CULTURAL VARIATIONS AND SOCIAL ENVIRONMENT AFFECT SLEEP HABITS – EARLY IDENTIFICATION AND INTERVENTION CAN PREVENT FURTHER SLEEP PROBLEMS

Along with nutrition, physical activities, and secure attachments, sleep is a basic requirement for a child's growth and brain development. Sleep plays a critical role in physical health and well-being, especially for growing infants and young children. Yet, sleep difficulty is one of the most common issues reported in infancy and toddlerhood.

Infants' sleep quality is highly variable during the first two years of life. Changes in sleep quality during development are extensive. Infants do not show a regular "day-waking, night-sleeping" pattern until about four months.

Hence, parents need to be aware of the reasons behind infants' sleep quality and patterns and possible sleep interventions.

Bedtime problems and frequent night waking are common sleep problems in infants and toddlers. Such problems, categorised as Behavioural Insomnia of Childhood (BIC), lead to insufficient sleep, contributing to multiple domains of child dysfunction. Behavioural treatments of BIC, such as extinction (a sleep training technique that involves putting your baby in the crib fully awake and allowing her to fuss or cry until she falls asleep, without help from you) and positive routines are introduced, and supporting evidence is reviewed.

Critical factors in developing a successful treatment plan include conducting a detailed assessment, collaboratively developing a plan that starts where the family is and providing support between sessions. One case of a 3-year-old girl with BIC illustrates how treatment helped her to develop healthy sleep habits and taught her to sleep independently.

Consistent bedtime routines and bedtime stories help her to sleep better eventually.

Sleep-related infant deaths, such as Sudden Infant Death Syndrome (SIDS), remain a major public health issue. In the United States (US), SIDS is the leading cause of death among infants (aged 28 days to 11 months), with a rate of 22.2 deaths per 100,000 live births in 2010.

Certain sleep practices (placing infant prone/face-down to sleep, sharing a sleep surface, having soft bedding or other items in the crib) have been associated with increased risk for sleep-related infant deaths.

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4. American Academy of Pediatrics [AAP]. (2011). SIDS and other sleep related infant deaths: Expansion of recommendations for a safe infant sleeping environment. Pediatrics, 128(5), 1030–1039.

Since 1992, the American Academy of Pediatrics (AAP) Taskforce on SIDS has reviewed the evidence and provided the most recent safe sleep recommendations. Adherence to safe sleep recommendations to reduce the risk of sleep-related infant deaths remains low. Thus, interventions aimed at reducing risky behaviours are being implemented.

Swaddling promotes quiet sleep and may be a useful strategy to encourage infant safe sleep practices. Researchers explored the effect of a swaddling education intervention on infant sleep practices in an urban minority community.

They compared a cohort of postpartum mothers who were given education about swaddling to a historical group. Compared to the historical group, mothers in the swaddling group were more likely to swaddle infants to sleep and less likely to bedshare. No significant effect was reported on infant supine sleep.

A postpartum swaddling education intervention had a limited impact on infant safe sleeping practices in an urban minority community. A recent meta-analysis demonstrated an increased risk of sudden infant death in infants swaddled for sleep. It recommended the need to avoid the prone and side sleep position, especially for swaddled infants, and to set an age and developmentally appropriate limit for the use of swaddling. Ongoing studies are needed to monitor the safety and effectiveness of swaddling as a tool to promote safe sleeping in infants.

Both "graduated crying-it-out" (extinction) and "bedtime fading strategies" (bedtime fading involves temporarily moving bedtime to more closely coincide with the child's natural sleep onset, to ensure rapid sleep initiation) helped babies (4 months and older) fall asleep faster, compared to babies whose parents who received information about infant sleep (but did not implement any specific strategies).

In a random controlled trial study, researchers compared 43 infants (6-16 months, 63% girls) to receive either "graduated extinction", "bedtime fading", or "sleep education" control.

