Children born extremely preterm had different sleeping habits at 11 years of age and more childhood sleep problems than term-born children

Sleep characteristics and changes in sleep patterns among infants in Bhaktapur, Nepal

OBJECTIVE

Sleep undergoes major changes during the first year of life, but the characteristics of sleep among infants in low and middle-income countries are not well documented. This study describes sleep characteristics and changes in sleep patterns in infants at 6 and 12months of age from Bhaktapur, Nepal.

METHODS

This was a community-based longitudinal study comprising 735 infants. Sleep characteristics were obtained by interview with the mother using the Brief Infant Sleep Questionnaires. The stability of sleep duration and night awakenings were estimated by logistic regression analysis.

RESULTS

Cosleeping in the parent's bed at 6 and 12months of age was almost universal (>97%). At 6months of age, 254 (35%) and at 12months of age, 341 (46%) infants had a total 24-hour sleep duration <12 hours. Night awakenings >3 times per night were common (65%) both at 6 and 12months of age. Infants with frequent nightly awakenings at 6months had increased odds of frequent nightly awakenings at 12months (OR=2.2; 95% CI: 1.6, 2.9). Very few (<3%) mothers reported sleep problems in their infants at 6 and 12months of age.

CONCLUSIONS

Cosleeping was almost universal among Nepalese infants, and very few of the mothers reported sleep problems in their infants. Infants at 6 and 12months had similar patterns for both sleep duration and nocturnal awakenings. For infants, there were increased odds of having similar sleep duration and nocturnal awakening at 6 and 12months.

Comparison of actigraphy with a sleep protocol maintained by professional caregivers and questionnaire-based parental judgment in children and adolescents with life-limiting conditions

BACKGROUND

Actigraphy offers a promising way to objectively assess pediatric sleep. Aim of the study was investigating the extent to which actigraphy used in children and adolescents with life-limiting conditions is consistent with two other measures of sleep diagnostics.

METHODS

In this monocentric prospective study N = 26 children and adolescents with life-limiting conditions treated on a pediatric palliative care unit were assessed. For three consecutive nights they wore an actigraph; the 24-hours sleep protocol documented by nurses and the Sleep Screening for Children and Adolescents with Complex Chronic Conditions (SCAC) answered by parents were analyzed. Patient characteristics and the parameters sleep onset, sleep offset, wake after sleep onset (WASO), number of wake phases, total sleep time (TST) and sleep efficiency (SE) were descriptively examined. Percentage bend correlations evaluated the three measures' concordance.

RESULTS

Descriptively, and except for the number of waking episodes, the different measures' estimations were comparable. Significant correlations existed between actigraphy and the sleep protocol for sleep onset (r = 0.83, p = < 0.001) and sleep offset (r = 0.89, p = < 0.001), between actigraphy and SCAC for SE (r = 0.59, p = 0.02).

CONCLUSION

Agreement of actigraphy with the focused sleep measures seems to be basically given but to varying degrees depending on the considered parameters.

Combining Cardiorespiratory Signals and Video-Based Actigraphy for Classifying Preterm Infant Sleep States

The classification of sleep state in preterm infants, particularly in distinguishing between active sleep (AS) and quiet sleep (QS), has been investigated using cardiorespiratory information such as electrocardiography (ECG) and respiratory signals. However, accurately differentiating between AS and wake remains challenging; therefore, there is a pressing need to include additional information to further enhance the classification performance. To address the challenge, this study explores the effectiveness of incorporating video-based actigraphy analysis alongside cardiorespiratory signals for classifying the sleep states of preterm infants. The study enrolled eight preterm infants, and a total of 91 features were extracted from ECG, respiratory signals, and video-based actigraphy. By employing an extremely randomized trees (ET) algorithm and leave-one-subject-out cross-validation, a kappa score of 0.33 was achieved for the classification of AS, QS, and wake using cardiorespiratory features only. The kappa score significantly improved to 0.39 when incorporating eight video-based actigraphy features. Furthermore, the classification performance of AS and wake also improved, showing a kappa score increase of 0.21. These suggest that combining video-based actigraphy with cardiorespiratory signals can potentially enhance the performance of sleep-state classification in preterm infants. In addition, we highlighted the distinct strengths and limitations of video-based actigraphy and cardiorespiratory data in classifying specific sleep states.

Sleep disturbances are associated with feeding practices and age in preterm infants

BACKGROUND

Preterm infants are under risk of several shortcomings including sleep disturbances (SD). This cross-sectional study evaluated factors associated with SD in preterm and low birth weight infants in a reference center for preterm children at a University Hospital, southeastern Brazil.

METHODS

A hundred-four dyads of mothers-infants 0-3 years participated. Mothers answered an online questionnaire (Google Forms®) evaluating childbirth characteristics, gestational age, breastfeeding, bottle feeding, non-nutritive sucking habits and sociodemographic information. The Brazilian version of the Brief Infant Sleep Questionnaire (BISQ) evaluated SD. Bivariate and Logistic Regression analyses were performed (p < 0.05).

RESULTS

SD was present in 45.2% of the sample. Multivariate Logistic Regression Model showed that infants breastfed ≥3 times at night had 5.006 more chances to have SD (CI 95% = 1.229-20.400) compared to those who did not breastfeed at night. Infants who were bottle-fed 3 ≥ times at night had 6.952 more chances to have SD (CI = 95% = 1.364-35.427) compared to those who were bottle fed less frequently. The chance of SD decreased 6.6% (CI 95% = 0.889-0.982) for each increase of a month in infant's age, and infants from families with higher income had 3.535 more chances to have SD (CI 95% = 1.006-12.416).

