Finnish children who needed long-term home respiratory support had severe sleep-disordered breathing and complex medical backgrounds.

AIM: No studies have described long-term paediatric home respiratory support in Nordic countries. We examined the clinical characteristics and long-term outcomes of paediatric patients who received continuous positive airway pressure, non-invasive-positive-pressure ventilation and invasive ventilation from a multidisciplinary home respiratory support team. METHODS: Retrospective tertiary-level data were collected between 1 January 2010 and 31 December 2020 in Tampere University Hospital. These comprised patient demographics, treatment course and polysomnography-confirmed sleep-disordered breathing (SDB). RESULTS: There were 93 patients (63.4% boys). The median age at treatment initiation was 8.4 (range 0.11-16.9) years. The patients had: neuromuscular disease (16.1%), central nervous system disease (14.0%), developmental disabilities and congenital syndrome (29.0%), lung-airway conditions (11.8%), craniofacial syndrome (15.1%) and severe obesity (14.0%). More than two-thirds had severe SDB (66.7%) and the most common one was obstructive sleep apnoea in 66.7%. We found that 92.5% received long-term therapy for more than 3 months and the mean treatment duration was 3.3 ± 2.7 years. A non-invasive mask interface was used in 94.7% of cases and 5.3% needed tracheostomy ventilation. More than a quarter (26.7%) achieved disease resolution during the study period. CONCLUSION: Most children who needed long-term home respiratory support had complex conditions and severe, persistent SDB.

Genetic background to attention deficit and hyperactivity disorder and attention deficit and hyperactivity disorder symptoms at the age of 5 years: the role of sleep duration.

STUDY OBJECTIVES: We studied the associations between polygenic risk score (PRS) for attention deficit and hyperactivity disorder (ADHD) and (1) ADHD symptoms in 5-year-old children, (2) sleep duration throughout childhood, and (3) the interaction between PRS for ADHD and short sleep duration relative to ADHD symptoms at 5 years. METHODS: This study is based on the population-based CHILD-SLEEP birth cohort (N = 1420 children). PRS was used to quantitate the genetic risk for ADHD. Parent-reported ADHD symptoms at 5 years were obtained from 714 children, using the Strengths and Difficulties Questionnaire (SDQ) and the Five-to-Fifteen (FTF). Our primary outcomes were SDQ-hyperactivity and FTF-ADHD total scores. Parent-reported sleep duration was measured at 3, 8, 18, 24 months, and 5 years in the whole sample and actigraphy-based sleep duration at 2 and 24 months in a subsample. RESULTS: PRS for ADHD associated with SDQ-hyperactivity (ß = 0.214, p = .012) and FTF-ADHD total (ß = 0.639, p = .011), and FTF-inattention and hyperactivity subscale scores (ß = 0.315, p = .017 and ß = 0.324, p = .030), but not with sleep duration at any time point. Significant interactions were found between high PRS for ADHD and parent-reported short sleep throughout childhood in FTF-ADHD total score (F = 4.28, p = .039) and FTF-inattention subscale (F = 4.66, p = .031). We did not find any significant interaction between high PRS for ADHD and actigraphy-based short sleep. CONCLUSIONS: Parent-reported short sleep moderates the association between genetic risk of ADHD and ADHD symptoms in early childhood in the general population, so that children with short sleep, in combination with high genetic risk for ADHD, could be at highest risk for ADHD symptoms.

Sleep disturbances and depressive and anxiety symptoms during pregnancy: associations with delivery and newborn health.

