Four month sleep regression

How to survive the 4 month sleep regression

Mar 22, 2022
10 min read

In this guide to 4-month sleep regressions:

  • What is a sleep regression?
  • How long does the 4-month sleep regression last?
  • How to deal with the 4-month sleep regression
  • Tips for self-settling
  • How to break sleep associations
  • Sleep Program resources

What is a Sleep Regression?

A sleep regression is a period when a baby or toddler who has been sleeping well suddenly starts waking at night, being difficult to settle and/or skipping naps.

Your baby will go through a number of sleep regressions in the first 2 years of their life, the biggest being the 4-month sleep regression.

This is a natural and normal change for your baby, but it can be a distressing time for parents: a recent study by researchers at Wayne State University published in The Journal of Paediatric Health Care found that the average mother tries more than 7 different strategies to settle their child and reclaim their own sleep.

A key part of moving through the 4-month sleep regression successfully is understanding what causes it, and what’s happening with your baby at this time.

To learn more about when and why this can happen in general, read our full article on sleep regression.

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So, what exactly is the 4 month sleep regression?

It is known as the ‘famous’ 4-month sleep regression because it’s the biggest change in your baby’s sleep that will ever happen. But, we like to not think of it as a regression but more of a maturation of your baby’s neurological development.

Basically, you might have had an amazing sleeping newborn and then suddenly they’ve started waking a lot more in the night and catnapping in the day. Your baby will now start to fully rouse between each sleep cycle, rather than drift between cycles automatically as they did when they were younger.

What happens to sleep cycles during the 4-month sleep regression?

  • Day time cycles change - This is where babies begin to wake fully between each 45-minute sleep cycle in the day.
  • Night time sleep cycles shorten to be 2 hours long and babies stop drifting from one cycle to another so easily.

Your little ones sleep cycles have changed and this means that they will start catnapping more and being very overtired come bedtime in the evening because catnaps are the least restorative type of nap for a baby. This change also marks the point in which learning to self-settle can really benefit your baby’s napping and night-time sleep.

How long does the 4-month sleep regression last?

Now, we hate to break it to you but the 4-month sleep regression is a permanent change to how your baby sleeps and won’t go away until they have learnt to self-settle.

Self-settling is simply your little one's ability to fall asleep without your help. It is definitely something that any baby is capable of doing if everything is lined up right for your bubs, such as their awake times, nap structure and they have a good predictable pattern to their day. You must remove your assistance in the sleep equation to give your baby the chance to put their new sleep powers to the test.

Tips for approaching self-settling:

Like learning to read, self-settling is a skill that doesn't simply develop overnight. It is something completely new for babies and they need a process of coaching, consistency and the chance to learn to do it themselves. Us giving in and continuing to settle them at the first grizzle means we’re denying them the chance to work on this new skill; we’re not doing them any favours in the long run.

  • Encourage good sleep habits
  • A baby who is overtired or under tired will find it really hard to learn to self-settle (take the guesswork out of when your baby actually needs sleep with our Sleep Programs)
  • Consistency is absolutely key - don't give your baby mixed messages by allowing them to self-settle some of the time then settling them other times
  • A dark room, white noise, swaddle (for babies under 5 months) or baby sleeping bag are excellent positive sleep associations which greatly help your baby's chances of learning this new skill
  • A hungry baby won't settle no matter what you do
  • Have high expectations of your little one and work hard to achieve them

How does babies sleep change during this time?

At 4 months, (but sometimes as early as 8 weeks), your little one’s sleep starts to operate like ours as adults, where we go in and out of deep sleep and light sleep, otherwise known as REM. REM sleep is a lighter sleep where we dream and are more likely to be woken if something is different or bothering us in our environment and it’s exactly the same for babies of this age.

Sleep has also become a very conscious thing now for your little one and if they have certain sleep associations such as being rocked, fed or patted to sleep then they will need you to repeat this action every single time they wake between cycles… That’s right, EVERY SINGLE TIME. That’s every 35-45 minutes in the day and 2 hours overnight.

NOTE: Remember not all babies will reach these developmental stages at these exact ages, so if your baby is 3.5 months and starts waking every 2 hours overnight, it's safe to assume they've hit the 4-month regression.

What are sleep associations?

The way we put our babies down to sleep will dictate how they learn to go to sleep; it's all they know. “Sleep associations” are simply cues or behaviours such as rocking, feeding or patting that your baby associates so strongly with going to sleep that they can’t sleep without them.

During the 4 month sleep regression sleep associations start to play a big part in your baby's ability to go to sleep and stay asleep because sleep has now become an active process rather than a reactive process (like when your baby was younger). From this age onwards the way babies are put to sleep at the start of a nap or at bedtime is the method they completely rely on to go to sleep. When your baby then naturally wakes at the end of a sleep cycle, if that same sleep association isn’t there they will not be able to go back to sleep without it. This is why your baby may start napping for only 45 minutes during the day and waking every 2 hours in the night beyond the age of 4-6 months and need your help to go back to sleep.

How to break sleep associations during a regression

There are two types of sleep associations, the baby controlled associations and the parent controlled associations.


