Matthew Troester, DO
Specializing in Pediatric Neurology, Epilepsy, Sleep Medicine
The Experts Weigh In: How Long Should My Child Be Sleeping?
The single most-frequent question I am asked by parents is, "How much sleep does my child need?" My answer has always been enough that she or he is not falling asleep in inappropriate situations (like at school), enough that she or he seems rested upon awakening and enough that she or he seems happy most of the time. The number is obviously different for every child, and historically, we have not really had a single number of hours of sleep to prescribe, so to say.
The best data set we had regarding actual sleep duration is from a 2003 study*. It looked at 493 children in Zurich, Switzerland, who filled out sleep questionnaires every few months for the first two years of life and then annually for 16 years. The result was a “growth curve” for sleep. The graphs below show two things worth noting:
- Total sleep duration decreases as a child ages.
- Variability in sleep duration at a given age decreases with time.
For example, looking at the total sleep duration graph at one month of age, there is a huge range of sleep duration reported. Note the upper and lower solid lines and how many hours are covered (8.5 to 19 hours). Now, look at the 16-year-old data and the range of sleep duration is much more narrow (6.5 to 9.5 hours).
For some sleep doctors, these charts have been a useful guide as to how much sleep kids at various ages should be getting. Parents can, in theory, plot a child's sleep habits on the “growth curve” to get an idea if the child is within the range of typical (between the two solid black lines at the top and the bottom).
Is How Much Sleep We Get Consistent with How Much Sleep We Need?
The amount of sleep we get, as reflected in the above graphs, is not always consistent with the amount of sleep that is recommended. Some of the first documented sleep recommendations were published in the late 1890s!
Over time, two trends have been noted about our sleeping habits:
- We are sleeping less as time goes on
- Experts seem to recommend less sleep as time goes on
Matricciani and colleagues (Pediatrics 2012;129:548–556) reviewed 32 sets of recommendations dating from 1897 to 2009. The researchers found, “On average, age-specific recommended sleep decreased at the rate of –0.71 minute per year. This rate of decline was almost identical to the decline in the actual sleep duration of children (–0.73 minute per year). Recommended sleep was consistently 37 minutes greater than actual sleep, although both declined over time.”
So what the heck does that mean? Two things: First, we seem to be sleeping less. Also, it would seem that over the years, no matter how much sleep kids were getting, it has always been assumed it wasn’t enough.
Are we really sleeping less?
The answer is yes! As you can see from the above paragraph, it declines about 0.73 minute/year on average. That’s about 45 seconds, on average, less sleep per year over time.
If you look at the information from the 2003 study carefully, you will see that the data actually comes from two large groups of survey participants. One from the 1970s and one from the mid-1990s.
Check this out:
- In the mid-1970s, mean bedtime was 19:08.
- Inthe mid-1990s, mean bedtime was 19:46.
Wake times did not really change, but there was a substantial decrease (38 minutes) in sleep duration over time.
Why are we sleeping less?
Great question. There are many reasons.The main ones have to do with electricity and light.
Before widespread use of electrical lighting in homes, after the sun went down and lamps burned out, it was dark so people stopped working or whatever they were doing and simply slept till the sun came up. With all the artificial light we have now (think about the device you are reading this blog on now), we don’t follow the same light/dark rhythm and we can delay our bedtime because of the artificial light and its influence on how sleepy we might be.
The real question to ask is does it matter that we are sleeping less that we have historically? Are kids today simply better able to deal with less sleep than a century ago? Is there actually optimal sleep duration?
In 2015, the National Sleep Foundation released its recommendations for sleep duration over the lifespan.This information was determined by 18 scientists and researchers who came together to form an expert panel tasked with updating the official recommendations.The panelists included six sleep specialists and representatives from leading medical organizations.
In 2016, the following statement was released by the American Academy of Sleep Medicine and provides recommendations for how much sleep children should get to promote optimal health.To create this statement, I and 12 other sleep expert clinicians and scientists worked together to painstakingly review almost 900 scientific articles looking at how sleep duration influences health outcomes from a variety of domains ranging from cardiovascular health to mental health.
Through this exhaustive review of the current medical literature and subsequent vetting of the information process, we were able to say that while more age specific research is needed, not only is there such a thing as too little or too much sleep, but there is a range of sleep for most age groups that seems to be associated with optimum health:
- Infants** 4 months to 12 months should sleep 12 to 16 hours per 24 hours (including naps) on a regular basis to promote optimal health.
- Children 1 to 2 years of age should sleep 11 to 14 hours per 24 hours (including naps) on a regular basis to promote optimal health.
- Children 3 to 5 years of age should sleep 10 to 13 hours per 24 hours (including naps) on a regular basis to promote optimal health.
- Children 6 to 12 years of age should sleep 9 to 12 hours per 24 hours on a regular basis to promote optimal health.
- Teenagers 13 to 18 years of age should sleep 8 to 10 hours per 24 hours on a regular basis to promote optimal health.
** Recommendations for infants younger than 4 months are not included due to the wide range of normal variation in duration and patterns of sleep, and insufficient evidence for associations with health outcomes.
While it is nice for parents to have a frame of reference about how much sleep their child should be getting on average at a given age, the main benefit will be to serve as a discussion point for parents with their healthcare providers about whether the duration of their child’s sleep is perhaps causal for or contributory to whatever malady they may be experiencing. Bottom line: If your child is sleeping outside of the above described ranges, start a conversation with your health care provider!
At Phoenix Children's Hospital, we have two board-certified sleep specialists available to treat your children:
Rupali Drewek, MD, (pediatric pulmonology): (602) 933-0985
Matthew Troester, DO, (pediatric sleep, epilepsy and neurology): (602) 933-0970
Below are links to both the AASM recommendations on pediatric and adult sleep duration. Parents should also make sure they are getting enough sleep too so you can take care of yourself and your busy kiddos!
*Iglowstein I, et al. Pediatrics.2003; 111(2):302-307