BACKGROUND: Sleep disturbances and mood symptoms are common in late pregnancy; according to the literature, they can affect delivery and newborn outcomes. This study evaluated the effect of sleep and mood symptoms on delivery and newborn health, because there are insufficient and partly contradictory studies on the topic. METHODS: A cohort of 1414 mothers in their third trimester was enrolled in this prospective cross-sectional questionnaire study. Validated questionnaires were assessed for the measurement of sleep disturbances and depressive and anxiety symptoms. The data on delivery and newborn outcomes were obtained from hospital medical records. RESULTS: Sleep disturbances were very common. A higher insomnia score (ß = - 0.06, p = 0.047) and longer sleep need (ß = 0.07, p = 0.047) were related to delivery at a lower gestational age. In addition, a higher insomnia score (ß = - 28.30, p = 0.010) and lower general sleep quality (ß = - 62.15, p = 0.025) were associated with lower birth weight, but longer sleep duration and longer sleep need with a higher birth weight (ß = 28.06, p = 0.019; ß = 27.61, p = 0.028, respectively). However, the findings regarding birth weight lost their significance when the birth weight was standardized by gestational weeks. Concerning Apgar scores and umbilical artery pH, no associations were found. Snoring was associated with a shorter duration of the first phase of delivery (ß = - 78.71, p = 0.015) and total duration of delivery (ß = - 79.85, p = 0.016). Mothers with higher insomnia, depressive, or anxiety symptoms were more often treated with oxytocin (OR 1.54 95% CI 1.00-2.38, p = 0.049, OR 1.76, 95% CI 1.02-3.04, p = 0.049 and OR 1.91, CI 95% 1.28-2.84, p < 0.001, respectively) and those with higher depressive and anxiety symptoms were delivered more often with elective cesarean section (OR 4.67, 95% CI 2.04-12.68, p < 0.001 and OR 2.22, 95% CI 1.03-4.79, p = 0.042). CONCLUSIONS: Maternal sleep disturbances and mood symptoms during pregnancy are associated with delivery and newborn health. However, nearly, all the outcomes fell within a normal range, implying that the actual risks are low.

Paternal perinatal stress is associated with children's emotional problems at 2 years.

BACKGROUND: Paternal mental health in pregnancy and postpartum has been increasingly highlighted as important both in its own right, but also as crucial for the development of children. Rates of help-seeking among fathers is low, possibly due to conceptualising their own difficulties as stress rather than problems with mood. The relationship between paternal stress and child outcomes has not been investigated. METHODS: This study used data from the Finnish CHILD-SLEEP birth cohort. Data were available for 901 fathers and 939 mothers who completed questionnaires on demographics, stress, anxiety and depression at 32 weeks gestation, 3 months, 8 months and 24 months postpartum. Parental report of child emotional and behavioural problems was collected at 24 months. RESULTS: Around 7% of fathers experienced high stress (over 90% percentile) at each timepoint measured in the perinatal period, rising to 10% at 2 years postpartum. Paternal stress measured antenatally, at 3 and 24 months was associated with child total problems at 24 months, while paternal depression and anxiety were not related to child outcomes when in the same model. After adjusting for concurrent maternal depression, anxiety and stress, an association remained between paternal stress at each timepoint and child total problem scores at 24 months. The strongest association was with paternal stress at 3 months (OR 3.17; 95% CI 1.63-6.16). There were stronger relationships between paternal stress and boys' rather than girls' total problem scores, although the interactions were not statistically significant. CONCLUSIONS: Paternal stress is an important manifestation of perinatal distress and is related to child mental health, particularly when present in the early postpartum months. Paternal stress should therefore be assessed in the perinatal period, which presents opportunities for early intervention and prevention of difficulties for both father and child.

Season is related to the slow wave and sigma activity of infants and toddlers.

OBJECTIVE/BACKGROUND: Slow wave activity (SWA) and sigma frequency activity (SFA) are hallmarks of NREM sleep EEG and important indicators of neural plasticity, development of the central nervous system, and cognition. However, little is known about the factors that modulate these sleep EEG activities, especially in small children. PATIENTS/METHODS: We analyzed the power spectral densities of SWA (1-4 Hz) and SFA range (10-15 Hz) from six EEG derivations of 56 infants (8 months) and 60 toddlers (24 months) during their all-night sleep and during the first and the last half of night sleep. The spectral values were compared between the four seasons. RESULTS: In the spring group of infants, compared with the darker seasons, SFA was lower in the centro-occipital EEG derivations during both halves of the night. The SWA findings of the infants were restricted to the last half of the night (SWA2) and frontally, where SWA2 was higher during winter than spring. The toddlers presented less frontal SWA2 during winter compared with autumn. Both age groups showed a reduction in both SWA and SFA towards the last half of the night. CONCLUSIONS: The sleep EEG spectral power densities are more often associated with seasons in infants' SFA range. The results might stem from seasonally changing light exposure, but the exact mechanism warrants further study. Moreover, contrary to the adult-like increment of SFA, the SFA at both ages was lower at the last part of the night sleep. This suggests different regulation of spindle activity in infants and toddlers.

