Babies, like us have sleep rhythms made up of active and quiet sleep cycles.
Active sleep is a sleep phase which involves head and muscle movements, similar to rapid eye movement (REM) in adults.
Quiet sleep is a sleep stage in which the muscles are relaxed. Limbs are still, and breathing is deep and regular.
Babies cycle in and out of quiet sleep, and are less likely to wake during this stage.
In the early months of life, baby sleep tends to be 50 per cent active sleep and 50 per cent quiet sleep, often waking after phases of active sleep.
At around three months, the amount of active sleep decreases. Babies also begin to enter quiet sleep at the beginning of their sleep cycles.
At this age, the sleep cycle for babies consists of alternating active and quiet sleep periods of 20–50 minutes each (compared with 90-minute sleep cycles for adults).
By six months, a baby’s sleep patterns are closer to those of a grown-up – which means less waking at night.
By eight months, 60-70 per cent of babies are able to self-soothe themselves back to sleep without a parent’s help. Others will continue to wake if they need help to settle back to sleep, or if their parents are continuing to feed them through the night.