Concordance between subjective and objective measures of infant sleep varies by age and maternal mood: Implications for studies of sleep and cognitive development

A longitudinal study of infant 24-hour sleep: comparisons of sleep diary and accelerometer with different algorithms

STUDY OBJECTIVES

To longitudinally compare sleep/wake identification and sleep parameter estimation from sleep diaries to accelerometers using different algorithms and epoch lengths in infants.

METHODS

Mothers and other caregivers from the Nurture study (southeastern United States, 2013-2018) reported infants' 24-hour sleep in sleep diaries for 4 continuous days, while infants concurrently wore accelerometers on the left ankle at 3, 6, 9, and 12 months of age. We applied the Sadeh, Sadeh Infant, Cole, and Count-scaled algorithm to accelerometer data at 15 and 60 seconds epochs. For sleep/wake identification, we assessed agreement by calculating epoch-by-epoch percent agreement and kappas. We derived sleep parameters from sleep diaries and accelerometers separately and evaluated agreement using Bland-Altman plots. We estimated longitudinal trajectories of sleep parameters using marginal linear and Poisson regressions with generalized estimation equation estimation.

RESULTS

Among the 477 infants, 66.2% were black and 49.5% were female. Agreement for sleep/wake identification varied by epoch length and algorithm. Relative to sleep diaries, we observed similar nighttime sleep offset, onset, and total nighttime sleep duration from accelerometers regardless of algorithm and epoch length. However, accelerometers consistently estimated about 1 less nap per day using the 15 seconds epoch, 70 and 50 minutes' shorter nap duration per day using the 15 and 60 seconds epoch, respectively; but accelerometers estimated over 3 times more wake after nighttime sleep onset (WASO) per night. Some consistent sleep parameter trajectories from 3 to 12 months from accelerometers and sleep diaries included fewer naps and WASOs, shorter total daytime sleep, longer total nighttime sleep, and higher nighttime sleep efficiency.

CONCLUSIONS

Although there is no perfect measure of sleep in infancy, our findings suggest that a combination of accelerometer and diary may be needed to adequately measure infant sleep.

Infant sleep predicts trajectories of social attention and later autism traits

BACKGROUND

Children with neurodevelopmental disorders including autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) often experience sleep disturbances, but little is known about when these sleep differences emerge and how they relate to later development.

METHODS

We used a prospective longitudinal design in infants with a family history of ASD and/or ADHD to examine infant sleep and its relation to trajectories of attention and later neurodevelopmental disorders. We formed factors of Day and Night Sleep from parent-reported measures (including day/night sleep duration, number of naps in the day, frequency of night awakenings and sleep onset problems). We examined sleep in 164 infants at 5-, 10- and 14-months with/without a first-degree relative with ASD and/or ADHD who underwent a consensus clinical assessment for ASD at age 3.

RESULTS

By 14-months, infants with a first-degree relative with ASD (but not ADHD) showed lower Night Sleep scores than infants with no family history of ASD; lower Night Sleep scores in infancy were also associated with a later ASD diagnosis, decreased cognitive ability, increased ASD symptomatology at 3-years, and developing social attention (e.g., looking to faces). We found no such effects with Day Sleep.

CONCLUSIONS

Sleep disturbances may be apparent at night from 14-months in infants with a family history of ASD and also those with later ASD, but were not associated with a family history of ADHD. Infant sleep disturbances were also linked to later dimensional variation in cognitive and social skills across the cohort. Night Sleep and Social Attention were interrelated over the first 2 years of life, suggesting that this may be one mechanism through which sleep quality influences neurodevelopment. Interventions targeted towards supporting families with their infant's sleep problems may be useful in this population.

Developing customized NIRS-EEG for infant sleep research: methodological considerations

Significance

Studies using simultaneous functional near-infrared spectroscopy (fNIRS)-electroencephalography (EEG) during natural sleep in infancy are rare. Developments for combined fNIRS-EEG for sleep research that ensure optimal comfort as well as good coupling and data quality are needed.

