and Character Inventory: Parent Version.

RESULTS

Children affected by migraine show a higher prevalence of harm avoidance and persistence temperamental domains (P < 0.001) and significantly lower prevalence of the self-directedness character trait (P = 0.023) with respect to the comparisons, according to Cloninger's model. The Spearman rank correlation analysis shows a significant relationship between migraine characteristics and temperamental domains.

CONCLUSION

The present study first identified differences in temperamental characteristics in children affected by MoA with respect to the comparisons, suggesting the need for this evaluation in order for better psychological pediatric management of children with migraine, with possible consequences and impact on the future outcomes of these subjects.

Sleep and Attachment in Preterm Infants

Infants born preterm are at elevated risk for social emotional difficulties. However, factors contributing to this risk are largely understudied. Within the present study, we explored infant sleep as a biosocial factor that may play a role in infant social emotional development. Within a prospective longitudinal design, we examined parent-reported sleep patterns and observed parenting quality as predictors of infant-mother attachment in 171 infants born preterm. Using structural equation modeling, we examined main effect and moderator models linking infant sleep patterns and parenting with attachment security. Sleep patterns characterized by more daytime sleep and positive/responsive parenting predicted infant attachment security. Parent-reported nighttime sleep patterns were unrelated to attachment in this sample of infants born preterm. These results indicate that daytime sleep and parenting quality may be important for emerging attachment relationships in infants born preterm.

Sleep measurement and monitoring in children with Down syndrome: a review of the literature, 1960-2010

Children with Down syndrome (DS) are at risk for sleep disturbances due to the anatomical features of the syndrome. Over the past 50 years research studies have measured sleep in children with DS to characterize sleep architecture and its relation to developmental delay. In the 1980s sleep disordered breathing (SDB) was recognized as a major cause of sleep disturbance in DS. The aim of this comprehensive review is to synthesize studies and present the historical context of evolving technologies, methodologies, and knowledge about SDB and DS. Future research opportunities and practice implications are discussed.

Sleep problems and early developmental delay: implications for early intervention programs

Sleep disorders negatively impact behavior, cognition, and growth--the same areas targeted by early intervention. Conversely, developmental delays and disabilities may themselves precipitate sleep disorders. Young children with developmental delays experience sleep disorders at a higher rate than do typically developing children; the most common types are difficulties initiating or maintaining sleep and sleep disordered breathing. To date, attention has been focused on sleep problems in children with specific conditions (e.g., autism, genetic syndromes, prematurity, and seizure disorder). The authors review evidence of sleep problems' broader impact across the range of children screened for early intervention. Eligibility evaluations for early intervention address the five developmental domains: adaptive, motor, cognitive, communication, and socioemotional. Disordered sleep may be symptomatic of socioemotional and adaptive problems. Assessing sleep problems within the evaluation may help establish eligibility for early intervention services and would maximize developmental potential by ensuring timely identification, referral, and treatment.