CONCLUSION

The younger the child, a higher frequency of night feeding and belonging to higher income families were associated with SD. Recognizing the associated factors with SD in newborns and infants can aid families to better deal with this issue, promote better sleep quality and individualized counseling.

Sleep and 24-hour rhythm characteristics in preschool children born very preterm and full term

STUDY OBJECTIVES

Sleep impacts the quality of life and is associated with cardiometabolic and neurocognitive outcomes. Little is known about the sleep of preterm-born children at preschool age. We, therefore, studied sleep and 24-hour rhythms of preschool children born very preterm compared with full-term children.

METHODS

This was a prospective cohort study comparing sleep quality and quantity of children born very preterm (gestational age [GA] < 30 weeks) with full-term children at the (corrected) age of 3 years, using (1) 2 parent-reported questionnaires (Brief Infant Sleep Questionnaire and The Munich Chronotype Questionnaire) and (2) at least 3 days of triaxial wrist actigraphy combined with sleep diary. We performed regression analyses with adjustment for sex (corrected), age, and birth weight standard deviation (SD) score.

RESULTS

Ninety-seven very-preterm-born (median GA 27+5; interquartile range 26 + 3;29 + 0 weeks) and 92 full-term children (GA 39 + 3; 38 + 4;40 + 4 weeks) were included. Sleep problems and other reported sleep parameters were not different between groups. As measured with actigraphy, sleep and 24-hour rhythm were similar between groups, except for very-preterm born children waking up 21 minutes (4;38) minutes later than full-term children (adjusted P = .001).

CONCLUSIONS

Based on parent reports and actigraphy, very-preterm-born children sleep quite similar to full-term controls at the corrected age of 3 years. Reported sleep problems were not different between groups. Actigraphy data suggest that preterm-born children may wake up later than children born full term. Further studies are needed to explore how sleep relates to cardiometabolic and neurodevelopmental outcomes after preterm birth and whether early interventions are useful to optimize 24-hour rhythm and sleep.

CITATION

Bijlsma A, Beunders VAA, Dorrepaal DJ, et al. Sleep and 24-hour rhythm characteristics in preschool children born very preterm and full term. J Clin Sleep Med. 2023;19(4):685-693.

Development and preliminary validation of the Sleep Screening for Children and Adolescents with Complex Chronic Conditions (SCAC)

Children and adolescents with complex chronic conditions, including those with life-threatening or life-limiting conditions, are a heterogeneous population. Many individuals exhibit sleep abnormalities that are measurable by proxy questionnaires. No suitable instrument to assess the wide range of different complex chronic conditions is currently available. The aim of the present study was to develop a screening tool-the Sleep Screening for Children and Adolescents with Complex Chronic Conditions-to effectively obtain sleep behaviour information in this population. Following a mixed-method design, potential items for the Sleep Screening for Children and Adolescents with Complex Chronic Conditions questionnaire were defined through literature research and expert meetings. In a pre-test with N = 60 family and professional caregivers, the items' relevance and comprehensibility as well as the instrument's overall design were assessed. For the main test, N = 315 participants were recruited in three tertiary paediatric hospitals. A principal components analysis detected the questionnaire's scales. Item analysis focused on mean values, range, difficulty and discriminatory power. Convergent validation of the Sleep Screening for Children and Adolescents with Complex Chronic Conditions was assessed via correlations between scale items. Most patients had neurological or neuromuscular diseases. Four scales ("Falling and staying asleep", "Sleep-associated respiration and arousal", "Daytime sleepiness" and "Sleep-associated movements") emerged. The item analysis showed satisfactory discriminative power. In the preliminary validation, all scales correlated positively with a child's care level and with various sleep circumstances items. Three scales additionally correlated with the number of complex chronic condition diagnoses. This newly developed questionnaire can provide clinicians with first indications of possible sleep problems in a growing paediatric population.

Fetal and infant growth patterns, sleep, and 24-h activity rhythms: a population-based prospective cohort study in school-age children

The study objective was to explore associations of fetal and infant weight patterns and preterm birth with sleep and 24-h activity rhythm parameters at school-age. In our prospective population-based study, 1327 children were followed from birth to age 10-15 years. Fetal weight was estimated using ultrasound in the second and third trimester of pregnancy. Birth weight and gestational age were available from midwife registries. Infant weight was measured at 6, 12 and 24 months. Fetal and infant weight acceleration or deceleration were defined as a change of >0.67 standard deviation between the corresponding age intervals. At school-age, sleep duration, sleep efficiency, wake after sleep onset, social jetlag, inter-daily stability, and intra-daily variability were assessed using tri-axial wrist actigraphy for 9 consecutive nights. We observed that low birth weight (<2500 g) was associated with 0.24 standard deviation (95% confidence interval [CI] 0.04; 0.43) longer sleep duration compared to normal weight. Compared to normal growth, growth deceleration in fetal life and infancy was associated with 0.40 standard deviation (95% CI 0.07; 0.73) longer sleep duration, 0.44 standard deviation (95% CI 0.14; 0.73) higher sleep efficiency, and -0.41 standard deviation (95% CI -0.76; -0.07) shorter wake after sleep onset. A pattern of normal fetal growth followed by infant growth acceleration was associated with -0.40 standard deviation (95% CI -0.61; -0.19) lower inter-daily stability. Preterm birth was not associated with any sleep or 24-h rhythm parameters. Our findings showed that children with fetal and infant growth restriction had longer and more efficient sleep at school-age, which may be indicative of an increased need for sleep for maturational processes and development after a difficult start in life.