Finnish children who experienced narcolepsy after receiving the Pandemrix vaccine during the 2009-2010 H1N1 pandemic demonstrated high level of psychosocial problems.

AIM: We assessed psychosocial burdens in children who developed narcolepsy after receiving the Pandemrix H1N1 vaccine during the 2009-2010 pandemic. Parental quality of life was also assessed. METHODS: This multicentre study covered four of the five Finnish University Hospital Districts, which dealt with about 90% of the paediatric narcolepsy cases after the Pandemrix vaccination. The medical records of children diagnosed from 2010 to 2014 were reviewed. The questionnaires included the Youth Self-Report (YSR), Children's Depression Inventory (CDI), the Child Behaviour Checklist (CBCL) and questions on parental resources, stress and quality of life. RESULTS: We obtained the medical records of 94 children who were aged 5-17 years at the time of their narcolepsy diagnosis and questionnaire data for 73 of those children. Most children had strong narcolepsy symptoms, and 25% had CDI scores that suggested depression. In addition, 41% had total CBCL problem scores above the clinically significant limit and 48% were anxious, withdrawn and had somatic complaints. Sleep latency was weakly associated with the CBCL total problem score. Half of the children needed psychiatric interventions and parental stress was common. CONCLUSION: Depression and behavioural problems were common in children with narcolepsy after the Pandemrix vaccination and their parents frequently reported feeling stressed.

Signaled night awakening and its association with social information processing and socio-emotional development across the first two years.

STUDY OBJECTIVES: Night awakening is common in infancy, and some infants continue to have signaled night awakenings throughout early childhood. However, the influence of signaled night awakening on children's social development is less explored. In the present study, longitudinal associations between signaled night awakening, social information processing, and socio-emotional development were measured within the CHILD-SLEEP birth cohort in two groups formed based on parent-reported night awakenings. METHODS: At 8 months, there were 77 infants in the waking group (≥3 awakenings) and 69 infants in the nonwaking group (≤1 awakening). At 8 and 24 months, social information processing was measured as children's attention to neutral and emotional faces, and at 24 months, parent-reported socio-emotional behavior was measured with the Brief Infant-Toddler Social and Emotional Assessment (BITSEA) questionnaire. RESULTS: The two groups showed different patterns of attention to emotional faces. The waking group had a more pronounced attentional bias to fearful versus happy faces, whereas in the nonwaking group, attention to fearful and happy faces did not differ. In addition, at 24 months, the waking group had more dysregulation problems and lower social competence than the nonwaking group, but no clear differences in internalizing or externalizing problems were found. CONCLUSIONS: Our results contribute to the literature by showing that during the first 2 years of life, signaled night awakening is associated with social information processing and socio-emotional behavior.

Exposure to electronic media was negatively associated with speech and language development at 18 and 24 months.

AIM: This study evaluated early speech and language development at 18 and 24 months, and associated factors, based on parental reports. METHOD: We followed up the CHILD-SLEEP birth cohort of 1667 Finnish-speaking families, who were randomly recruited in 2011-2013 during routine visits to maternity clinics in the Pirkanmaa Hospital District of Finland. The women were approximately 32 weeks' pregnant at enrolment. Parents reported the size of their child's expressive vocabulary, word combinations, intelligibility, finger-pointing and adherence to instructions. A subsample was studied using the Expressive Language subscale of the Bayley Scales of Infant and Toddler Development, Third Edition. RESULTS: The children's vocabulary was smaller than previously reported. At 18 months of age, 68.8% of the 997 children had a vocabulary of 20 words or less and 35.7% used about five words at most. At 24 months, 32.4% of the 822 children had a vocabulary of 50 words or less and 18.4% used about 20 words at most. Longer child and parental exposure to electronic media was negatively associated with the size of the child's expressive vocabulary. CONCLUSION: Vocabulary size at 18 and 24 months was smaller than previously reported and negatively associated with exposure to electronic media.

Prevalence and evolution of snoring and the associated factors in two-year-old children.

