Is your baby or toddler struggling to link or connect sleep cycles overnight and you have no idea why?
Maybe they’re waking more often than other babies you know of a similar age and you’re feeling like they should be sleeping for longer stretches too.
Or maybe they’re REALLY wakeful – waking every sleep cycle (hourly, or even more often) for some, or all, of the night?
If you’re in either of these situations – you’re in the right place and you’re definitely not alone!
Frequent night waking is by far the most common sleep challenge I help parents with in my work as an evidence-based baby and toddler sleep educator.
Keep reading because I’m going to explain the most likely reasons why little ones struggle to link or connect sleep cycles at night, and what you may be able to do to help your baby or toddler sleep for longer stretches.
Let’s start with a little bit of background info…
Firstly: it’s important to be aware that no-one technically ‘sleeps through the night’
And that’s because every human being sleeps in cycles.
Each sleep cycle is made up of different stages of sleep – younger babies cycle through a combination of ‘quiet’ and ‘active’ sleep, while older babies/toddlers, children and adults cycle through various stages of non-rapid eye movement (NREM) and rapid-eye-movement (REM) sleep [1].
Adult sleep cycles usually range from 70-120 minutes in length, depending on the time of night.
While babies and toddlers have shorter sleep cycles – between 50-60 minutes long on average [1], though research shows they can range anywhere from 30-70 mins [2].
At the end of every sleep cycle we enter into a stage of semi-awakeness and we either stir and transition into the next sleep cycle if all’s well and we’re tired enough; or if we’re not tired enough, or something’s not right (maybe we’re uncomfortable, hungry, thirsty, unsafe, stressed, worried or need to go to the bathroom) we may fully wake up.
Secondly: it’s NORMAL for babies and young children to wake at night
There’s a really good body of evidence that supports this! For example, a study out of Ireland in 2015 found that 84% of 9 month old babies were reported to wake and signal to their parents at night [3]. A study out of Canada in 2018 found that only 57% of 12 month olds were reported to ‘sleep through the night’ (for 8 hours straight) [4]. And a study out of the US in 2019 used actigraphy (electronic monitoring) to measure sleep/wake activity and found that toddlers aged 2.5 years woke on average 4.7 times for greater than 5 minutes each time [5]. Not all of those would have been signalled awakenings, but interesting all the same! Finally, a study out of Finland found that babies aged 3, 6, and 8 months woke on average between 2.2 and 2.5 times a night. So a little over 2 wakes was the average in each of those age groups, with most waking between anywhere from 0 to 5-6 times a night, and a small percentage waking more often than that [6].
So the evidence is very clear it’s more common than not for babies to wake at night and still very common into toddlerhood. So if your little one isn’t linking or connecting all their sleep cycles at night, don’t stress – waking at night is 100% normal!
Side note: if a parent tells you their baby sleeps through the night – either they’ve been sleep trained (in which case they still wake but just don’t signal [7]), they’re in the minority who naturally wake but don’t signal, or they’re telling you a porky pie!
And it’s not just babies and toddlers who wake at night – we also have to remember that it’s very normal for adults and older children to wake.
The difference is, adults and older children can usually solve their own problems and get back to sleep without the help of another person, whereas babies and younger children often need help from a trusted caregiver to tend to their needs and fall back asleep.
Why do babies & toddlers wake at night?
Little ones wake for many reasons at night. The most common include:
To feed
Their tummies are much smaller than older children and adults, and milk – especially breastmilk – is easily digested, so they often need to feed more often for nutrition/hydration – and that can include at night – at least a few times, sometimes a little more if a baby is ‘breastsleeping’ (breastfed and bed sharing).
Very frequent feeding, especially every sleep cycle, can sometimes be a sign of a feeding problem and should be investigated with a healthcare professional, especially if you have concerns. It can also be a sign of low sleep pressure (covered further down this list).
Separation anxiety
Some little ones have a strong need to be close to their parent/caregiver at night, and can become stressed if they can’t sense their caregiver’s presence (hear/smell/touch them) when they wake.
