Sleep Regressions

Baby Sleep Regression Ages: what, when, & how to survive them

Nov 16, 2021
11 min read

In this baby sleep regression guide:

  • What is baby sleep regression?
  • Best sleep regression fixes
  • Sleep regression resources
  • Signs of sleep regression
  • Understanding the sleep regression ages:

- The 8 week baby sleep regression
- The 4 month sleep regression
- The 8 month sleep regression
- The 12 - 15 month regression

  • How long do sleep regressions last?

Picture this  - your bubs has gone from being a top napper and/or sleeping through the night, and just when you think you have conquered all of your little ones' sleep woes, you are suddenly faced with constant night waking and non-existent naps. How did this happen!? 

This is known as a sleep regression, and if you’ve found yourself really struggling with the issue, you’re not alone. Research published in the Journal of Pediatric Psychology found that at least one in three mothers experience problems with baby or toddler sleep patterns, and that these can have serious impacts on their daytime mental functioning and mental health.

In short a sleep regression is a period when a baby or toddler who has been sleeping well suddenly starts waking at night and / or skipping naps. They can now be hard to settle for naps and at bedtime. 

Sucks, right?

So, what is a sleep regression?

Basically, babies go through several massive periods in the first 2 years, where they experience mental and physiological change. In some cases, babies have to re-learn sleep skills (like in the four-month sleep regression) due to the parts of their brain responsible for sleep changing and maturing. 

But, although this seems daunting right now, just remember that sleep regressions are signs that your baby’s development is on the right track. The bad news is, yes their sleep takes the brunt of this, but the good news is that your baby is growing and learning new things and are becoming more engaged with their surroundings and that’s definitely something worth celebrating! 

How to survive a baby sleep regression

We know it probably feels like the first 12-18 months of your little one’s life is an endless whirlwind of regressions, but just remember they are natural developmental periods in your baby’s life that are helping them to grow, mature and develop. And yes, it’s going to be tough, but there are plenty of things that you can do to help you and your little one along the way. 

Firstly, breath and realise it won’t last forever.

Apart from the four-month sleep regression, the other regressions are not permanent and can go away in a matter of weeks.

Give your baby the chance to self-settle.

Now this doesn’t mean hard-out sleep training or a crying abandoned baby, instead self-settling simply means your baby is able to fall asleep on their own when they’re ready to (this shift happens during the four-month sleep regression). Try putting your bubs down to sleep in their crib when they’re drowsy, but still awake, this will help your wee one to self-settle and will also break those existing sleep associations.

Encourage good sleep habits early on before the regressions hit. 

This way you won’t have to try and change any deeply ingrained sleep associations down the track. 

Good sleep habits to foster:

  • Make sure the awake times are age-appropriate
  • Sleeping your baby in a totally dark room to allow the release of the sleep hormone melatonin
  • Have a good bedtime routine to follow (check out our article here), which highlights the importance of a bedtime routine)
  • Using white noise to help get your baby to sleep
  • Ditch the dummy/pacifier if you’re having to replace it all night long
  • Allowing your baby to sleep in their crib for their day time naps as they will learn to associate their bed with sleep.

Stick to your routine.

Although sleep regressions make it difficult for you to stick to your schedule, try to keep up with your regular routine as it will make it so much easier to get back to it once the regression is over.

Don’t suffer in silence.

You also have to look after yourself during this time and if that means asking for help from a grandparent, your partner or a friend, then do it. The more help you can get the better. Also, our Sleep Programs can help to regulate your baby’s sleep during this time and you can also join our community in our Little Ones Village, where you can talk to other parents and our sleep consultants for tips around this tricky period.

How is a sleep regression different to a ‘phase’?

Sleep regressions are commonly passed off as a ‘phase’ when in fact, they’re a normal part and sometimes permanent part of your little one’s development that can’t be avoided. 

A phase suggests something that will pass and this may be true for all regressions but one - the famous four-month sleep regression. This regression is certainly not a phase as it is a permanent change in your little one’s sleep. Read our four-month sleep regression article to find out more. 