OBJECTIVES: To evaluate the prevalence and persistence of snoring during the first two years of life in two Finnish birth cohorts and to assess the associated factors. STUDY DESIGN: The study population comprised 947 children from the CHILD-SLEEP (CS) and 1393 children from the FinnBrain (FB) birth cohorts. Questionnaires were provided to both parents when the child was 24 months of age. The questionnaire consisted of parts concerning the child's sleep and environmental factors. RESULTS: The combined prevalence of habitual snoring in the two birth cohorts at the age of 24 months was 2.3% (95% CI 1.5-3.1), which is markedly lower than reported previously. Children suffering from recurrent infections (CS odds ratio (OR) 3.9, 95% CI 1.2-12.5) or asthma (FB OR 4.3, 1.4-13.5) snored habitually more often. Both the mother's (CS OR 3.2, 1.2-9.0) and father's (CS OR 3.4, 1.4-8.0) snoring every night added to the risk of the child snoring. In the multivariate models, parental snoring (CS adjusted odds ratio (ORa) 2.8, 1.1-6.8), the mother's lower level of education (CS ORa 2.9, 1.2-7.5, FB ORa 2.1, 1.0-4.5), and the mother's lower monthly income (FB ORa 2.9, 1.3-6.3) associated with the child's habitual snoring. CONCLUSIONS: The prevalence of habitual snoring in two Finnish birth cohorts is lower than reported previously. The independent risk factors for habitual snoring at the age of two years were the parents' snoring and the mother's low income and low education.

High-dose electronic media use in five-year-olds and its association with their psychosocial symptoms: a cohort study.

OBJECTIVES: This study investigated the frequency of electronic media (e-media) usage by preschool children and the risks of high-dose e-media use on young children's psychosocial well-being. DESIGN: Longitudinal associations between e-media use at 18 months and psychosocial symptoms at 5 years of age were studied, as well as cross-sectional associations between e-media use and psychosocial symptoms at 5 years. SETTING: Between 2011 and 2017 in Finland. PARTICIPANTS: Children aged 5 years (n=699). PRIMARY AND SECONDARY OUTCOME MEASURES: Children's psychosocial symptoms were determined at the age of 5 years using the parent-reported questionnaires Five-to-Fifteen (FTF) and the Strengths and Difficulties Questionnaire (SDQ). RESULTS: Based on our results, 95% of the preschool children exceeded the daily recommended use of e-media set by health professionals. Our results indicate that increased screen time at 5 years of age is associated with a risk of multiple psychosocial symptoms (OR 1.53-2.18, 95% CI 1.05 to 3.34, p<0.05), while increased levels of e-media use at 18 months was only associated with FTF peer problems (OR 1.59, 95% CI 1.04 to 2.41, p=0.03). Moreover, high-dose use of electronic games at the age of 5 years seems to be associated with fewer risks for psychosocial well-being than programme viewing, as it was only associated with SDQ hyperactivity (OR 1.65, 95% CI 1.08 to 2.51, p=0.02). CONCLUSION: Increased screen time has multiple risks for children's psychosocial well-being. These risk factors seem to be significant in the long term, and are related to problems in children's socio-emotional development later on. Health professionals and paediatricians have an important role as communicators of the current research results on the safe usage time of e-media for families, and enhancing parents' skills as regulators of children's safe e-media use. More research is needed on the family conditions of high-dose e-media users.

The Effects of Genetic Background for Diurnal Preference on Sleep Development in Early Childhood.

PURPOSE: No previous research has examined the impact of the genetic background of diurnal preference on children´s sleep. Here, we examined the effects of genetic risk score for the liability of diurnal preference on sleep development in early childhood in two population-based cohorts from Finland. PARTICIPANTS AND METHODS: The primary sample (CHILD-SLEEP, CS) comprised 1420 infants (695 girls), and the replication sample (FinnBrain, FB; 962 girls) 2063 infants. Parent-reported sleep duration, sleep-onset latency and bedtime were assessed at three, eight, 18 and 24 months in CS, and at six, 12 and 24 months in FB. Actigraphy-based sleep latency and efficiency were measured in CS in 365 infants at eight months (168 girls), and in 197 infants at 24 months (82 girls). Mean standard scores for each sleep domain were calculated in both samples. Polygenic risk scores (PRS) were used to quantitate the genetic risk for eveningness (PRSBestFit) and morningness (PRS10kBest). RESULTS: PRSBestFit associated with longer sleep-onset latency and later bedtime, and PRS10kBest related to shorter sleep-onset latency in CS. The link between genetic risk for diurnal preference and sleep-onset latency was replicated in FB, and meta-analysis resulted in associations (P<0.0005) with both PRS-values (PRSBestFit: Z=3.55; and PRS10kBest: Z=-3.68). Finally, PRSBestFit was related to actigraphy-based lower sleep efficiency and longer sleep latency at eight months. CONCLUSION: Genetic liability to diurnal preference for eveningness relates to longer sleep-onset during the first two years of life, and to objectively measured lowered sleep efficiency. These findings enhance our understanding on the biological factors affecting sleep development, and contribute to clarify the physiological sleep architecture in early childhood.

