Toddler sleep is something that many parents worry about, sometimes even more than infant sleep. One of the key worries is how much their toddlers are sleeping, or rather how little they are sleeping. Some toddlers just don’t seem to need much sleep, but then parents are bombarded with information about how a certain number of hours is necessary for optimal development. So they try to get their toddler to sleep more, often ending in more frustration and tears for all involved and probably no more sleep.
The problem for many has been that recommendations on toddler sleep are often based on parental report data and sadly that’s often pretty inaccurate, especially if toddlers are sleeping apart from their parents. However, a 2019 study in the journal Child Development may be able to provide some relief for parents about what really is going on with respect to our toddler’s sleep. The study itself was actually looking at the effects of sleep consolidation on cognition (spoiler: there was no effects of sleep consolidation on cognition so don’t worry if your toddler wakes at night), but what struck me about this study was that the sample was large enough and the sleep data complete enough to give us some pretty good information on the normal development of sleep in the toddler years, something that many parents are missing.
The research included children recruited at 30 months (so 2.5 years of age) and followed them for one year, gathering sleep data at 30, 36, and 42 months of age. The sleep data was gathered using actigraphy to avoid parental bias or mistakes and consisted of two weeks’ data at each time point to allow for an averaging of the nights. The number of children with sleep data at each time point was N=420, 324, and 276 for 30, 36, and 42 months, respectively. Considering there’s actigraphy involved, this is an excellent size sample for normative data.
So what is normal?
According to the actigraphy on this group of predominantly-Caucasian children (which does matter, but it is what it is so we have to accept it):
- Toddlers wake frequently. The average number of wakings that were longer than 5 minutes were 4.72 at 30 months and went down to 4.06 at 42 months. Yes, that’s right, at 3.5 years of age, kids were still waking an average of 4 times per night. Now, they were not waking their parents for all of these, but as evidenced by the wakings needing to be longer than 5 minutes to be counted, they weren’t super brief either. For families who co-sleep, they are more likely to notice these wakings than when toddlers are sleeping alone.
- Toddlers can be awake for a while. The average duration of the longest awakening was 31.18 minutes at 30 months, 25.77 minutes at 36 months, and 23.89 minutes at 42 months. So it was quite common for toddlers to have a longer awakening in the middle of the night which mirrors experiences of some families who co-sleep and worry about these longer wakings. How many of these kids got their parents during this time, we don’t know, but if you’re co-sleeping or your child wants to see you, chances are you’re being awoken.
- Later bedtimes are normal. Despite earlier bedtimes of around 8:50pm at all three ages, the average time of actual sleep onset was around 9:30pm at all three ages. This is something I have spoken at length to families about as later bedtimes actually are quite normative in the infancy and toddler years and is reflected in average bedtimes in other cultures. So no, you’re not a bad parent for having a bedtime that’s more in line with your child’s biology.
- They sleep less than we think. The average amount of time in bed was around 10.4 hours at all three ages, but the actual time asleep was 8.18 hours at 30 months, 8.43 hours at 36 months, and 8.51 hours at 42 months. The increase over time likely reflects a normal decrease in day sleep that tends to happen in that 2.5 to 3.5 year range. Now this includes the long time to fall asleep that most of these kids had so the time awake overnight isn’t quite this bad, but the fact that the kids are sleeping far less than we think is important for parents to be aware of. Too often we worry about kids needing things like 11-14 hours because this was based on inaccurate parental reports when in reality they are getting less than this and seem to be functioning just fine.
What do we take from this? Toddlers wake and generally sleep less than we think. Depending on many other factors such as whether or not you’re still breastfeeding or you co-sleep or your child just likes you a lot, they may or may not wake you during these periods. These wakings will decrease in time and you can rest assured that your wakeful toddler is normal, thank you very much. If you are worried, take a look at your toddler’s daytime behaviour and if all seems well, I wouldn’t worry about those times they just want to sing you the alphabet at 3am.
 Hoyniak CP, Bates JE, Staples AD, Rudasill KM, Molfese DL, Molfese VJ. Child sleep and socioeconomic context in the development of cognitive abilities in early childhood. Child Development 2019; 90: 1718-1737.