Whilst they are sleeping they are growing. In NNICU, Abby was rarely awake. Even in SCBU she slept most of the time. Once she was home she remained on her 3 hour schedule. Up, feed, play for 45 minutes, sleep for 2 and a quarter hours. They just don't have the stamina for any more than that.
Right up until about 4 months ago, she struggled being up for more than and hour and a half at a time. At the moment we can just about take her to 3 hours before she is whinging for a sleep.