Sleep assessment in preterm infants: Use of actigraphy and aEEG

OBJECTIVE

Objective methods to monitor the sleep of preterm infants at the neonatal intensive care unit (NICU) are required to prevent potentially adverse neurodevelopmental outcomes. This study aimed to determine the concordance of actigraphy and amplitude-integrated electroencephalogram (aEEG) against gold standard direct observation (DO) in assessing sleep/wake states of typically developing preterm infants.

METHODS

This prospective observational study was conducted in a single center level III NICU. Sleep variables were measured using Philips Respironics Mini-Mitter® Actiwatch-2 for 24 h and compared with 8-h matched data of aEEG and DO. Sensitivity-specificity analysis, Cohen's kappa, prevalence-adjusted and bias-adjusted kappa (PABAK), and Bland Altman plots were generated.

RESULTS

Seventeen preterm infants were recruited. A total of 11252 epochs were studied. Sensitivity (86.4%), agreement rate (67.9%), and predictive value for wake (47.9%) for the actigraphy were highest at the automatic activity threshold whereas specificity (54.5%) and predictive value for sleep (75.5%) were highest at low threshold. The sensitivity of aEEG was 79.3% and the specificity was 54.3%. At all thresholds, the agreement was largely equivalent with low kappas (0.14-0.17) and PABAK coefficients (0.22-0.35) for actigraphy and DO. Moderate agreement was observed between aEEG and DO according to the PABAK coefficient (0.44). Mean differences in sleep parameters were not different between DO and aEEG as well as DO/aEEG and actigraphy at medium threshold (p > 0.05).

CONCLUSIONS

Actigraphy at medium threshold can be used in depicting sleep in typically developing preterm infants at NICU. aEEG may be an alternative adjunctive method to actigraphy for the evaluation of sleep/wake states in the NICU setting.

CLINICAL TRIAL REGISTRATION NUMBER

NCT04145362.

Cot-side imaging of functional connectivity in the developing brain during sleep using wearable high-density diffuse optical tomography

Studies of cortical function in newborn infants in clinical settings are extremely challenging to undertake with traditional neuroimaging approaches. Partly in response to this challenge, functional near-infrared spectroscopy (fNIRS) has become an increasingly common clinical research tool but has significant limitations including a low spatial resolution and poor depth specificity. Moreover, the bulky optical fibres required in traditional fNIRS approaches present significant mechanical challenges, particularly for the study of vulnerable newborn infants. A new generation of wearable, modular, high-density diffuse optical tomography (HD-DOT) technologies has recently emerged that overcomes many of the limitations of traditional, fibre-based and low-density fNIRS measurements. Driven by the development of this new technology, we have undertaken the first cot-side study of newborn infants using wearable HD-DOT in a clinical setting. We use this technology to study functional brain connectivity (FC) in newborn infants during sleep and assess the effect of neonatal sleep states, active sleep (AS) and quiet sleep (QS), on resting state FC. Our results demonstrate that it is now possible to obtain high-quality functional images of the neonatal brain in the clinical setting with few constraints. Our results also suggest that sleep states differentially affect FC in the neonatal brain, consistent with prior reports.

Preterm toddlers have low nighttime sleep quality and high daytime activity

A number of studies have been made on the sleep characteristics of children born preterm in an attempt to develop methods to address the sleep problems commonly observed among such children. However, the reported sleep characteristics from these studies vary depending on the observation methods used, i.e., actigraphy, polysomnography and questionnaire. In the current study, to obtain reliable data on the sleep characteristics of preterm-born children, we investigated the difference in sleep properties between 97 preterm and 97 term toddlers of approximately 1.5 years of age using actigraphy. Actigraphy units were attached to the toddlers' waists with an adjustable elastic belt for 7 consecutive days, and a child sleep diary was completed by their parents. In the study, we found that preterm toddlers had more nocturnal awakenings and more daytime activity, suggesting that preterm-born children may have a different process of sleep development in their early development.

Sleep problems in infancy and early school age in very preterm infants

BACKGROUND

Sleep plays an important role for psychological and physical health, especially in infants at high risk for long-term neurodevelopmental impairment such as preterm infants.

OBJECTIVE

Our study aimed at determining risk factors for long-term sleep impairment in very-preterm (VPT; <32 weeks of gestation) infants.

METHODS

Sleep problems were analyzed in an observational study in infants of the German Neonatal Network born between January 1st 2009 and December 31st 2014. Parental questionnaires of n = 2928 VPT children were evaluated regarding the child's sleep behavior at five years of age. Univariate and logistic regression analyses were used to identify risk factors for delayed sleep onset and hyperactivity/inattention (Strength and Difficulties Questionnaire). In a second cohort of n = 342 VPT infants, sleep habits were evaluated at toddlers age via the Infant Sleep Questionnaire.

RESULTS

In our cohorts, 424/2928 (14.5 %) preterm children were diagnosed with delayed sleep onset at early school age while 57/342 (16.7 %) had sleep impairment in early infancy. Gestational age was not independently associated with sleep problems (i.e., early school age: OR 0.97, 95 % CI 0.9-1.1, p = 0.15). Notably, in both our cohorts, neonatal exposure to analgesics and sedatives was associated with a higher risk for sleep problems, i.e., early school age: exposure to sedatives: OR 1.31, 95%CI 1.02-1.7, p = 0.03. Sleep problems and drug exposure were both associated with hyperactivity/inattention.

CONCLUSION

Sleep problems of VPT children are unrelated to gestational age which suggests rather individual risk factors. The significant neonatal exposure to analgesics and sedatives may contribute to long-term sleep impairment.

