Infant Sleep & Sleep Association

Why do infants and young children wake so often in the night time? Is night waking a problem? Why some of them can’t go back to sleep on their own and rely on caregivers to help them fall back to sleep? What is sleep association and its role in perpetuating night wakings? What can be done to deal with bedtime problems and night wakings?

The effects of screen time on children’s health

Infant nighttime wakings are related to sleep phases

Newborns usually sleep throughout day and night. By 6 weeks of age, infants show day-night difference in their sleep-wake pattern and by 12 weeks of age, clear signs of day-night rhythm are reported. This means they are more able to sleep for longer periods at night with more waking time in the day. Night wakings,in fact, are common in infants and related to one of the sleep phases, active sleep. During active sleep, shallow and irregular breathing, twitching of arms and legs are noted with eye muscles and head movements. This is the phase infants may be aroused easily. Throughout the night, infants’ sleep alternates in cycles of active and quiet phases, with each cycle lasts about 20-50 minutes in infancy and extends longer gradually till school age 1. Infants and children do briefly wake at the end of each sleep cycle. Such brief arousal, therefore, is a normal part of sleep 2, 3.

The problem lies in infants’ inability to self soothe rather than night wakings per se

By 8 months old, infants usually wake every 6 to 7 hours, and 60%-70% are able to self soothe (i.e. to get themselves back to sleep) 4. Studies show that about 25%-50% of 6- to 12-month-olds and 30% of 1-year-olds have night wakings. Hiscock and Wake (2001) found that 46% of surveyed mothers reported they were experiencing problem related to sleep of infants 5. Frequent night waking is particularly common in infants aged 4 to 12 months. Night wakings are not problematic per se but many caregivers may find it disturbing. Often, they find their children crying or fussing about to signal to them for attention before the children could fall asleep again with their help. Prolonged and inconsolable crying, resistance to soothing and settling and other sleep problems of infants are found to have significant burden on parental mental and physical health, and parent-child relationship 6.

Sleep association at bedtime

According to Mindell (2010), whether a child is a "self-soother" or "signaler" is highly influenced by the appropriateness of the sleep onset associations, which are the conditions that are present when children’s sleep starts and required for them to fall back to sleep after periodic nighttime wakings. The ability to self soothe is related to the caregiver’s practice of putting the child to bed while he is drowsy but still awake. This avoids the child associating sleep onset with being rocked, patted and/or held. If an infant is used to fall asleep by being held,patted and/or rocked, he may cry in the periodic night wakings when he finds that the sleep onset condition has changed. Caregiver, who then responds immediately with holding and patting again, may create a reinforcing condition and increase the likelihood of signaling behaviours to occur in the future. Eventually the infant will turn more and more into a ''trained night crier''. The persistence of inability to self-soothe and caregivers’ reinforcement is found related to sleep disruption in infants and children.

Establishment of sleep habits

  1. Sleep and nap schedule

    Infants need taking day naps. The number of naps gradually decline to one or none by age 5. Inadequate sleep and excessive time in bed are associated with increased night arousals. Caregivers should ensure their infants have adequate sleep during the day which fits their developmental needs, and avoid sleep deprivation. A consistent bedtime at night helps reinforcing the circadian sleep-wake rhythm and enables the child to fall asleep more easily.

  2. Consistent bedtime routine

    Caregivers can start establishing bedtime routine when their children are about 2-3 months old. Soothing activities such as bathing, story-telling, gentle play, singing lullabies and listening to soft music can be arranged 20-45 minutes before sleep. These activities should be calm and enjoyable without exciting the child or involving vigorous activity. Positive parent-child interaction without relying on television, videos or other screen devices can act as a bedtime ritual. Some infants find bathing a soothing activity while others may become increasingly alert and excited. The activities chosen, therefore, are subject to the child’s preferences,needs and his responses. Activities occur closest to “lights out” should be arranged in room where the child sleeps. Besides, providing a comfortable sleep environment and emphasizing the day-night difference are equally important in enhancing the sleep of infants.