Many things can cause your wee one to go through a ‘phase’, such as daylight saving causing early morning wakes, learning new skills, sickness and habit wakes.

For example, if there is something disturbing their sleep environment like sunlight, then your baby may go through a bad sleeping phase due to this or if your little one is sick then that can disrupt their sleeping pattern. So, suss out whether their bad sleep is due to an easy-to-fix environmental change or due to sickness before jumping straight to a regression.

How does sleep regression affect sleep cycles? 

Your baby’s sleep cycle changes during the 4 month sleep regression. We would say prior to 3 or 4 months, babies' night-time sleep cycles are 4-6 hours long, but after around 3 months, babies go through a massive development, where their sleep cycles become more organised and pronounced. 

What happens to sleep cycles around the four month mark during this time?

  • 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.

Learn more about self-settling here.

How does a sleep regression affect sleep associations?

Sleep has now become a much more conscious activity for your wee one, so sleep habits are easily formed in babies this age. The way we put babies to sleep begins to dictate how they come to expect going to sleep in this new phase of their development. These are referred to as sleep associations

Sleep associations often develop around periods of big developmental change or nap transitions for example around 8 weeks, at the 3-4 month mark, during the 8 month regression (which is caused by leaps in your baby's physical development) or the 12 month regression/nap transition period. Babies are more difficult to get to sleep during these times because they might be over or under-tired, they are standing or sitting in their crib or their nap needs have changed and a baby in any of these situations won't settle to sleep easily. This can be when you might start rocking or feeding to assist your baby to sleep and if your bubs has come to rely on that method to go to sleep, they will now need you to replicate that every single time they wake between cycles.

What are the signs of a sleep regression?

The main sign that your little one is going through a regression is that their sleeping pattern takes a turn for the worse. Your baby was pro-nap before hitting the 3-4 month mark and all of a sudden you find yourself part of an anti-nap riot. 

Other signs to look out for are: 

  • Your baby isn’t sleeping through things easily like they used to
  • They are overtired as a result of poor naps and lots more night waking.
  • Their daytime naps become shorter/less
  • Fussiness
  • The inability to easily go back to sleep
  • They’re not hungry or sick

Sleep regression stages: at what age do babies go through sleep regressions?

There are five distinct sleep regression ages that most babies and toddlers experience:

  1. 1. As early as 8 weeks - it’s a small blip, but it happens.
  2. 2. At 4 months.
  3. 3. Between 8-10 months.
  4. 4. Between 12 - 15 months.
  5. 5. At two years.

Remember not all babies will reach these developmental stages at these exact ages, so if your baby is for example 3.5 months and has started waking every two hours overnight, it’s safe to assume they've hit the four-month regression.

The 8-week baby sleep regression

This is the magic mark where many babies begin to catnap and start sleeping worse in the day. Their newborn sleepiness has worn off and they've sort of "woken up" so your baby suddenly seems a lot more alert now. What also happens at this point is their maternal melatonin has worn off, so they need to produce their own melatonin in order to settle to sleep easily and sleep well. Melatonin is a sleep hormone that is only produced and released in the dark, so having a super dark room from this age onwards really helps babies link sleep cycles and stay asleep during naps and overnight. If your baby is continuing to catnap past this point, even if you are using blackout blinds, it could be that their nap timings need a bit of tweaking to move them gently away from newborn sleeping patterns. 

The 4-month sleep regression

The first of the big sleep regressions is the biggest change in your baby’s sleep cycle EVER! In fact, as we mentioned it’s a permanent change. Your little one will start to wake fully between each sleep cycle rather than drift between cycles automatically as they did when they were younger. Sleep has now become a very conscious thing for your baby and it takes practise for them to get this new skill right. As we mentioned, this regression WON’T go away until your baby has learnt to self-settle.

The 8-month sleep regression 

At this age, your baby is going through a massive psychological developmental change. They’ll be learning to crawl, pulling up to stand and finding their voice - your baby is a busy bee, this means they want to wake in the night to practise their newfound skills. Basically, at this age babies are distracted by their own amazingness (and rightly so). Don’t worry, unlike the 4-month regression, this one should only last for a couple of weeks on and off.

