in this post:

what does it mean to sleep through the night?
should parents worry if their baby or toddler isn’t sleeping through the night?
what can parents try if their baby is not sleeping through the night?

It’s probably the most-googled question for all new parents. When will my baby start to sleep through the night? We all want to know when we’ll get a solid night of sleep again, it’s only natural! If only the answer were that simple…

What does it mean to sleep through the night?

First, we should define what “sleep through the night” or “STTN” actually means. None of us truly sleep through the night. We all awaken brieftly between sleep cycles (for adults rougly every 90 min, for babies about every 45-60 min). We may lightly rouse and jump right back into another sleep cycle, not even realizing we’ve been awake. Or we might roll over or adjust the blankets, or get up to go use the bathroom or grab a sip of water. Babies are just like us, except their sleep cycles are slightly shorter. When they wake between sleep cycles, they may fall right back to sleep OR they’ll cue for their caregivers. This might be because they’re hungry, thirsty, wet, cold, or just need some comfort. All of these reasons for waking up and calling out are valid- but when will they stop?

In sleep research, “sleep through the night” for babies is actually defined as a 5-6 or 8 hour stretch. That’s right. There’s no research on infant sleep that defines STTN as 12 hours per night. So you can forget about that magical 7-7 schedule you’ve heard about- it’s great if it happens but it’s not necessary for all babies! Some parents may feel that their baby DOES sleep through the night even though they are getting fed. If a baby sleeps through a couple of feedings per night and goes right back down, you can definitely consider this sleeping through the night. For other parents, those wakes are still disruptive to their own sleep, or it’s taking a while to get their baby back down each time. They would consider STTN as a more solid chunk of hours where their baby isn’t waking up and calling for them.

Whatever your definition, it’s important to know that like any other developmental milestone, babies are all on their own timetable. Some babies start to sleep through the night and wean night feedings on their own from just a couple of months old. Others are still waking up well into toddlerhood and parents have to take a more active weaning approach. There is a huge range for what is “normal” for when a child will sleep through the night. It’s also important to NOT look at STTN as some sort of “finish line.” Sleep is not linear. Even if your newborn sleeps through the night, it isn’t a guarentee it’ll stay that way. There are multiple periods in the first 1-2 years where sleep can really backslide- and it’s no one’s fault! It’s just the way it is. Baby sleep isn’t perfect and we shouldn’t be setting parents up to feel like it’s some sort of important achievement for their baby to finally sleep through the night.

It’s also key to remember the role that temperament plays in all aspects of life, including sleep. Children with more sensitive temperaments may take longer to sleep through independently. This is for a variety of reasons- a more highly reactive sensory system, higher need for things like touch, closeness, reassurance, etc., a lower stress threshold and so on.

I know you probably want some numbers now. We do have some pretty good data from rather large birth cohorts that show average sleep in the first 2 years of life. For the purpose of this blog post we’ll focus on the number of nightwakings, and age at which children generally stop waking up so much at night.

Paavonen, et al 2020 found that sleep quality is highly variable particularly during the first two years of life, but this variability decreased markedly towards the second year. First, sleep latency (the time it takes to fall asleep) decreased by the age of six months, while night-time sleep began to consolidate (meaning longer chunks of uninterrupted sleep) during the second year.

Paavonen et al measured sleep at ages 3, 6, 8, 12, 18 and 24 months in over 1,000 healthy children. They found that “night awakenings were common at all time points. The average number of night awakenings was 2.1-2.5 during the first year but it decreased to an average of 1.1 awakenings per night in 18 month olds and 0.9 in two year olds (Table 2). Moreover, in two year olds, 28.4% of the children still woke up every night or almost every night and 14.9% had at least two night awakenings for which they needed resettling. The ability to self-soothe was relatively uncommon in our samples throughout the follow-up; the highest rate was seen at the age of 18 months, when it reached 50.2%.”

They also found that the range for night wakings is huge- so it’s probably best not to compare your baby with your friend’s babies. For example, the range of night awakenings at eight months went from zero to 21.

In another study of 44 infants at 6 months old, parents on average reported that their infant slept 6 hours consecutively for about 5 nights out of 13. 20.5% of the infants never slept 6 hours consecutively, three (6.8%) met the criterion every night, but most infants (n = 32; 72.7%) showed high variability between the nights. Mothers reported that their infant slept 8 hours consecutively for about 3 nights out of 13. Half of the infants 50.0% never slept 8 hours consecutively, one infant (2.3%) slept 8 h consecutively every night, and twenty-one infants (47.7%) showed high variability. This study measured STTN as just 6 or 8 hours- hardly all night long!

Should parents worry if their baby or toddler isn’t sleeping through the night?

This same study found that there were no detectable impacts on a child’s physical or mental development if they were not able to sleep for these longer consecutive periods as an infant. We need to remember that night awakenings are normal for babies and they do not equate to sleep deprivation. Fragmented sleep is to be expected at least in the first year, and parents need not to worry if their baby doesn’t sleep through the night by age 1 or even 2.

What can parents try if their baby is not sleeping through the night?

To support your baby’s sleep it’s important to learn what we can optimize and what we need to let go of. Sleep is not within our control. We can set ourselves up for success, though! Here is a freebie guide jam-packed with some tips to get more sleep without sleep training. Click below to get the download sent directly to your email.

If you’re struggling with your little one’s sleep or you’re just not sure what’s normal and what’s not, the HSB 0-18 Month Course is your one-stop shop for learning all about biological sleep and feeding plus how to make gentle changes if and when needed. If you’ve got a toddler who is still waking up and needing you at night or getting them to go to bed is getting very difficult, check out the Better Bedtimes Guide.

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