Associations between gestational age and childhood sleep: a national retrospective cohort study

BACKGROUND

Both sleep quality and quantity are essential for normal brain development throughout childhood; however, the association between preterm birth and sleep problems in preschoolers is not yet clear, and the effects of gestational age across the full range from preterm to post-term have not been examined. Our study investigated the sleep outcomes of children born at very-preterm (<31 weeks), moderate-preterm (32-33 weeks), late-preterm (34-36 weeks), early-term (37-38 weeks), full-term (39-40 weeks), late-term (41 weeks) and post-term (>41 weeks).

METHODS

A national retrospective cohort study was conducted with 114,311 children aged 3-5 years old in China. Children's daily sleep hours and pediatric sleep disorders defined by the Children's Sleep Habits Questionnaire (CSHQ) were reported by parents. Linear regressions and logistic regression models were applied to examine gestational age at birth with the sleep outcomes of children.

RESULTS

Compared with full-term children, a significantly higher CSHQ score, and hence worse sleep, was observed in very-preterm (β = 1.827), moderate-preterm (β = 1.409), late-preterm (β = 0.832), early-term (β = 0.233) and post-term (β = 0.831) children, all p<0.001. The association of pediatric sleep disorder (i.e. CSHQ scores>41) was also seen in very-preterm (adjusted odds ratio [AOR] = 1.287 95% confidence interval [CI] (1.157, 1.433)), moderate-preterm (AOR = 1.249 95% CI (1.110, 1.405)), late-preterm (AOR = 1.111 95% CI (1.052, 1.174)) and post-term (AOR = 1.139 95% CI (1.061, 1.222)), all p<0.001. Shorter sleep duration was also found in very-preterm (β = -0.303), moderate-preterm (β = -0.282), late-preterm (β = -0.201), early-term (β = -0.068) and post-term (β = -0.110) compared with full-term children, all p<0.01. Preterm and post-term-born children had different sleep profiles as suggested by subscales of the CSHQ.

CONCLUSIONS

Every degree of premature, early-term and post-term birth, compared to full-term, has an association with sleep disorders and shortened daily sleep duration. Preterm, early-term, and post-term should therefore all be monitored with an increased threat of sleep disorder that requires long-term monitoring for adverse sleep outcomes in preschoolers.

The Impact of Preterm Birth on Sleep through Infancy, Childhood and Adolescence and Its Implications

There is emergent literature on the relationship between the development of sleep-wake cycles, sleep architecture, and sleep duration during the neonatal period on neurodevelopmental outcomes among children born preterm. There is also a growing literature on techniques to assess sleep staging in preterm neonates using either EEG methods or heart and respiration rate. Upon discharge from hospital, sleep in children born preterm has been assessed using parent report, actigraphy, and polysomnography. This review describes the ontogeny and measurement of sleep in the neonatal period, the current evidence on the impact of preterm birth on sleep both in the NICU and in childhood and adolescence, and the interaction between sleep, cognition, and social-emotional outcomes in this population.

Early development of sleep and brain functional connectivity in term-born and preterm infants

The proper development of sleep and sleep-wake rhythms during early neonatal life is crucial to lifelong neurological well-being. Recent data suggests that infants who have poor quality sleep demonstrate a risk for impaired neurocognitive outcomes. Sleep ontogenesis is a complex process, whereby alternations between rudimentary brain states-active vs. wake and active sleep vs. quiet sleep-mature during the last trimester of pregnancy. If the infant is born preterm, much of this process occurs in the neonatal intensive care unit, where environmental conditions might interfere with sleep. Functional brain connectivity (FC), which reflects the brain's ability to process and integrate information, may become impaired, with ensuing risks of compromised neurodevelopment. However, the specific mechanisms linking sleep ontogenesis to the emergence of FC are poorly understood and have received little investigation, mainly due to the challenges of studying causal links between developmental phenomena and assessing FC in newborn infants. Recent advancements in infant neuromonitoring and neuroimaging strategies will allow for the design of interventions to improve infant sleep quality and quantity. This review discusses how sleep and FC develop in early life, the dynamic relationship between sleep, preterm birth, and FC, and the challenges associated with understanding these processes. IMPACT: Sleep in early life is essential for proper functional brain development, which is essential for the brain to integrate and process information. This process may be impaired in infants born preterm. The connection between preterm birth, early development of brain functional connectivity, and sleep is poorly understood. This review discusses how sleep and brain functional connectivity develop in early life, how these processes might become impaired, and the challenges associated with understanding these processes. Potential solutions to these challenges are presented to provide direction for future research.

Prevalence of Sleep Problems and Its Association With Preterm Birth Among Kindergarten Children in a Rural Area of Shanghai, China

INTRODUCTION

Healthy sleep in children is critical for their physical and mental health. Although growing evidence indicates the linkage between preterm birth and neural network that regulates sleep architecture, findings on the association between preterm birth and sleep problems among children are still contradictory. In this study, we aimed to understand the prevalence of sleep problems in children aged 3-6 years and to explore the association between sleep problems and preterm birth among children in Shanghai, China.

METHODS

We selected 8,586 kindergarten children aged 3-6 years and their mothers in a rural area of Shanghai. Data were collected by questionnaire interview among mothers with informed consent that was signed ahead. Six types of sleep problems (i.e., insufficient sleep, sleepwalk, nightmare, snore, grind teeth, and cry in sleep) were selected in this study. SAS 9.4 was used for data analysis, and p < 0.05 was considered statistically significant.

RESULTS

In this study, the prevalence of preterm birth was 9.88% (848/8,586), with a higher prevalence in boys (10.62%) than girls (9.01%). The prevalence of sleep problems was 89.81% among kindergarten children, with 62.50% for snore, 50.35% for grind teeth, 49.20% for cry in sleep, 41.18% for nightmare, 11.67% for insufficient sleep, and 4.44% for sleepwalk. The age of children, family income, and mother's education were associated with the prevalence of sleep problems in children. Logistic regression indicated that sleep problems in preterm children were comparable with the full-term children [odds ratio = 1.13, 95% confidence interval (0.89-1.45)].

