A newborn should learn to differentiate between day and night. For them it is not easy, at first, his time of sleep was decreased equally during the day and at night, this may take between one and two months. At this stage of growth may also occur bowel cramps and pains that make it very difficult dream small. 
From 6 months babies start to sleep through all the stages of sleep as adults. It's when they start to sleep better. 
At 8 months the baby is aware of the gap with their parents at night and when you wake up angry and distressed, is a hard stage but will spend all babies. A growth which adds something to the teeth can cause fever and malaise are making the dream will suffer. 
At Original we offer several models for bassinet sheets that will fit the needs of the mother.