Infant sleep behaviors relate to their later cognitive and language abilities and morning cortisol stress hormone levels

The role of sleep disturbances in associations between early life adversity and subsequent brain and language development during childhood

Sleep disturbances are posited to play a key role in the development of poor mental and physical health outcomes related to early life adversity (ELA), in part through effects on brain development. Language development is critically important for health and developmental outcomes across the lifespan, including academic achievement and emotion regulation. Yet, very little research has focused on the dynamic contributions of ELA, sleep, and brain development on language outcomes. In this mini review, we summarize the current pediatric literature independently connecting ELA and sleep to language development, as well as the effects of ELA and sleep on language-relevant aspects of brain structure and function. We then propose a framework suggesting that sleep disturbances and subsequent effects on brain structure and function may act as key mechanisms linking ELA and language development. Future research investigating the associations among ELA, sleep, brain, and language development will refine our proposed framework and identify whether sleep should be included as an intervention target to mitigate the effects of early life adversity on language development.

Night Sleep, Parental Bedtime Practices and Language Development in Low-Risk Preterm and Full-Term Late Talkers: A Longitudinal Study in the Third Year of Life

Background: Studies on night sleep and parental bedtime practices and their associations with language development in populations at risk of language delay and neonatal conditions, such as late talkers and preterm children, are scarce. Objectives: Our objective was to longitudinally examine the development of night sleep (total night sleep difficulties, settling, night waking, and co-sleeping), parental bedtime practices (total parental bedtime practices, active physical comforting, encouraging autonomy, and leaving to cry), and expressive language (word and sentence production), and their associations in low-risk preterm and full-term late talkers from 31 to 37 months of age. Methods: Parents of 38 late talkers, 19 low-risk preterm and 19 full-term children, completed the Italian versions of the Infant Sleep Questionnaire, the Parental Interactive Bedtime Behavior Scale, and the MacArthur-Bates Communicative Development Inventory Words and Sentences Long Form. Results: Late talkers' night sleep difficulties, such as settling to sleep and night waking, decreased over time, with low-risk preterm late talkers experiencing more night waking and co-sleeping than full-term peers. Parents reported that instances of active physical comforting and leaving to cry also decreased, with parents of low-risk preterm late talkers reporting higher active physical comforting scores than parents of full-term peers. Improvements in parental practices of encouraging autonomy were significantly associated with increased sentence production from 31 to 37 months. Conclusions: Findings highlight the importance of monitoring night sleep in preterm and full-term late talkers. They also suggest that populations vulnerable to sleep and language delays may particularly benefit from targeted interventions promoting autonomy in their bedtime routines, which, in turn, could support their language development trajectories.

Sensory processing in typically developing toddlers with and without sleep problems

This study investigates the sensory processing of typically developing toddlers with and without sleep problems. The research group consisted of typically developing toddlers with sleep problems (n = 110, mean age=18.35 ± 3.4 months), while the control group included typically developing toddlers without sleep problems (n = 110, mean age=18.67 ± 3.5 months) and their mothers. Toddlers were assigned to the research and control groups based on their sleep problems, as determined by the Brief Infant Sleep Questionnaire. The sensory processing of the toddlers was evaluated using the Infant/Toddler Sensory Profile 2. Sensory patterns and sensory processing sub-parameters of the research and control groups were compared. The sensory processing of the research group showed atypical behavioral responses in low registration (low awareness or indifferent attitude to sensory stimuli), sensory sensitivity (distracted or irritable attitude, intensely stimulated by sensory stimuli), and sensory avoiding (intentional avoidance of sensory stimuli or attitudes that produce out-of-norm responses) patterns compared to the control group (p < 0.05). Behavioral responses were similar in the sensory seeking (disturbing or dangerous attitude to the environment in search of sensory stimuli) pattern (p > 0.309). Statistically significant differences were observed in all sub-parameters of sensory processing compared to the control group. Our findings indicate that toddlers with sleep problems are at risk for sensory processing issues. Toddlers with sleep problems exhibit atypical sensory responses related to sensory sensitivity, low registration, and sensory avoiding. It should be considered that toddlers with sleep problems may show sensitivity to different sensory stimuli, avoidance or may not be able to recognize sensory stimuli. These findings suggest that the inclusion of sensory profile assessments in interdisciplinary care for toddlers with sleep problems may contribute to parent-infant well-being.