Sleep measures included parent-reported sleep diaries and infant actigraphy (a non-invasive method of monitoring human rest/activity cycles). Infant stress was measured via morning and afternoon salivary cortisol sampling and mothers' self-reported mood and stress.

Twelve months after the intervention, mothers completed assessments of children's emotional and behavioural problems, and mother-child dyads underwent the Strange Situation Procedure to evaluate parent-child attachment.

Significant interactions were found for sleep latency, number of awakenings, and wake after sleep onset. Salivary cortisol showed small-to-moderate declines in graduated extinction and bedtime fading groups compared with controls. Mothers' stress showed small-to-moderate decreases for the graduated extinction and bedtime fading conditions over the first month, yet no differences in mood were detected. At the 12-month follow-up, no significant differences were found in emotional and behavioural problems and no significant differences in secure-insecure attachment styles between groups. Findings suggest that sleep strategies do not cause attachment issues in children.

Sleep habits with infants could lead to sleep problems which can be persistent over time up to adulthood. Researchers aimed at describing infant sleep characteristics: total sleep time (TST)/24 h, night waking (NW), and sleep onset difficulties (SODs). They then associated sleep habits in infants at age 1 year from the French nationwide birth cohort Etude Longitudinale Française depuis l'Enfance (ELFE).

This study included 11,783 infants with information on sleep characteristics and sleep habits (parental presence when falling asleep, eating to fall asleep, sucking a pacifier or finger to sleep and sleep arrangement and location).

Findings showed mean TST was 13 hours 36 minutes, including 2 hours 54 minutes of naps; 20 per cent of the infants had TST 12 hours of sleep. About 46 per cent did not present SOD or NW, 16 per cent had frequent SODs, and 22 per cent had NW. Parental presence, feeding to fall asleep, and infant sleep arrangements were frequent in infants with short sleep duration (less than 12 hours a day), NW and SODs. Non-nutritive sucking was associated with risk of NW, SOD and TST more than 14 hours a day. Parental room-sharing was associated with NW.

However, cultural variations (rather than poor sleep habits) influence sleep patterns in young children across culturally diverse countries/regions. A 2017 study characterises cross-cultural sleep patterns and sleep problems in a large sample of children ages birth to 36 months in multiple predominantly-Asian (P-A) and predominantly-Caucasian (P-C) countries.

Parents of 29,287 infants and toddlers (predominantly-Asian countries/regions: China, Hong Kong, India, Indonesia, Korea, Japan, Malaysia, Philippines, Singapore, Taiwan, Thailand, Vietnam; predominantly-Caucasian countries: Australia, Canada, New Zealand, United Kingdom, United States) completed an Internet-based expanded version of the Brief Infant Sleep Questionnaire. Findings suggest that children from P-A countries had significantly later bedtimes, shorter total sleep times, increased parental perception of sleep problems, and were more likely to both bed-share and room-share than children from P-C countries.

The social environment can also influence babies' sleep. In many western countries, parents try to get their babies to sleep through the night around 4 months of age by offering an evening feeding before putting them down in a separate, quiet room.

In this way, young infants are being pushed to the limits of their neurological capacities. The secretion of melatonin, a hormone within the brain that promotes drowsiness, is greater at night than during the day at the middle of babies' first year.

Parents and infants can co-sleep safely with appropriate precautions to prevent SIDS.

In cultures where co-sleeping is widespread, parents and infants usually sleep with light covering on hard surfaces, or infants sleep in a cradle or hammock next to the parents' bed.

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12. McKenna, J. J. (2002). Breastfeeding and bedsharing still useful (and important) after all these years. Mothering, 114.

When co-sleeping on the same bed, infants typically lie on their back or side facing the mother. These are positions that promote attachment and frequent, easy communication between parent and baby and arousal if breathing is threatened.

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9. Berk, L. E. (2017). Exploring lifespan development. Pearson.

The ways that parents and caregivers interact with infants and toddlers and the experiences they provide could be the key to good sleep. Researchers investigated relations between children's attachment and sleep.