These are things that a baby can easily access or use or do themselves to assist them to fall asleep, or things in a baby’s sleep environment that signal it is time for sleep. If your baby is using these things, they will be able to move between sleep cycles on their own, without needing your help. These are:

  • A lovey or comforter
  • Baby sleeping bag
  • Swaddle (in babies younger than 4/5 months)
  • Pacifier (around 7 months babies can replace their own pacifiers in the night)
  • White noise (for babies younger than 12 months)
  • Thumb sucking


These are things that a parent (or caregiver) has to do to get the baby to sleep; things a baby is incapable of replicating themselves. The most common are:

  • Feeding/nursing
  • Rocking
  • Patting or tapping
  • Shushing
  • Holding
  • Replacing a pacifier (for babies younger than 7 months)

The aim here is for your little one to learn to self-settle, and the key to achieving this is to first, make sure your baby's awake times and nap requirements are right for their age, and then by breaking parent controlled sleep associations by reinforcing baby-controlled associations.

What are the signs of the 4-month sleep regression?

The main sign that your little one is going through a regression is that their sleeping pattern dramatically changes. They’ve suddenly gone from sleeping well to not being able to settle for naps and bedtime.

 Other signs to look out for are:

  • Night-waking increases
  • Increased crying and fussiness
  • Missed or shorter naps (Catnapping)
  • Overtired

What causes the 4-month sleep regression?

Nothing necessarily CAUSES regressions, as they are developmental phases that all babies go through, but sleep regressions often get confused with multiple things, like growth spurts and the need for nap transitions. Yes, these can be factors to a change in your little ones sleeping pattern, but don’t confuse them for a regression as sleep regressions are more about your baby’s mental growth rather than their physical growth.

Is it the 4-month sleep regression or something else?

 So, we know that brain development is the main cause of the 4-month sleep regression, but there are a few factors that often get blamed for poor sleep when in fact, it’s actually a sleep regression such as:

  • Teething
  • Growth spurts

Now, there is a common misconception that babies are simply going through a growth spurt, when in fact it is a sleep regression, and although sleep regressions are triggered by normal growth and developmental patterns, they’re not the same as a growth spurt. Growth spurts happen more frequently than sleep regressions. (Phew!)

Do sleep regressions ‘ruin’ the sleep training you have done/doing/ plan to do?

The answer is not at all. Certainly, during a regression it makes it a little more tricky to follow a plan, but ‘sleep training’ is the only way through the big 4-month sleep regression, so we would say the more you’re prepared the better.

Following a schedule and implementing good sleep habits early on will certainly help you down the line and will allow you to recognise when something like a sleep regression is occurring, because you will be able to recognise the changes in your baby’s sleeping habits. And most importantly you will recognise when your baby’s sleep needs have changed due to illness, in which case contact your GP straight away.

How to deal with the 4-month sleep regression

The thing to remember is that the 4-month sleep regression doesn’t go away until your little one has learnt to self-settle, but never fear there are a few ways to deal with this regression in the meantime, see below:

  • First, recognise what is causing your bubba to wake up. If this is a sleep association such as being rocked or patted to sleep then create a plan to wean your little one from that, to help them self-settle. Reinforce baby-controlled associations and slowly break parent-controlled associations - do this in preparation for the 4 month sleep regression.
  • When your little one wakes, allow them to self-settle - rushing in and assisting them straight away is not giving them the chance to practice this new skill!
  • Your baby’s environment plays a huge role in how they sleep, it’s a common misconception that babies don’t like the dark, when actually the darker the room the better - especially at this age as they’re responsive to the light and the slightest change in their environment will trigger them to wake.  As well as a dark room try using white noise, We would suggest using our baby sleep shhh Track or white noise to help your baby transition from light sleep to deep sleep without fully waking up.
  • Stick to your routine - consistency is key! Although the 4-month sleep regression might be difficult to stick to your normal routine, but try your best to stick with it as it will be a lot harder to get back into routine once your little one has come through the regression. Make sure the routine (naps and awake times) are age appropriate.
  • Foster good sleep habits before the regression kicks in such as ditching the pacifier if you find you're having to replace it all night long or use a swaddle in babies under 5 months - this can help them resettle between sleep cycles
  • Create a bedtime routine as it teaches your baby to accept sleep as the final component of the routine. Find out more about the importance of a bedtime routine here.

The 4 month sleep regression is tough, there are no 2 ways about it! It is a rough couple of months as your baby adjusts to the massive changes happening in their brain. Luckily, there are ways through this tricky phase and ways to minimise the sleep impact on your baby and your whole family. The first place to start is with our comprehensive Sleep Programs!  

"I have been following your program now for three weeks and the difference in my little boy who is 5 months old is amazing, we have a structured day with a morning nap and afternoon nap both in his cot and a bedtime of 7pm. And this week he has started to sleep through the night. I feel more relaxed and have time to catch up on things that before I couldn't do as he just catnapped for 20 minutes at a time. Thank you so much you saved my sanity. Xxx" - Vicky

"A week ago my six month old was catnapping for max 20 mins, mostly in our arms and co sleeping at night. She is now following a pattern with 2-3 naps per day, including 2 hours lunchtime and in her cot for day naps and night sleeps! I've gone from getting up every 30-40 mins to resettle to resettling once or twice at night! Thank you Little Ones!" - Amy


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