CONCLUSION

Sleep problems were prevalent among children aged 3-6 years in the rural area of Shanghai, and preterm birth was not associated with sleep problems in kindergarten children. We recommend that parents should create limit setting in the home, cultivate similar child-rearing attitudes and beliefs among family members, and encourage children to go to bed earlier.

Sleep problems in preschool children at the child development center with different developmental status: A questionnaire survey

OBJECTIVE

To investigate the relationship between sleep problems and development in preschool children with suspected developmental delay.

METHODS

A total of 192 preschool children (mean age 4 years; 131 males, 61 females) were recruited from the Child Development Clinic, including 98 preterm children and 94 age- and sex-matched full-term children. All participants underwent evaluation of gross motor, fine motor and speech performance. All parents of all participants completed the Children's Sleep Habits Questionnaire (CSHQ). Some of the participants also underwent psychological evaluation. Correlation analysis and community network analysis were used to investigate the interactions.

RESULTS

The developmental status was: 75.5% developmental delay, 19.3% borderline development, and 5.2% normal development. Eighty-nine percent of the subjects had abnormal CSHQ scores. Age, gestational age, speech development, cognitive development, and socio-emotional development were significantly correlated with the CSHQ. Significant interactions between sleep problems and development were noted mostly in the preterm group.

CONCLUSION

High prevalence of sleep disturbances in children at the Child Development Center was noted and associated with multiple factors. Therefore, during the multidisciplinary evaluation of children with possible developmental delay, inquiring about their sleep quality and habits is strongly recommended. Mitigating sleep problems enhances the efficacy of early intervention programs.

Disturbed sleep in children born extremely preterm is associated with behavioural and emotional symptoms

AIM

To determine whether children born extremely preterm are at increased risk for sleep disturbances and to explore relationships between extremely preterm birth, sleep and attention-deficit/hyperactivity disorder (ADHD) symptoms and emotional symptoms.

METHOD

EPICure2 cohort study. Parents of 165 children born ≤26 weeks' gestation (53% male) and 121 children born at term (43% male) completed the Children's Sleep Habits Questionnaire, sleep disordered breathing subscale of the Pediatric Sleep Questionnaire, the emotional problems scale of the Strengths and Difficulties Questionnaire and the ADHD Rating Scale-5 at 11 years of age.

RESULTS

Extremely preterm children had greater habitual snoring (adjusted odds ratio 6.8; 95% confidence interval 2.3, 20.3), less frequently fell asleep within 20 minutes (Cohen's d 0.33), higher night wakings (d 0.44) and daytime sleepiness scores (d 0.40) than term-born children; there was no between-group difference in sleep duration scores. Among children without severe disability, night wakings scores partially mediated the relationship between preterm birth and inattention (additional 5% of variance explained), hyperactivity/impulsivity (13%) and emotional problems (9%). Snoring partially mediated the relationship between preterm birth, hyperactivity/impulsivity and inattention (additional 1-5% of variance).

CONCLUSION

Children born extremely preterm are at increased risk of disturbed sleep compared to term-born children. As night wakings partially mediated the relationship between preterm birth and ADHD symptoms and emotional problems, reducing sleep disturbance may improve sleep and reduce attention and emotional problems in this population.

Perinatal antecedents of sleep disturbances in schoolchildren

STUDY OBJECTIVES

Prematurity has been associated with an increased risk for sleep apnea. However, sleep disturbances in children born preterm have not been extensively investigated. Considering that determinants of sleep may originate early in life, the potential impact of prematurity on sleep disturbances later in life could be important. To establish the role of prematurity on sleep disturbances in a cohort of schoolchildren that were born preterm and compare them with healthy controls.

METHODS

A cohort of 147 schoolchildren, 45 born at term (≥37 weeks) and 102 very preterm (<32 weeks), was recruited and evaluated at school age (5-9 years). The Pediatric Sleep Questionnaire (PSQ) and the Sleep Disturbance Scale for Children (SDSC) were used to assess sleep disturbances in different domains.

RESULTS

PSQ score was significantly higher in former preterm children (0.26 ± 0.18 vs. 0.18 ± 0.14 in controls; p = 0.004), and SDSC total score was also significantly different among groups (21.7 ± 11.6 vs. 14.1 ± 12.6; p < 0.001). Regression models showed significant mean differences in PSQ score, total SDSC score, and two SDSC subscale scores (i.e. sleep-wake transition disorders, sleep-breathing disorders, and sleep hyperhidrosis) even after adjustment for confounders. Maternal age and type of delivery were not significantly associated with total PSQ scores.

CONCLUSIONS

Sleep disturbances may originate early in life since children born preterm exhibit an increased risk for developing long-term sleep problems. These findings may have important implications for management of preterm children and for implementation of early interventions focused on optimizing sleep habits.

Sleep patterns, problems, and ecology in young children born preterm and full-term and their mothers

BACKGROUND

Previous studies of sleep patterns and problems in preterm infants compared to full-term infants have yielded mixed results, with little known about sleep ecology. The aims of this study were to compare sleep patterns, sleep problems, and sleep ecology across developmental stages (birth to 36 months) in preterm (3 or more weeks early) infants and toddlers to those born full-term, in addition to their mothers' sleep.

METHODS

Mothers of 834 young children in Brazil (ages 0-35.9 months), half preterm and half full-term (matched for sex and chronological age), completed the Brief Infant Sleep Questionnaire and the Pittsburgh Sleep Quality Index.