55 mother-child dyads took part in the Procedure (18 months) to assess attachment. At 2 years, children wore an Actiwatch for a 72-hour period, and their mothers completed a sleep diary.

More resistant attachment behaviour was not associated with actigraphy-assessed sleep but was associated with longer nocturnal wake duration as estimated by mothers and reduced actigraphy-diary discrepancy. Mothers of children with resistant attachment are also more aware of their child's nocturnal awakenings. Findings suggest that children who display secure attachment can sleep better than those who display resistant attachment behaviour.

Sleep difficulties are common in young children during the first two years, especially when babies are getting mobile and curious about their environment. Two 2020 studies investigated the validity of the Brief Infant Sleep Questionnaire (BISQ) in assessing sleep quality in childhood.

In one study based on two birth cohorts that comprise representative samples of families were recruited systematically during pregnancy to describe the normative development of sleep at 3, 6, 8, 12, 18 and 24 months in healthy children. Researchers found that sleep quality is highly variable, particularly during the first two years of life, but this variability decreased markedly towards the second year.

Young children (especially below the age of 2) should not be exposed to screen time as TV viewing by infants and toddlers may be associated with irregular sleep.

When babies and young children watch television, their brains are stimulated by the animated scenes appearing on the television. There will be overexposure to light which affects their vision at a young age. When babies watch TV in the evening, their body clocks can be tricked into thinking it is daytime by the light coming from the television. For older children, the issue often becomes fighting to stay awake to watch the end of a show. Then, they miss that sleep window, and their body secretes a stress hormone called cortisol, which keeps them awake. The cumulative problem of lack of sleep leads to less sleep, and the vicious cycle goes on.

As sleep development is associated with cognitive and physical growth, it is important to establish bedtime routines since infancy. In a 2017 narrative review, researchers provide an overview of the relation between infant sleep and cognitive development and physical growth.

Findings indicated a positive association between sleep, memory, language, executive function, and overall cognitive development in typically developing infants and young children.

An additional 20 studies support the positive role of infant sleep in physical growth, with the current literature focusing largely on weight gain and obesity rather than healthy growth. The existing evidence in both domains is mainly based on cross-sectional designs, on association studies, and on parental reports.

Sleep deprivation will eventually lead to poor developmental outcomes. A researcher revealed that children who do not get enough sleep could mistakenly be thought to have attention deficit hyperactivity disorder (ADHD).

Children who do not have a regular bedtime are more likely to have ADHD-like behaviours. Poor sleep is also linked to obesity and impaired immune function. Healthy practices for sleep, including those that reduce the risk of Sudden Infant Death Syndrome (SIDS) and Sudden Unexplained Infant Death (SUID), support child health and family well-being. By becoming knowledgeable about sleep, one can help busy families lay the foundation for lifelong healthy sleep habits.

Early identification of the precursors, correlates, and outcomes of child sleep problems are important. Researchers stated that there are numerous longitudinal studies indicating that childhood sleep problems are associated with a range of adjustment, executive attention, and academic difficulties later in development.

Studies of non-clinical populations indicate that sleep problems (difficulty initiating or maintaining sleep) that emerge during early childhood tend to persist later in development. For example, 41 per cent of infants in a community-based sample who had sleep problems at age 8 months still had sleep problems at age 3 years.

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21. Zuckerman, B., Stevenson, J., Bailey, V. (1987). Sleep problems in early childhood: Predictive factors and behavioural correlates. Pediatrics, 80, 664–671.

Hence, intervention programmes should pay attention to the generalisability of previous study findings, cultural variations and tailor interventions to their target population. Studies on safe sleep interventions should include rigorous evaluation methods, for example, using comparison groups, to help demonstrate effectiveness.

Creative methods for measuring adherence to safe sleep recommendations, beyond just self-reports of behaviours, are needed.

Quality caregiving, interactions and play, and providing a safe and secure environment for the baby should be emphasised.