From co-regulation to self-regulation: Maternal soothing strategies and self-efficacy in relation to maternal reports of infant regulation at 3 and 7 months

This study, conducted in Germany, examines the role of maternal soothing strategies to explain the association of maternal self-efficacy with infant regulation (crying and sleeping behavior). Questionnaire data of 150 mothers, living in Germany, with mixed ethnic and educational backgrounds were collected when infants were 3 and 7 months old. Two types of maternal soothing strategies were distinguished: close soothing, involving close physical and emotional contact, and distant soothing, involving physical and emotional distancing from the infant. A cross-sectional SEM at 3 months indicated that maternal self-efficacy is associated with reported infant regulation through distant soothing strategies. Low maternal self-efficacy was associated with frequent maternal use of distant soothing, which in turn was related to reported infant regulation problems, that is, non-soothability and greater crying frequency. Frequent use of close soothing was associated with reported infant sleeping behavior, that is, frequent night-time awakenings. A longitudinal SEM further indicated that the effects of close soothing persisted at least until the infants' age of 7 months. The study showed how low maternal self-efficacy, increased use of distant soothing, and reported early infant regulation problems are intertwined and that, due to their persisting positive effect on infant soothability, close soothing better supports infant development.

Early Sleep Differences in Young Infants with Autism Spectrum Disorder

OBJECTIVE

Children with autism spectrum disorder (ASD) experience greater sleep challenges than their neurotypical peers, but sleep patterns for infants later diagnosed with ASD are unknown. This study examined differences in total sleep duration and proportion of sleep experienced at night within the first 6 months of life among infants later diagnosed with ASD, infants who demonstrated subclinical characteristics of ASD and were classified as exhibiting the broad autism phenotype (BAP), and their typically developing (TD) peers. In addition, associations between infant sleep variables and developmental outcomes at 24 months were explored.

METHODS

Participants included 79 infants enrolled in a prospective, longitudinal study of the early development of ASD. Between ages 1 week and 6 months, participants completed a monthly retrospective 24-hour sleep log. At 24 months, participants received a comprehensive diagnostic evaluation, including the Autism Diagnostic Observation Schedule-2 and Mullen Scales of Early Learning and Vineland-II and were clinically characterized as ASD, BAP, or TD.

RESULTS

When accounting for the influence of age, infants later diagnosed with ASD slept less within the 24-hour period than infants in TD or BAP groups from 0 to 6 months ( p = 0.04). Percentage of sleep experienced during nighttime hours did not significantly differ between groups from 0 to 6 months ( p = 0.25). Greater nighttime sleep percentage at 6 months predicted higher receptive language ( p < 0.001) and fine motor scores ( p < 0.0001) at 24 months. Total sleep duration at 6 months did not predict any developmental outcomes at 24 months.

CONCLUSION

Findings suggest that differences in sleep may occur among autistic individuals earlier in life than previously documented and have cascading effects on development.

Night Sleep and Parental Bedtime Practices in Low-Risk Preterm and Full-Term Late Talkers

Night sleep and parental bedtime practices have rarely been investigated in late talkers. This study aimed to explore: night sleep, parental bedtime practices, and their associations in late talkers as well as individual, socio-demographic, and socio-relational factors affecting them. Parents of 47 30-month-old late talkers, born low-risk preterm (n = 24) or full-term (n = 23), with an expressive vocabulary size ≤10th percentile measured by the MacArthur-Bates Communicative Development Inventory Words and Sentences, and normal cognitive abilities measured by the Bayley Scales, completed the Infant Sleep Questionnaire, the Parental Interactive Bedtime Behaviour Scale, and the Parenting Stress Index Short Form. Results showed slight settling difficulties, night wakings, and frequent co-sleeping in late talkers. Encouraging autonomy practices were frequently used by parents, rather than active physical comforting ones. Recurrent settling difficulties were reported by parents who often applied encouraging autonomy practices, whereas greater night waking problems and frequent co-sleeping were reported by parents who often left their child crying. Low-risk preterm birth and mother's parenting stress predicted total sleep difficulties and night wakings; first-born, high maternal education level and mother's parenting stress predicted settling difficulties; mother's parenting stress was the only predictor for co-sleeping and leaving to cry. These findings have relevant implications for improving late talkers' night sleep and their parents' bedtime practices.