To understand a child’s sleep problem, you need to know something about the nature of a child’s sleep. A full term infant emerges from the womb already practiced in two distinct modes of sleeping known as active sleep and quiet sleep. The form called active sleep in newborn infants is also known as rapid eye movement sleep. It is distinguished by slight but frequent body movements, irregular breathing changes in facial expression and the easily visible rapid movements of the baby’s eyes beneath his closed eyelids. In older children, dreaming takes place during REM sleep. In the quiet sleep mode, the infant’s breathing is regular and deep, and most other body movement is markedly diminished. In the first month however you may see fast body twitches, called startles, and rhythmical sucking notions while the baby is sleeping in this state.
At birth a full term baby divides his sleeping time roughly in half between active and quiet sleep. Until the age of three months, the baby falls directly into active, REM sleep; after about three months, he falls directly into active, REM sleep; after about three months he falls first into non REM, or quiet sleep. During the first six months of life the quiet mode of sleep evolves into varying stages similar to that seen in older children and in adults. When the child is in the deeper stages of non REM sleep, he can be very difficult to awaken. It is this kind of sleep that enables you to dress him in his pajamas and tuck him into bed without waking him up when he falls asleep on the sofa or floor. By the time he is six months old his sleep moves through cycles of non REM and REM sleep in a way which will remain fairly constant throughout life. In his REM sleep he may awaken if only for a few seconds. He may open his eyes examine his surroundings and shift his position. He might do this as often as nine or 10 times a night.