Other stressors
Stressful events or situations (e.g. starting daycare, the arrival of a new sibling) can also affect sleep, so if there’s been a big change in you or your little one’s life recently and it coincides with increased wakefulness, that might be why.
Pain or discomfort
This might be related to temperature (especially being too hot), needing a nappy/diaper change, illnesses (which are super common in the first few years), and – less commonly, but important to consider – are health conditions that cause pain or discomfort. In terms of teething, the jury’s out – research to date hasn’t been able to find a relationship between teething and significant sleep disruption at night [8-11].
Health/developmental conditions
While some health conditions affect sleep as a result of pain/discomfort, others can disrupt functions in the body or brain. If you have any concerns about your little one’s health or development, it’s important to investigate further with a healthcare professional.
Bad dreams / frightened by something (a loud noise, the dark etc.)
These can activate the body’s stress response system and they may need your help to calm down and fall back asleep.
Low sleep pressure (not being tired enough)
While a few wakes at night is usually 100% normal, if a little one’s sleep pressure is too low it can sometimes cause them to sleep lightly and fully wake up at the end of each sleep cycle for some or all of the night.
If your baby or toddler is very wakeful – waking frequently at night – and you’ve ruled out other possible causes, this may be the reason!
Sleep pressure (aka ‘sleep-wake homeostasis’) is one of the two systems in the body that regulates sleep and it’s a measure of how sleepy we feel. It’s actually a chemical called adenosine, which builds up in our brain while we’re awake. The more time we spend awake, the sleepier we feel. And then as we sleep, it reduces again.
To sleep soundly at night, we need to build up enough sleep pressure by bedtime. If we don’t, we can have trouble falling asleep, or struggle to sleep well at night, or both. Pretty logical, right? But the science often gets lost in the sea of baby sleep misinformation.
Many people believe babies and toddlers need a lot of sleep. That they should sleep 7-7 and have long naps. While this is true for some, research shows there’s actually a REALLY wide variation in sleep needs. Babies and toddlers between 6 and 24 months typically have anywhere from 9 to 16 hours of sleep per 24 hours (including naps) and babies under 6 months anywhere from 9 to 18-20 hours [12]. So every little one is different. Some need lots of sleep, others are more efficient sleepers and have lower sleep needs.
Parents often don’t know this and so we encourage long naps and set early bedtimes, thinking it’s necessary. This isn’t a problem if your little one has average-to-high sleep needs, but if they don’t, too much sleep / not enough awake time during the day can make it hard for their sleep pressure to build, and may cause frequent night waking.
Many little ones who experience this just have a short term blip and then return to a restful sleep pattern without much fuss, or perhaps with a few little changes (my FREE Guide: “3 Evidence-Based Changes You Can Make Today To Help Your Little One Sleep Better Without Sleep Training” has some ideas!).
But some – especially those with low sleep needs – are more sensitive.
They can get stuck in a cycle, where after a string of wakeful nights, they catch up on sleep during the day, which reduces sleep pressure, leading to more wakeful nights. Some of these little ones are wakeful every night, while others ride a ‘sleep rollercoaster’ – cycling between strings of okay/good nights (when sleep pressure reaches an adequate level), and strings of wakeful nights (when it doesn’t). If you’re in this place, please know there is a light – it is possible to get them out of this cycle – it’s something I help parents with every day in my Baby Sleep Revolution™ program.
My baby is waking every sleep cycle, what can I do?
The first step is to figure out what’s causing the wakefulness. The list above includes some of the most common possibilities.
The second step is to address the cause/s.
If you need help with this, this article may be worth a read.
And if you’re struggling with a lot of night wakefulness and have been for some time, and through your investigations you decide low sleep pressure is the most likely cause, have a look at my program: Baby Sleep Revolution™. It’s a one-of-a-kind program that has helped so many parents (1000+ to date!) struggling with excessive night wakefulness when literally nothing else has – even other evidence/sleep science-based approaches and solutions!
I developed Baby Sleep Revolution™ because I found that some little ones – especially babies and toddlers with low sleep needs – are more sensitive/prone to wakefulness. They can sleep soundly at night for decent stretches, but need a bit more help – a more precise approach – to ensure their sleep pressure builds to an adequate level by bedtime each night.