RESULTS

Across the entire sample, preterm and full-term infants were similar for most sleep parameters, including sleep onset latency, number and duration of night awakenings, and sleep duration, as well as sleep ecology parameters, including falling asleep independently and sleep location. However, preterm infants were more likely to be held to initiate sleep, given a bottle to resume sleep after waking, and less likely to be breastfed to resume sleep after waking. Mothers of preterm infants, however, were more likely to report a parent-perceived sleep problem, although maternal-perceived confidence in managing child sleep and bedtime difficulty were similar. Finally, maternal sleep parameters were similar between groups.

CONCLUSIONS

Overall, these results indicate that sleep patterns, sleep problems, and sleep ecology among preterm infants and toddlers and their mothers are largely similar to those of full-term infants and toddlers and their mothers, even within the first few months.

The relationship between preterm birth and sleep in children at school age: A systematic review

Premature birth (before 37 weeks of gestation) has been linked to a variety of adverse neurological outcomes. Sleep problems are associated with decreased neurocognitive functioning, which is especially common in children born preterm. The exact relationship between prematurity and sleep at school age is unknown. A systematic review is performed with the aim to assess the relationship between prematurity and sleep at school age (5th to 18th year of life), in comparison to sleep of their peers born full-term. Of 347 possibly eligible studies, nine were included. The overall conclusion is that prematurity is associated with earlier bedtimes and a lower sleep quality, in particular more nocturnal awakenings and more non-rapid eye movement stage 2 sleep. Interpretations and limitations of the review are discussed. Moreover, suggestions for future research are brought forward, including the need for a systematic approach with consistent outcome measures in this field of research. A better understanding of the mechanisms that influence sleep in the vulnerable group of children born preterm could help optimize these children's behavioral and intellectual development.

Chronotype in very low birth weight adults - a sibling study

Chronotype is the temporal preference for activity and sleep during the 24 h day and is linked to mental and physical health, quality of life, and mortality. Later chronotypes, so-called "night owls", consistently display poorer health outcomes than "larks". Previous studies have suggested that preterm birth (<37 weeks of gestation) is associated with an earlier chronotype in children, adolescents, and young adults, but studies beyond this age are absent. Our aim was to determine if adults born preterm at very low birth weight (VLBW, ≤1500 g) display different chronotypes than their siblings. We studied VLBW adults, aged 29.9 years (SD 2.8), matched with same-sex term-born siblings as controls. A total of 123 participants, consisting of 53 sibling pairs and 17 unmatched participants, provided actigraphy-derived data on the timing, duration, and quality of sleep from 1640 nights (mean 13.3 per participant, SD 2.7). Mixed effects models provided estimates and significance tests. Compared to their siblings, VLBW adults displayed 27 min earlier sleep midpoint during free days (95% CI: 3 to 51 min, p =.029). This was also reflected in the timing of falling asleep, waking up, and sleep-debt corrected sleep midpoint. The findings were emphasized in VLBW participants born small for gestational age. VLBW adults displayed an earlier chronotype than their siblings still at age 30, which suggests that the earlier chronotype is an enduring individual trait not explained by shared family factors. This preference could provide protection from risks associated with preterm birth.

ABBREVIATIONS

AGA: Appropriate for gestational age; ELBW: Extremely low birth weight, ≤ 1000 grams; FMBR: Finnish Medical Birth Registry; HeSVA: Helsinki Study of Very low birth weight Adults; MSFsc: Midsleep on free days, corrected for sleep debt; SGA: Small for gestational age, ≤ -2 SD; VLBW: Very low birth weight, ≤ 1500 grams; WASO: Wake after sleep onset.

Impact of prematurity on neurodevelopment

The consequences of prematurity on brain functional development are numerous and diverse, and impact all brain functions at different levels. Prematurity occurs between 22 and 36 weeks of gestation. This period is marked by extreme dynamics in the physiologic maturation, structural, and functional processes. These different processes appear sequentially or simultaneously. They are dependent on genetic and/or environmental factors. Disturbance of these processes or of the fine-tuning between them, when caring for premature children, is likely to induce disturbances in the structural and functional development of the immature neural networks. These will appear as impairments in learning skills progress and are likely to have a lasting impact on the development of children born prematurely. The level of severity depends on the initial alteration, whether structural or functional. In this chapter, after having briefly reviewed the neurodevelopmental, structural, and functional processes, we describe, in a nonexhaustive manner, the impact of prematurity on the different brain, motor, sensory, and cognitive functions.

Docosahexaenoic Acid and Arachidonic Acid Supplementation and Sleep in Toddlers Born Preterm: Secondary Analysis of a Randomized Clinical Trial

STUDY OBJECTIVES

This secondary analysis characterized sleep patterns for toddlers born preterm and tested effects of docosahexaenoic acid (DHA)+ arachidonic acid (AA) supplementation on children's caregiver-reported sleep. Exploratory analyses tested whether child sex, birth weight, and caregiver depressive symptomatology were moderators of the treatment effect.

METHODS

Omega Tots was a single-site 180-day randomized (1:1), double-blinded, placebo-controlled trial. Children (n = 377) were age 10 to 16 months at enrollment, born at less than 35 weeks' gestation, assigned to 180 days of daily 200 mg DHA + 200 mg AA supplementation or placebo (400 mg corn oil), and followed after the trial ended to age 26 to 32 months. Caregivers completed a sociodemographic profile and questionnaires about their depressive symptomatology (Center for Epidemiologic Studies Depression Scale) and the child's sleep (Brief Infant Sleep Questionnaire). Analyses compared changes in sleep between the DHA+AA and placebo groups, controlling for baseline scores. Exploratory post hoc subgroup analyses were conducted.