Management of sleep association and night wakings

When the child wakes in the middle of the night, caregivers should first make sure that the child is safe and has no genuine needs such as being hungry, having a soiled nappy or feeling too hot. Infants no longer require nighttime feeding usually by 6 months old, so the need of feeding is unlikely by that age. Caregivers can then use the “wait & see approach”, i.e., avoiding responding to the child’s night signals immediately to allow the child to return to sleep independently without reinforcing night wakings.

If the child needs to settle with sleep associations and fails to self soothe after waking at night, caregivers can try the following options to suit their needs:

  1. Controlled comforting / Graduated extinction

    The essence of this method is the caregiver awaits progressively longer period of time before checking on the child and spends only a short time settling the baby and places him being drowsy but awake in bed alone. The step-by-step procedures can be found at “If Your Baby Cries during the night (referring to point 1)”

    On each subsequent night, the time interval between checkups increases. Caregivers should not stay close or near the infant when using this strategy.

    For older children above 2, caregivers may have to set clear limits with reinforcement strategies (e.g. stickers are rewarded immediately in the morning if the child is able to sleep in his own bed all night) to establish and maintain appropriate sleep habits and self-soothing skills.

  2. Systematic ignoring / Extinction / “Crying it out”

    This is similar to controlled comforting but is a stricter and tougher approach in which caregiver places the infant in bed at consistent bedtime and systematically ignoring the child when he signals or cries. Caregivers may check if the infant is not sick or in need of a nappy change, then may leave him crying no matter how long it lasts (refer to “If Your Baby Cries during the night - point 3)”. It involves much energy and commitment from all caregivers and may not be feasible with certain environmental constraints.

    Caregivers should be prepared for “extinction burst”, i.e., an initial increase in intensity and duration of signaling and crying behaviours. Such behaviour is regarded as normal when using this approach and will fade out when caregivers consistently and persistently applying the strategy.

  3. Camping Out

    It is also similar to controlled comforting but is a gentler approach. The caregiver stays with the child in the room. As the child learns to independently fall asleep, caregiver’s presence is slowly removed from the child’s room (refer to “If Your Baby Cries during the night - point 2)”. This technique takes longer time to work and requires more persistence and energy fromcaregivers.

    Information regarding when to use these interventions and expected time for improvement can be found in the website of the Centre for Community Child Health Australian practice resource.

    The above behavioural techniques are supported by research evidence to be effective in managing bedtime problems and night wakings of young children 4, 7, 9. However, there is insufficient data to support the effectiveness by any single method 9. In fact, successful management involves a combination of techniques. Apart from choosing a behavioural intervention or strategy that suits the family, other strategies to be considered include providing parent education about prevention of sleep problems, establishment of appropriate bedtime routines and sleep habits, and caregivers' capacity to implement the strategies consistently and persistently 1.

    No harm on the child when using sleep interventions

    Caregivers may concern about whether the above interventions may do harm on the emotional and mental health aspects of children. Results from a long-term follow-up study did not support the belief 8 of any long-term harm to the child, parent-child or maternal outcomes. On the contrary, positive secondary outcomes are found regarding children’s daytime functioning and maternal well-being after behavioural interventions 9. Child-related professionals can feel comfortable providing advice to caregivers applying the strategies to deal with sleep problems of infants.


“Positive routine / faded bedtime with response cost” 4, 7, 9 can be used for children aged 12 months or above who display resistance to settling when they are put to bed at night. Caregivers first develop a set of enjoyable routines preceding bedtime which acts as a behavioural chain leading to sleep onset (refer to “Establishment of sleep habits: B. Consistent bedtime routine”). If the child does not fall asleep, delayed bedtime with response cost will be carried out by temporarily moving the child out of bed. Bedtime is delayed to the time closer to the start of sleep. Once the behavioural chain is built up and the child is falling asleep quickly, the bedtime is shifted earlier by 15 or 30 minutes over successive nights till a pre-established bedtime goal is achieved. In the meantime, a scheduled wake time is to be established and daytime sleep is not allowed except for the age-appropriate naps.