Sleep Spindle Features and Neurobehavioral Performance in Healthy School-Aged Children.

PURPOSE: In adults, central fast-frequency sleep spindles are involved in learning and memory functions. The density of local spindles is higher than global spindles, emphasizing the importance of local plastic neural processes. In children, findings on the association of spindles with cognition are more variable. Hence, we aim to study whether the local spindles are also important for neurobehavioral performance in children. METHODS: We studied the correlations between local (occurring in only one channel: Fp1, Fp2, C3, or C4), bilateral, and diffuse (occurring in all four channels) spindles and neurobehavioral performance in 17 healthy children (median age 9.6 years). RESULTS: Local spindles were not as frequent as bilateral spindles (P-values < 0.05). Central spindle types had significant correlations with sensorimotor and language functions (e.g., the density of bilateral central spindles correlated positively with the Object Assembly in NEPSY, r = 0.490). Interestingly, frontopolar spindles correlated with behavior (e.g., the more bilateral the frontopolar spindles, the less hyperactive the children, r = -0.618). CONCLUSIONS: In children, the local spindles, but also more widespread central spindles, seem to be involved in the cognitive processes. Based on our findings, it is important that ageadjusted frequency limits are used in studies evaluating the frequencies of spindles in children.

Prenatal and Postnatal Predictive Factors for Children's Inattentive and Hyperactive Symptoms at 5 Years of Age: The Role of Early Family-related Factors.

We examined several parent-reported prenatal and postnatal factors as potential risk factors for attention-deficit and hyperactivity disorder (ADHD) symptomatology in 5-year-old children. Our study is based on the CHILD-SLEEP birth cohort. Several parental questionnaires were collected prenatally (32nd pregnancy week) and postnatally (i.e. child aged 3, 8, and 24 months and at 5 years). At 5 years of age, ADHD symptoms were assessed using questionnaires. Our main results showed that being a boy, parental depressive symptoms, more negative family atmosphere or a child's shorter sleep duration, and maternal authoritarian parenting style predicted inattentive/hyperactive symptoms. Maternal and paternal authoritative parenting style predicted less inattentive/hyperactive symptoms. Children with several risk factors together had the highest risk for inattentive/hyperactive symptoms. Our findings emphasise the need for early screening and treatment of parental mental health, and early evidence-based targeted parental support, to enable early intervention in those children at a risk of developing ADHD.

Snoring toddlers with and without obstructive sleep apnoea differed with regard to snoring time, adenoid size and mouth breathing.

AIM: The difficulty of assessing the likelihood of obstructive sleep apnoea (OSA) in children who snore without full-night polysomnography is widely recognised. Our aim was to identify features that were characteristic of two-year-old children with OSA and evaluate whether this information could be used to assess the likelihood of OSA. METHODS: The study was carried out as part of the Child-Sleep Project, a longitudinal birth cohort study of children born at Tampere University Hospital, Finland. This part of the study focused on the children in the cohort who snored and was carried out between 2013 and 2015. The primary outcomes were measured using parental questionnaires, polysomnography and clinical examinations. RESULTS: In total, 52 children participated at a mean age of 27 months (range 23-34). Of these, 32 (44% male) snorers and 20 (70% male) controls. The most significant findings were that children who had OSA demonstrated longer snoring time (P = .003), a greater tendency for mouth breathing (P = .007) and bigger adenoid size (P = .008) than snorers without OSA. CONCLUSION: Snoring time, adenoid tissue size and mouth breathing were important features that identified the likelihood of OSA in snoring toddlers.

Maternal stress or sleep during pregnancy are not reflected on telomere length of newborns.