RESULTS

Eighty-one percent (ntx = 156; nplacebo = 150) of children had 180-day trial outcome data; 68% (ntx = 134; nplacebo = 122) had postintervention outcome data. Differences in change between the DHA+AA and placebo groups after 180 days of supplementation were not statistically significant for the entire cohort. Male children (difference in nocturnal sleep change = 0.44, effect size = 0.26, P = .04; sleep problems odds ratio = 0.36, 95% confidence interval = 0.15, 0.82) and children of depressed caregivers (difference in nocturnal sleep change = 1.07, effect size = 0.65, P = .006; difference in total sleep change = 1.10, effect size = 0.50, P = .04) assigned to the treatment group showed improvements in sleep, compared to placebo.

CONCLUSIONS

Although there is no evidence of an overall effect of DHA+AA supplementation on child sleep, exploratory post hoc analyses identified important subgroups of children born preterm who may benefit. Future research including larger samples is warranted.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Identifier: NCT01576783.

CITATION

Boone KM, Rausch J, Pelak G, Li R, Turner AN, Klebanoff MA, Keim SA. Docosahexaenoic acid and arachidonic acid supplementation and sleep in toddlers born preterm: secondary analysis of a randomized clinical trial. J Clin Sleep Med. 2019;15(9):1197-1208.

Sleep and prematurity: sleep outcomes in preterm children and influencing factors

BACKGROUND

Sleep undergoes changes from birth to adulthood, while sleep disorders are associated with various cognitive deficiencies in childhood. In parallel, prematurity is known to predispose to poor neurodevelopmental outcomes. Our aim is to provide literature data about factors influencing sleep in the premature infants and sleep outcomes in this population.

METHODS

A systematic review was conducted using a variety of health-related databases. Original research papers were considered and no year-of-publication restriction was placed.

RESULTS

In total, 22 articles fulfilled our selection criteria. Available studies present remarkable heterogeneity in terms of methodological design. Compared to full term, premature infants exhibit significant differences in sleep structure, which mainly include differences in electroencephalographic spectral values, in total sleep time and in arousal threshold. Furthermore, prematurity seems to be a risk factor of sleep breathing disorders in childhood and adolescence. Data about the effect of methylxanthines and the environment of neonatal intensive care unit is controversial. With regard to the impact of prematurity-related sleep disorders on future neurodevelopment, available research papers are generally few.

CONCLUSIONS

The alterations in sleep patterns are an outcome of prematurity (immaturity of nervous system) as well as of postnatal factors and comorbidities. Sleep problems in this population of infants seems to be a missing piece of the puzzle of impaired neurodevelopment. Future studies should focus on interventions to improve sleep hygiene and limit neurodevelopmental problems.

Gestational age at birth and sleep duration in early childhood in three population-based cohorts

Background

Both preterm and post-term births have been associated with neonatal morbidity and mortality, including adverse impact on neurodevelopment. Important neural maturational processes take place during sleep in newborns, but findings on gestational duration and sleep in early childhood are contradictory and often derive from small clinical samples. We studied the association of gestational age at birth with sleep duration in early childhood in three population-based cohorts.

Methods

Gestational age at birth and sleep duration were assessed in three population-based cohort studies in The Netherlands (n = 6471), Singapore (n = 862), and Canada (n = 583). Gestational age at birth was assessed using ultrasound in pregnancy in combination with date of birth, and caregivers repeatedly reported on child sleep duration at three, six, 24, and 36 months of age. Generalized estimating equations were used, which were adjusted for confounders, and findings were pooled in a meta-analysis.

Results

Children born preterm (<37 weeks of gestation) showed longer sleep duration than children born at term; and children born post-term (≥42 weeks of gestation) showed shorter sleep duration. The meta-analysis indicated a small negative effect of gestational age on child sleep duration (effect size −0.11), when assessed in children born at term only.

Conclusion

In early childhood, children with a lower gestational age have a longer sleep duration, even when they are born at term (37–42 weeks of gestation). These subtle yet consistent findings point to the importance of maturational processes during sleep, not only in premature children but also in children born at term after shorter gestational duration.

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Children born after shorter gestational duration sleep longer than their term born peers.

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Lower gestational age is linked to longer sleep duration in three cohorts, even in term born children (37-42 weeks gestation).

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The association between gestational age and sleep duration is most prominent in the first year of life.

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Our subtle yet consistent findings point to the importance of maturational processes during sleep.

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Maturational processes underlying the interplay between gestational age and sleep duration should be investigated.

Sleep Duration and Nocturnal Awakenings in Infants Born with Gestational Risk

OBJECTIVE

Infants born with gestation-related risks (low birth weight (LBW), small for gestational age (SGA), and prematurely born infants) are faced with a cascade of developmental issues. The aim of this study was to investigate whether infants with gestation-related risks have different patterns of parent-reported sleep duration and nocturnal awakenings than children without these risk factors.

METHODS

Information on sleep duration and nocturnal awakenings was obtained by parental report at age 6 and 18 months in the Norwegian Mother and Child Cohort Study, which is a population-based longitudinal pregnancy cohort study conducted at the Norwegian Institute of Public Health. Birth weight and gestational age were obtained from the Medical Birth Registry of Norway. Outcomes were related to birth weight, prematurity, and to being born SGA.

RESULTS

A total of 75,531 mother-child dyads were included. Compared with children without gestational risks, children born SGA and with LBW had shorter sleep duration, whereas children born prematurely had longer sleep duration at both time points. The infants born SGA and with LBW, but not the prematurely born children, had fewer nocturnal awakenings at 6 months, but all had more awakenings at 18 months.

