When I take on clients with premature babies I remind them that no matter how well the babies are doing they are still catching up with growth in that first year. All babies that were born before 37 weeks will have an extended time of newborn sleep, and about two-third of their early days are in active sleep. After the third month sleep stages are a little more defined and wake/sleep/eat patterns start to mimic those of a term baby.
So how do I determine the sleeping patterns? Most doctors will subtract the due date with actual age using an adjusted age which will then determine the sleeping pattern for that baby. Lets say a baby was born 4 weeks preterm he will probably have a sleeping pattern of a new born until the start of the third month for example. It is important to help your little one with a gentle routine that prepares them naps and night sleep because even at 9 months they release less melatonin than term babies and the natural urge to sleep will be lower.
A few tips to help regulate sleep patterns
1) Try a morning nap outside in the stroller - The light from sleeping outside for the first nap helps set the circadian clock for that day
2) Proprioceptive massage - The Proprio system in the human body tells the brain the body's position in relationship to the outside world sending info to brain from cell receptors (called proprioceptors) located in the skin, muscles, tendons, ligaments, and joints. This sends important clues to help them learn about their bodies, how to move their limbs in relationship to the gravitational force, and discover a sense of orientation.
3) Introduce a bedtime routine from day 1 following the same order every night - Time may need to be adjusted here and there, especially when naps prior to the night sleep are a little off. By setting a series of markers a baby knows what to expect and it helps signal that now is the time for night sleep.
4) Patience - Whether premature or not it takes time to grow into a regular sleep pattern. You will find that their routine wont always run like clockwork in the first year as milestone and cognitive leaps come at slightly different times than babies that were born term.