Aim

We describe the steps toward developing a comfortable, wearable NIRS-EEG headgear adapted specifically for sleeping infants ages 5 to 9 months and present the experimental procedures and data quality to conduct infant sleep research using combined fNIRS-EEG.

Approach

N = 49 5- to 9-month-old infants participated. In phase 1, N = 26 (10 = slept) participated using the non-wearable version of the NIRS-EEG headgear with 13-channel-wearable EEG and 39-channel fiber-based NIRS. In phase 2, N = 23 infants (21 = slept) participated with the wireless version of the headgear with 20-channel-wearable EEG and 47-channel wearable NIRS. We used QT-NIRS to assess the NIRS data quality based on the good time window percentage, included channels, nap duration, and valid EEG percentage.

Results

The infant nap rate during phase 1 was ∼ 40 % (45% valid EEG data) and increased to 90% during phase 2 (100% valid EEG data). Infants slept significantly longer with the wearable system than the non-wearable system. However, there were more included good channels based on QT-NIRS in study phase 1 (61%) than phase 2 (50%), though this difference was not statistically significant.

Conclusions

We demonstrated the usability of an integrated NIRS-EEG headgear during natural infant sleep with both non-wearable and wearable NIRS systems. The wearable NIRS-EEG headgear represents a good compromise between data quality, opportunities of applications (home visits and toddlers), and experiment success (infants' comfort, longer sleep duration, and opportunities for caregiver-child interaction).

Sleep habits and sleep disorders in Italian children and adolescents: a cross-sectional survey

STUDY OBJECTIVES

The aim was to describe sleep habits and epidemiology of the most common sleep disorders in Italian children and adolescents.

METHODS

This was a cross-sectional study in which parents of typically developing children and adolescents (1-18 years) completed an online survey available in Italy, gathering retrospective information focusing on sleep habits and disorders.

RESULTS

Respondents were 4,321 typically developing individuals (48.6% females). Most of our sample did not meet the age-specific National Sleep Foundation recommendations for total sleep duration (31.9% of toddlers, 71.5% of preschoolers, 61.6% of school-age children, and 41.3% of adolescents). Napping was described in 92.6% of toddlers and in 35.2% of preschoolers. Regarding geographical differences, children and adolescents of northern Italy showed more frequent earlier bedtimes and rise times than their peers of central and southern Italy. The most frequently reported sleep disorder in our sample was restless sleep (35.6%), followed by difficulties falling asleep (16.8%), > 2 night awakenings (9.9%), and bruxism (9.6%). Data also suggest that longer screen time is associated with later bedtimes on weekdays in all age groups.

CONCLUSIONS

The current study shows that Italian children are at risk of sleep disorders, particularly insufficient sleep, restless sleep, and difficulty falling asleep. The study also provides normative sleep data by age group in a large cohort of typically developing Italian children, emphasizing the importance of the developmentally, ecologically, and culturally based evaluation of sleep habits and disorders.

CITATION

Breda M, Belli A, Esposito D, et al. Sleep habits and sleep disorders in Italian children and adolescents: a cross-sectional survey. J Clin Sleep Med. 2023;19(4):659-672.

Relationships between postpartum depression, sleep, and infant feeding in the early postpartum: An exploratory analysis

Introduction

The study objectives were to determine the relationships between postpartum depression and maternal and infant sleep parameters and to examine the impact of infant feeding method on infant and maternal sleep and postpartum depression symptomatology.

Methods

Participants were 61 new mothers aged 18 to 45 years old, and their full-term, normal birth-weight, singleton infants. Participants were recruited from a large teaching hospital in northeast England. Data collection took place in participants' homes. The study used a prospective longitudinal design, with data collected at six, 12 and 18 weeks postpartum. We collected data on total sleep time, longest sleep period, wake after sleep onset, and night waking for mothers and infants objectively from actigraphic records and subjectively from maternal sleep logs. Participants reported on sleep disturbances using the General Sleep Disturbances Scale, on maternal sleepiness, and on depression symptomatology using the Edinburgh Postnatal Depression Scale.