CONCLUSION

Infants with gestation-related risks show distinct sleep patterns. We suggest that sleep assessment is included in the follow-up of high-risk infants. Future studies are needed to investigate the predictive value and functional importance of the sleep patterns for infants with gestation-related risks.

Sleep problems, behavioural problems and respiratory health in children born extremely preterm: a parental questionnaire study

OBJECTIVE

To explore whether children born extremely preterm (EPT) with different types of sleep problems had more behavioural and respiratory health problems than EPT children without sleep problems.

DESIGN

Prospective, nationwide, questionnaire-based study. At 11 years of age, parents reported on four current sleep problems: difficulty falling asleep or frequent awakenings, snoring, daytime sleepiness and not recommended sleep duration (<9 hours). Behavioural problems were assessed by parents and teachers with the Strengths and Difficulties Questionnaire (SDQ). Parents assessed respiratory symptoms with the International Study of Asthma and Allergies in Childhood questionnaire and described use of asthma medication.

SETTING

Norway.

PATIENTS

EPT children.

MAIN OUTCOME MEASURES

Specified sleep problems, behavioural problems and respiratory health.

RESULTS

Data were obtained from 216 of 372 (58 %) of eligible children. All four specified sleep problems were associated with significantly higher parent-reported SDQ total-score (OR 1.1 for all), and except for not recommended sleep duration, also with higher teacher-reported SDQ total-score (OR 1.1 for all). Daytime sleepiness was strongly associated with wheezing last 12 months (OR 3.4), disturbed sleep due to wheezing (OR 3.9), wheeze during or after exercise (OR 2.9), use of inhaled corticosteroids or oral leukotriene modifiers (OR 3.4) and use of bronchodilators (OR 3.9). Snoring was associated with wheezing during or after exercise (OR 2.8) and current asthma (OR 4.2).

CONCLUSION

EPT children with different types of sleep problems had more behavioural and respiratory health problems than EPT children without sleep problems.

Sleep and its relationship to health in parents of preterm infants: a scoping review

BACKGROUND

Sleep is essential for human health and functioning. Parents of preterm infants are susceptible to sleep disturbances because of stress related to the preterm birth. Poor sleep has the potential to affect parental health and well-being. The aim of this study was to identify and map evidence on sleep and its relationship to health in parents of preterm infants. No review has summarized the evidence on this topic.

METHODS

A scoping review was conducted. Seven health and medical electronic research databases were searched for relevant quantitative and qualitative primary studies, including grey literature. The search was performed March 2-7, 2017.

RESULTS

Ten American studies and one Australian study were included in the review. Most research was quantitative and focused on maternal sleep and mental health within the first two weeks after the childbirth. Both objective and subjective sleep measures were used to study sleep at the hospital; actigraphs were not used after discharge. Maternal sleep was poor early postpartum, and this was associated with negative health outcomes. Two cohort studies compared sleep in mothers of preterm and term infants, but the results were conflicting. In one qualitative study, fathers described their inability to catch up on sleep after homecoming with a preterm baby.

CONCLUSIONS

Quantitative studies reporting on maternal sleep early postpartum was most frequently occurring in the results. Qualitative research on the topic was identified as a knowledge gap. More cultural and geographical breadth, including research on fathers' sleep, is recommended in future research.

Waking up too early - the consequences of preterm birth on sleep development

Good quality sleep of sufficient duration is vital for optimal physiological function and our health. Sleep deprivation is associated with impaired neurocognitive function and emotional control, and increases the risk for cardiometabolic diseases, obesity and cancer. Sleep develops during fetal life with the emergence of a recognisable pattern of sleep states in the preterm fetus associated with the development, maturation and connectivity within neural networks in the brain. Despite the physiological importance of sleep, surprisingly little is known about how sleep develops in individuals born preterm. Globally, an estimated 15 million babies are born preterm (<37 weeks gestation) each year, and these babies are at significant risk of neural injury and impaired brain development. This review discusses how sleep develops during fetal and neonatal life, how preterm birth impacts on sleep development to adulthood, and the factors which may contribute to impaired brain and sleep development, leading to altered neurocognitive, behavioural and motor capabilities in the infant and child. Going forward, the challenge is to identify specific risk factors for impaired sleep development in preterm babies to allow for the design of interventions that will improve the quality and quantity of sleep throughout life.

Prenatal and Neonatal Factors Predicting Sleep Problems in Children Born Extremely Preterm or With Extremely Low Birthweight

Objective: Prematurely born children have been reported to have more sleep problems throughout childhood than children born at term. The aim of this study was to explore if prenatal or neonatal factors can predict sleep problems at age 11 years in children born extremely preterm (EPT). Method: A prospective observational study of all infants who were born EPT in Norway in 1999 and 2000. Prenatal and neonatal data were collected by all Norwegian obstetric and pediatric departments. Parental questionnaire mapped sleep problems and sleep habits at the age of 11 years. Results: Of the 372 eligible children, 221 participated. Of those, 28.1% snored, 27.5% had difficulty falling asleep or frequent awakenings and 17.2% suffered from daytime sleepiness. The mean sleep duration was 9.4 h (range 4.3-11.0 h). Smoking in pregnancy predicted snoring (odds ratio 4.3). Neonatal cerebral hemorrhage and being born small for gestational age predicted difficulty falling asleep or frequent awakenings (odds ratio 2.2 and 2.3). Other morbidities during pregnancy or the newborn period, gestational age or the burden of treatment in the neonatal intensive care unit did not predict sleep problems. None of the studied prenatal or neonatal factors predicted daytime sleepiness or sleep duration <9 h. Conclusion: Of numerous prenatal and neonatal factors, only smoking during pregnancy, being born small for gestational age and cerebral hemorrhage predicted sleep problems at 11 years of age among these children born EPT.