Telomeres play an important role in maintaining chromosomal integrity. With each cell division, telomeres are shortened and leukocyte telomere length (LTL) has therefore been considered a marker for biological age. LTL is associated with various lifetime stressors and health-related outcomes. Transgenerational effects have been implicated in newborns, with maternal stress, depression, and anxiety predicting shorter telomere length at birth, possibly reflecting the intrauterine growth environment. Previous studies, with relatively small sample sizes, have reported an effect of maternal stress, BMI, and depression during pregnancy on the LTL of newborns. Here, we attempted to replicate previous findings on prenatal stress and newborn LTL in a sample of 1405 infants using a qPCR-based method. In addition, previous research has been expanded by studying the relationship between maternal sleep quality and LTL. Maternal prenatal stress, anxiety, depression, BMI, and self-reported sleep quality were evaluated with self-reported questionnaires. Despite sufficient power to detect similar or even considerably smaller effects than those previously reported in the literature, we were unable to replicate the previous correlation between maternal stress, anxiety, depression, or sleep with LTL. We discuss several possible reasons for the discrepancies between our findings and those previously described.

Sleep architecture is related to the season of PSG recording in 8-month-old infants.

To date, little is known about the impact of season on infant sleep. In higher latitudes, the duration of daily light time varies substantially between different seasons, and environmental light is one potential factor affecting sleep. In this cohort study, one-night polysomnography (PSG) was performed on 72 healthy 8-month-old infants in 2012 and 2013 to study the effect of season on the sleep architecture of young infants in Finland. The children were divided into four subgroups, according to the amount of light during their birth season and the amount of light during the season of the PSG recordings, corresponding to spring, summer, autumn, and winter. We found that the season of birth did not have an impact on the infants' sleep architecture at 8 months of age, but the season of the PSG recording did have an effect on several sleep variables. In the PSGs conducted during the spring, there was less N3 sleep and more N2 sleep than in the PSGs conducted during the autumn. In addition, there was more fragmented sleep during spring than autumn. According to our data, the season has an effect on the sleep architecture of young infants and should, therefore, be considered when evaluating the PSG findings of young infants. The exact mechanisms behind this novel finding remain unclear, however. The findings imply that infants` sleep is affected by the season or light environment, as is the case in adult sleep. Since potential explanatory factors, such as direct natural or artificial light exposure and the melatonin levels of the infants, were not controlled, more research is needed in the future to better understand this phenomenon.

Slow-wave activity and sigma activities are associated with psychomotor development at 8 months of age.

STUDY OBJECTIVES: The electrophysiological properties of non-rapid eye movement sleep (NREM) EEG are homeostatically modulated on global and local use-dependent levels. Furthermore, the local NREM quality reflects age-dependent brain maturation and individual, age-independent, and psychomotor potential. Cortical maturation and its electrophysiological marker, Slow-wave activity (SWA), as well as sleep spindles are known to change in topography and quality during the early years of life, but their associations with psychomotor development in infants are unknown. Therefore, we aimed to evaluate the local properties of SWA and spindles (sigma power) and ascertain whether they correlate with psychomotor development in 8-month-old infants. METHODS: Ambulatory polysomnographies were recorded in 56 infants at 8 months of age to calculate the local SWA and sigma powers. The associations between the SWA and sigma powers and psychomotor development (Bayley-III) were examined in 36 of these infants. RESULTS: In both hemispheres, the highest SWA and sigma powers were found occipitally and centrally, respectively, with higher powers in the right hemisphere than in the left. The Bayley-III correlated with local SWA and sigma powers: the occipital SWA and centro-occipital sigma correlated with cognitive scales, and the frontal and occipital SWA and centro-occipital sigma correlated with language and fine motor scales. Most of the correlations were unilateral. CONCLUSIONS: In 8-month-old infants, the NREM sleep quality shows local differences that are mostly attributable to the topical phase of brain maturation. The local NREM parameters correlate with psychomotor development.

Parent-reported early sleep problems and internalising, externalising and dysregulation symptoms in toddlers.