Results

Scores on the Edinburgh Postnatal Depression Scale and General Sleep Disturbances Scale were consistently correlated with each other (6 weeks r = 0.452, p < 0.01; 12 weeks r = 0.317, p < 0.05; 18 weeks r = 0.493, p < 0.01), and did not correlate with objective measures or subjective reports of maternal or infant sleep. Edinburgh Postnatal Depression Scale scores at six, 12 and 18 weeks were predicted by General Sleep Disturbances Scale, prior Edinburgh Postnatal Depression Scale score, or both, but not by sleep parameters. With regard to infant feeding method, EPDS score was not higher among exclusively breastfeeding than among exclusively formula-feeding participants at any time point (6 weeks  t = 0.306, p = 0.762; 12 weeks  t = 0.343, p = 0.733; 18 weeks  t = 0.426; p = 0.673). Different pathways emerged to predict Edinburgh Postnatal Depression Scale score for exclusively breastfeeding and exclusively formula-feeding women.

Discussion

Postpartum depression may be associated with disturbed sleep due to negative perception of sleep among depressed women, rather than disrupted sleep causing postpartum depression. With regard to infant feeding method, exclusively breastfeeding women are not more likely to suffer from postpartum depression, and different pathways may predict development of postpartum depression symptoms in exclusively breastfeeding and exclusively formula feeding women.

Habitual night waking associates with dynamics of waking cortical theta power in infancy

The implications of the substantial individual differences in infant sleep for early brain development remain unclear. Here, we examined whether night sleep quality relates to daytime brain activity, operationalized through measures of EEG theta power and its dynamic modulation, which have been previously linked to later cognitive development. For this longitudinal study, 76 typically developing infants were studied (age: 4-14 months, 166 individual study visits) over the course of 6 months with one, two, three, or four lab visits. Habitual sleep was measured with a 7-day sleep diary and actigraphy, and the Brief Infant Sleep Questionnaire. Twenty-channel EEG was recorded while infants watched multiple rounds of videos of women singing nursery rhymes; oscillatory power in the theta band was extracted. Key metrics were average theta across stimuli and the slope of change in theta within the first novel movie. Both objective and subjective sleep assessment methods showed a relationship between more night waking and higher overall theta power and reduced dynamic modulation of theta over the course of the novel video stimuli. These results may indicate altered learning and consolidation in infants with more disrupted night sleep, which may have implications for cognitive development.

Links between Daytime Napping, Night-Time Sleep Quality and Infant Attention: An Eye-Tracking, Actigraphy and Parent-Report Study

The current study explored the potential influence of infant sleep, measured by parental report and actigraphy, and family functioning on attention development using eye tracking. The use of actigraphy in parallel with parental report, has the advantage of measuring participant’s sleep throughout the night without parental observation and the ability to objectively assess sleep quality. An eye-tracking version of the Gap-Overlap task was used to measure visual attention. Questionnaires and behavioural assessment were used to assess family function, and general cognitive development. Fifty infants (Mean age = 13.44 months, SD = 3.10) participated in the study, 23 of which had full final datasets. Results show that daytime sleep duration, as measured by parental report, and proportion of light sleep at night, as measured by actigraphy, are linked to visual attention. A higher proportion of light sleep, a marker of poorer sleep quality, and less daytime sleep were negatively linked with facilitation and disengagement on the Gap-Overlap task. Family functioning was not associated with attention. The results provide initial evidence that in addition to the amount of daytime sleep; quality of night-time sleep as measured by proportion of light sleep, is a potentially useful sleep variable which requires further focus in the study of attention development.