The 12 - 15 month sleep regression

This sleep regression is less common and is more to do with nap transitioning. At around 12 months your baby might refuse to take 2 naps and a lot of parents assume this means it’s time to transition from 2 naps to 1. For some babies, this could be the case but for others, it can be closer to the 15-month mark. If your baby is alert or a really good sleeper who sleeps past 7 AM, you may find that they’re able to drop to one nap shortly after 12 months, but if your little one is waking earlier in the morning then it will be closer to 15 months. Don’t rush this transition, you’re wee one will be adjusting to this new change and may start waking earlier in the morning or after one sleep cycle at bedtime for a few days. Just like the 8-month regression, this will resolve itself once your baby is comfortably through the nap transition period. 

The 2-year sleep regression  

Just when you thought it was over … well you thought wrong. At this age, your bubs is now a toddler and with that comes independence as they’re going through some developmental milestones that can negatively impact their sleep, like separation anxiety. Again, this regression will pass, but you have to remain strong with your sleep schedule, especially now your toddler has found their voice and can argue like there’s no tomorrow. 

Find out more about the two-year regression.

How long does a sleep regression last? 

Not all sleep regressions last for the same amount of time, so it purely depends on the age of your little one.

Now, we hate to break it to you but the four-month sleep regression is a whole different ball game to the other regressions. Known as the ‘famous’ four-month sleep regression and the biggest change in your baby’s sleep that will ever happen. This is a permanent change to how your baby sleeps and won’t go away until they have learnt to self-settle

Unlike the four-month sleep regression, the other sleep regressions do go away and should only last a few weeks on and off as long as no new sleep habits creep in during this time.

What causes sleep regressions? 

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 a sleep regression or something else?

If your little one has suddenly started showing signs of a sleep regression, it’s a good idea to rule out other potential causes.

Watch our video: 

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!)


Teething usually gets the blame for A LOT of issues surrounding your wee one. My baby’s not feeding … oh it must be teething, my baby’s grumpy...must be teething, my baby isn’t sleeping ...must be teething. But the truth is teething is actually a short-lived nightmare that happens for a day or two and you will know when your little one is teething as you can actually see the tooth emerge from the gum. So, if your little one is waking more than usual and they are around 3-4 months and you can’t see any teeth sprouting, then it’s safe to say they have hit the 4 month sleep regression.

Separation Anxiety 

As your baby gets older, you may recognise that they start to cling to you more or cry when they are left with someone other than you, this is called separation anxiety and this is quite common during the 8 month sleep regression because babies at this age start being able to tell one adult from another and they start to develop the concept of object permanence.

Object Permanence is the understanding that objects continue to exist even when they cannot be perceived (seen, heard, touched, smelled or sensed in any way. In the earlier months of your baby’s life, you may have noticed that your wee one liked to play peek-a-boo, because in their minds once you had disappeared from their line of sight, you vanished and then you re-appeared again (best trick in the book), but for older babies this is no longer the case.

How do sleep regressions coincide with changes to napping/sleeping? 

Some sleep regressions occur around the same time as nap transitions, which usually happen around 6-8 months and 12-15 months. During this time, you may find that your baby is clingier in the day and harder to settle at bedtime. 

  • The 3-2 nap transition happens around 6-8 months old
  • The 2-1 nap transition happens around 12-15 months old

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.

Our Sleep Programs help you to regulate your baby’s sleeping patterns, and we’re not saying it’s going to be smooth sailing because dealing with a regression is darn right tough, but following a routine will help your wee one to adjust to these big changes, allowing them to sail through the regression a lot easier. 

Baby sleep is an ever-changing phenomenon. From infancy to toddlerhood, there will be many things that affect your baby's sleep patterns and some of these are fleeting, like a cooler night, while other things stick around, like the developmental leaps during a regression. Almost everything in your baby's world will have some impact on their sleep, so in a sense, babies regress and progress in their sleep all the time and sleep regressions are simply just part of that process. So, with that in mind just remember you’ve got this!

Surviving sleep regressions: sleep regression resources



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