BACKGROUND: The concurrence of sleep and socio-emotional development in children is well accepted. However, the predictive role of sleep problems in infancy and the development of emotional and behavioural problems later in childhood remain still unclear. Therefore, in this study we examined the associations between sleep problems in early childhood and internalising, externalising and dysregulation symptoms in toddlers. METHODS: 1679 families entered the study during pregnancy and 936 children participated at 24 months. Parent-reported sleep duration, sleep-onset latency, night wakings, proportion of daytime sleep and bedtime at 3, 8, 18 and 24 months were assessed with two sleep questionnaires. Externalising, internalising and dysregulation problems at 24 months were examined with the Brief Infant-Toddler Social and Emotional Assessment. RESULTS: Short sleep duration at 3 and 8 months, more night wakings at 3, 8, 18 and 24 months and greater proportion of daytime sleep at 24 months were associated with internalising symptoms. Shorter sleep duration at 8, 18 and 24 months and longer sleep-onset latency and more night wakings at all time points, in addition to earlier bedtime at 8 months and greater proportion of daytime sleep at 24 months, were related to dysregulation. Finally, more night wakings at 3 and 24 months, and longer sleep-onset latency at 24 months were associated with externalising problems. CONCLUSION: Shorter sleep and poorer sleep quality in infancy were prospectively related to emotional and behavioural symptoms in toddlers, and these associations were strongest for internalising and dysregulation symptoms. This study contributes to the recent research on the role of early sleep problems in socio-emotional development, suggesting that shorter sleep duration, longer sleep-onset latency and higher waking frequency are related to internalising, externalising and dysregulation symptoms in toddlers, and thus it might be beneficial to provide early interventions for those infants reporting these sleep problems.

Normal sleep development in infants: findings from two large birth cohorts.

OBJECTIVE: Sleep difficulties are highly prevalent and often persistent in young children, but sometimes parents are worried about sleep symptoms that belong to the normative range rather than to actual disturbances. Therefore, the aim of this study was to describe the normative development of sleep at the ages of 3, 6, 8, 12, 18 and 24 months in healthy children. METHODS: The present study is based on two birth cohorts that comprise representative samples of families recruited systematically during pregnancy. In the CHILD-SLEEP cohort, the sample sizes were 1427 at three, 1301 at eight, 1163 at 18, and 950 at 24 months. In the Finnbrain cohort, the sample sizes were 2002 at six months and 1693 at 12 months. Healthy term-born children were eligible for this study. To assess the infants' sleep duration and sleep quality, the Brief Infant Sleep Questionnaire was used in both cohorts and additionally the Infant Sleep Questionnaire in the CHILD-SLEEP cohort. The distributions of the study variables were reported using standard parameters. RESULTS: We found that sleep quality is highly variable particularly during the first two years of life, but this variability decreased markedly towards the second year. First, sleep latency decreased by the age of six months, while night-time sleep began to consolidate during the second year. However, parent-reported sleeping problems were common during the entire study period. CONCLUSION: As many families struggle with infants' sleeping problems, the reference values reported in this article can be valuable tools in various clinical settings to define clinically significant deviances in the sleep development and to identify individuals benefitting from counselling and clinical interventions.

Maternal and paternal depressive symptoms and children's emotional problems at the age of 2 and 5 years: a longitudinal study.

BACKGROUND: Maternal and paternal depressive symptoms are related to children's emotional problems, but their combined effect remains unclear. Here, we constructed four parental longitudinal depressive symptom trajectory groups and studied their associations with children's emotional problems at the age of 2 and 5 years. METHODS: We did an assessment of maternal and paternal depressive symptoms (gestational week 32, as well as 3, 8 and 24 months postnatally) and children's emotional problems at ages two (N = 939) and five (N = 700) in the CHILD-SLEEP cohort. Three separate maternal and paternal depressive symptom trajectories based on latent profile analysis were combined to form four parental depressive symptom trajectory groups. We compared groups with a general linear model, with children's emotional (total, internalizing and externalizing) - problem scores serving as the dependent variables. RESULTS: At both ages, combined parental depressive symptom trajectories were associated with children's emotional problems: effect sizes were medium for total and small for other domains. According to post hoc comparisons, children whose mothers or both parents had persistent depressive symptoms had significantly more total, externalizing and internalizing problems than did children who had neither parent nor only the father showing depressive symptoms. A higher (and persistent) level of maternal depressive symptoms was related to a higher level of these children's emotional problems, a pattern not evident with paternal depressive symptoms. In all analyses, the interaction effect was nonsignificant between parental trajectories and child gender. CONCLUSIONS: Findings suggest that an absence of depressive symptoms in their fathers cannot compensate for the adverse effects of maternal depressive symptoms upon their children. Moreover, paternal depressive symptoms alone do not lead to increased risk for emotional problems in these 2- and 5-year-old children. In contrast, even subclinical levels of maternal depressive symptoms in late pregnancy are associated with increased risk for their children's experiencing internalizing and externalizing emotional problems.