The program guides you through a unique, step-by-step process to help you optimise your little one’s sleep pattern so they sleep soundly, for decent stretches, consistently going forward. And you get the rest you need to feel human again, function properly, and make the most of this precious time.
Georgina x
References:
[1] Science of Sleep: What is Sleep?, Harvard Medical School: Division of Sleep Medicine, accessed 12 September 2024, <https://sleep.hms.harvard.edu/education-training/public-education/sleep-and-health-education-program/sleep-health-education-47>
[2] Grigg-Damberger M. M. (2016). The Visual Scoring of Sleep in Infants 0 to 2 Months of Age. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 12(3), 429–445. https://doi.org/10.5664/jcsm.5600
[3] Hughes, A., Gallagher, S., & Hannigan, A. (2015). A Cluster Analysis of Reported Sleeping Patterns of 9-Month Old Infants and the Association with Maternal Health: Results from a Population Based Cohort Study. Maternal and child health journal, 19(8), 1881–1889. https://doi.org/10.1007/s10995-015-1701-6
[4] Pennestri, M. H., Laganière, C., Bouvette-Turcot, A. A., Pokhvisneva, I., Steiner, M., Meaney, M. J., Gaudreau, H., & Mavan Research Team (2018). Uninterrupted Infant Sleep, Development, and Maternal Mood. Pediatrics, 142(6), e20174330. https://doi.org/10.1542/peds.2017-4330
[5] Hoyniak, C. P., Bates, J. E., Staples, A. D., Rudasill, K. M., Molfese, D. L., & Molfese, V. J. (2019). Child Sleep and Socioeconomic Context in the Development of Cognitive Abilities in Early Childhood. Child development, 90(5), 1718–1737. https://doi.org/10.1111/cdev.13042
[6] Paavonen, E. J., Saarenpää-Heikkilä, O., Morales-Munoz, I., Virta, M., Häkälä, N., Pölkki, P., Kylliäinen, A., Karlsson, H., Paunio, T., & Karlsson, L. (2020). Normal sleep development in infants: findings from two large birth cohorts. Sleep medicine, 69, 145–154. https://doi.org/10.1016/j.sleep.2020.01.009
[7] Hall, W. A., Hutton, E., Brant, R. F., Collet, J. P., Gregg, K., Saunders, R., Ipsiroglu, O., Gafni, A., Triolet, K., Tse, L., Bhagat, R., & Wooldridge, J. (2015). A randomized controlled trial of an intervention for infants’ behavioral sleep problems. BMC pediatrics, 15, 181. https://doi.org/10.1186/s12887-015-0492-7
[8] Wake, M., Hesketh, K., & Lucas, J. (2000). Teething and Tooth Eruption in Infants: A Cohort Study. Pediatrics (Evanston), 106(6), 1374–1379. https://doi.org/10.1542/peds.106.6.1374
[9] Owais, A., Zawaideh, F., & Bataineh, O. (2010). Challenging parents’ myths regarding their children’s teething. International Journal of Dental Hygiene, 8(1), 28–34. https://doi.org/10.1111/j.1601-5037.2009.00412.x
[10] Macknin, M. L., Piedmonte, M., Jacobs, J., & Skibinski, C. (2000). Symptoms associated with infant teething: a prospective study. Pediatrics, 105(4 Pt 1), 747–752. https://doi.org/10.1542/peds.105.4.747
[11] Ramos-Jorge, J., Pordeus, I. A., Ramos-Jorge, M. L., & Paiva, S. M. (2011). Prospective longitudinal study of signs and symptoms associated with primary tooth eruption. Pediatrics, 128(3), 471–476. https://doi.org/10.1542/peds.2010-2697
[12] Price, A. M., Brown, J. E., Bittman, M., Wake, M., Quach, J., & Hiscock, H. (2014). Children’s sleep patterns from 0 to 9 years: Australian population longitudinal study. Archives of disease in childhood, 99(2), 119–125. https://doi.org/10.1136/archdischild-2013-304150
