Understanding infant sleep patterns & stages

When you have a baby, sleep becomes the "holy grail" for new parents. But if your baby won't settle at night, you won't get any sleep either - and suddenly, the whole family descends into a spiral of sleep-deprived misery. Sleep specialist Dr Alex Bartle gives us the lowdown on infant sleep.

Struggling with sleepless children is not a new phenomenon for parents, but increasingly, in our busy and stressful society, parents need to maintain adequate sleep themselves. Parental exhaustion clearly has an impact on how we care for our babies. Almost daily, I receive calls from exhausted and distressed parents desperately seeking advice about their child who will not sleep.

The most common time that adults first experience significant sleep deprivation is with the birth of their first child. After those initial days of exhilaration, the reality of caring for this dependent baby 24 hours a day sets in, and no matter how many books you have read, it comes as a shock. Sleep deprivation, an aching pelvis, and sore nipples are not a happy combination for a new mother. Added to this is the isolation new parents frequently feel. Family and friends call in to pay homage to the new arrival, but getting out of the house is often difficult for the new mother and baby, especially in the early days when feeding is still being established. With her partner back at work, there may be little social contact for a new mother for weeks on end. Add to the equation the baby who will not settle, and you have a recipe for unhappiness.

There are a number of factors involved in establishing good infant sleep patterns. One of the most powerful is the baby's personality. Although this cannot be changed, the environment and parenting style have a large bearing on a baby's sleep. This issue is complex, and there is rarely one answer. Sleep is an active, restorative process vital for physical and mental growth. Unfortunately, babies don't read books or tell the time, so it rests with parents to guide and teach babies to obtain adequate sleep.

So, how can you help your baby to sleep? To answer this, an understanding of babies' sleep patterns may help. Their sleep can be roughly divided into developmental stages.

Development
0-4 months
During this time, there are major changes that are relatively consistent. For the first few weeks, the baby's sleep pattern is likely to be erratic. A baby does not recognise a 24-hour cycle or "circadian rhythm". He has been receiving constant nourishment from his mother in the womb, and is likely to continue this pattern, demanding milk frequently as a newborn. Feeding and sleeping are the main preoccupation. Total sleep time is likely to be between 16 and 20 hours of each 24-hour period.

Sleep at this time comprises 50% Rapid Eye Movement (REM) or "active" sleep, when the baby twitches his arms and legs, makes sucking motions with his mouth, and moves his eyes rapidly from side to side. REM sleep is light, and the baby can be easily roused, or may rouse himself from this level of sleep. The amount of REM sleep reduces steadily throughout the first year.

Until about four months of age, the other form of sleep is "quiet" or non-REM sleep. This is generally a deeper, calmer, and more relaxed sleep. By the age of six weeks, this fragmented sleep will start to become more organised, and by 12 weeks a definite night/day pattern usually emerges. This distinction between night and day can be assisted by developing some routine, such as taking the baby outside into the light for some time during the day, and ensuring darkness in the bedroom at night.

4-8 months
A baby's sleep patterns will become more regular, and after six months, the mother can work with her baby to develop a routine that works for both of them. Careful observation of the baby's sleep needs is essential to this process. By this stage, the baby will require between 14 and 16 hours of sleep. This will include at least two shorter daytime naps adding up to about five hours total, and one longer night-time sleep of about 10 hours. Although many mothers will be happy to continue the night feed throughout this time, from a nutrition point of view, the baby rarely needs a night-time feed after the age of six months. Sleep cycles are still short at this time, lasting about 60 minutes, compared to the older child and adult cycle of 90 minutes. At around six months, your baby will start solids. This may assist in prolonging the night-time sleep, but you should never start solids early in the hope it will help your baby sleep.

8-18 months
At about eight to 10 months of age, the baby may become quite clingy. No longer is he so happy to be passed from one relative to another, or among friends. Babies develop what is known as "separation anxiety". While he may have been a brilliant sleeper until this time, he now doesn't want to be left alone. This may result in the demand for parental attention during the night, despite the fact he does have the innate ability to get himself back to sleep at this age. Daytime naps may also become shorter, with the morning nap taking place later and later until, by about 18 months, the two naps merge into one early afternoon nap. This transition from two naps to one nap is often difficult to manage, but the infant will usually make that decision, and there's not much the parent can do about it. The night-time sleep becomes more consolidated, to between 10 and 12 hours, and the daytime naps add a further two to three hours. The longer the daytime naps can be maintained, the better. Research and observation have demonstrated that the idea of keeping the child awake throughout the day to make him more tired at night does not work. A rested, calm child is more able to fall asleep at night than one who is overtired and irritable.

Routine
A good routine is fundamental to the development of a good sleep/wake cycle. Again, it is dictated to some degree by the developmental age of the baby.

0-3 months
Initially, there is little routine. A baby will fall asleep any time and anywhere, and is unlikely to fit conveniently into your own previous routine. Keep your expectations to a minimum in order to reduce disappointment and upset. Avoid creeping about when the baby is asleep, as it's unlikely that regular background noise will wake the baby, or prevent him from going to sleep. Grab sleep whenever you can, but remember, the baby rules!

Some parents choose to sleep with their baby, known as "co-sleeping". Recent research in Dunedin reports that babies who co-sleep generally wake more frequently but for less time, and are often less disruptive to their parents' sleep. There are arguments both for and against co-sleeping and as long as certain precautions are taken, it can be both safe and rewarding.

3-6 months
Between three and six months, some routine may be established. This should involve developing a distinction between day and night. Before the night-time sleep, a bath and massage are soothing for the baby. Feed him in a quiet, dim environment as opposed to the daytime feeds, which can be in a brighter environment. Keep the bedroom warm at night (18 to 20°C), and keep the baby lightly clothed in order to avoid him becoming too cold or overheated. Attend to your baby when he cries. At this stage, it will be the comfort he needs to get back to sleep, and his brain is not able to think beyond basic survival needs.

6-12 months
From about six months of age, routine becomes more important. The baby should still be having an afternoon nap, and wake refreshed and happy. From about 6pm onwards, watch for signs of tiredness. These signs may start with being fussy, irritable and crying at the slightest obstacle. Rubbing eyes, yawning and pulling at the ears are also signs to watch for. When this happens, check the time and, in the future, begin the evening routine about half-an-hour before that time.

A well-documented and useful bedtime routine often begins with a bath followed by a brief massage, then quiet time as the infant has his last feed of the day. This will usually result in the baby becoming drowsy, and he may even fall asleep.

Generally he will remain asleep when placed into his cot if the transition is not too rushed. Wait until the baby is relaxed and floppy. If you are putting him to bed while still awake, as is often recommended, singing or reading a story will help soothe him to sleep. Generally, the fewer interventions you need to help your baby sleep, the more likely he will to be able to get back to sleep by himself if he wakes in the night.

Dr Alex Bartle is a GP who has specialised in sleep medicine. He now runs the Sleep Well Clinics in Auckland, Wellington and Christchurch. Alex practised GP Obstetrics for 30 years. He is a father of two and stepfather of four. Visit www.sleepwellclinic.co.nz for further information.