Around 4 months old, you may start noticing significant changes in your baby’s sleep patterns. Just as you thought you had settled into a rhythm with your little ones sleep, suddenly it seems to go haywire! If this situation sounds familiar, your baby might be going through what’s commonly known as the 4 month sleep regression.
But, don’t panic! This guide to the 4 month sleep regression is here to help you understand what’s happening with your baby’s sleep and guide you through this developmental phase.
The early months of parenting can be both magical & challenging…
That’s why we designed our ‘Early Days & Foundations of Sleep’ course – to support parents just like you. Expert guidance, insights and strategies to confidently navigate your new world of parenting and lay foundations for great sleep!

Let's dive into what THIS GUIDE COVERS:
What is the 4 month sleep regression?
Why is there a sleep regression at 4 months old?
When does the 4 month sleep regression start?
What are the signs of the 4 month sleep regression?
How long does the 4 month sleep regression last?
What else could be affecting sleep around 4 months?
What is the 4 month sleep regression?
So, what exactly is the 4 month sleep regression? It refers to a developmental period, around 4 months of age, when babies experience a permanent change in their sleep structure as their sleep cycles mature.
This can be a noticeable turning point in sleep, as even babies who previously slept well may start to resist falling asleep, take shorter naps, become harder to settle, and wake up more frequently during the night.
Why is there a sleep regression at 4 months old?
But why does this regression happen at 4 months old? Well, it’s linked to your baby’s neurodevelopment.
The 4 month sleep regression is actually a progression (even if it feels like a big step backwards!), marking the maturation of your baby’s sleep cycles to more closely resemble those of adults.
Gone are the simple awake/asleep cycles of newborns, replaced by more complex sleep phases that serve different purposes like cell growth, memory consolidation, energy restoration, and overall physical and mental development.
Once this transition in sleep occurs, both babies and adults naturally stir or partially wake between sleep cycles. How your baby falls asleep and settles back to sleep when they wake up can influence how much of an impact the 4 month regression has on their sleep.
When does the 4 month sleep regression start?
The 4 month sleep regression typically starts around, you guessed it, the four month mark. However, every baby is unique, and some may experience it a bit earlier or later.
Generally, it occurs between 3-5 months of age. If your baby was born prematurely, you can use their adjusted age as a reference for when this sleep change might happen.
Some babies breeze through this regression with barely any noticeable change in their sleep, whilst others might show much more obvious signs that their sleep has changed and need a bit more help getting back on track.

What are the signs of the 4 month sleep regression?
Now, let’s talk about the signs of the 4-month sleep regression. While occasional variations in sleep are normal, if you notice the following signs, it’s highly likely that your baby is going through the regression:
Fighting sleep:
Your once-easy-to-settle baby suddenly resists sleep, and your usual techniques no longer work like they used to. Rocking or feeding them to sleep becomes less effective, and those peaceful crib or Moses basket naps seem like a distant memory.
Shorter naps:
Your baby’s daytime naps become shorter, often limited to just one sleep cycle (around 35-45 minutes) or less. As a result, they may become fussier and more tired throughout the day.
More frequent night waking:
Around 4 months old, your baby may start waking up more frequently during the night. This can be attributed to changes in their sleep cycles and their growing awareness of their surroundings. They may wake up crying and have difficulty falling back asleep, whether with or without your help.
You might find yourself trying more night feeds, doing the ‘dummy run’* or feeling like you’re constantly rocking and pacing the room to get them back to sleep through the night.
* ‘dummy run’ = running to return their dummy or pacifier each time they stir or wake!
How long does the 4 month sleep regression last?
Unlike other so-called ‘regressions’ and periods of disturbed sleep, the 4 month sleep regression is a permanent change to your baby’s sleep.
Just because it’s permanent doesn’t mean that sleep will feel like a struggle forever!
For some babies, especially those who can fall asleep independently without much external support, the 4 month sleep regression can be a smooth transition that they breeze through with minimal disruption to their sleep.
But for others, this change in their sleep structure can cause broken sleep, short naps, and difficulties falling asleep.
If your little one is struggling, they might benefit from some support in practicing how to fall asleep and settle themselves back to sleep when they naturally wake up between sleep cycles.
Fear not! You can help your baby get their sleep back on track and support them in practicing falling asleep in a different way.
Our ‘Early Days & the Foundations of Sleep’ course offers practical tips and strategies to help your baby get their sleep back on track and create a great routine to suit their needs. If you baby is a little older (around 5.5 months or more), then our ‘Sleep Success: 6-9 month’ course is perfect for you.
What else could be affecting sleep around 4 months?
The 4 month sleep regression can definitely throw a wrench in your baby’s sleep routine, but there are other developmental milestones happening around the 4 month mark that can also lead to some sleep disruption.
You see, sleep regressions, and temporary disruptions to sleep, can happen at any age and can be different for each baby. So, it’s not unusual for sleep to go a little haywire during periods of change and development.
These are some of the exciting milestones your little one might be experiencing around 4 months
- Babbling and experimenting with making sounds – they might even start to mimic your facial expressions and sounds!
- Rolling over like a pro – or giving it a try!
- They may start teething.
- Hand-eye coordination is developing.
- Improved focus on objects and people from a distance, plus tracking moving objects.
- Overall sleep needs change, meaning they’ll need less sleep over a 24 hour period.
- Possible growth spurt – they might want to feed longer or more frequently.
- Increased awareness of their surroundings, which may lead to more distraction from light and noise during sleep times.

9 tips to survive the 4 month sleep regression:
Now that you know what your little one is going through, let’s dive into some survival tips for the 4 month sleep regression:
#1: Establish a predictable, consistent routine.
Having a consistent bedtime routine can work wonders in helping your baby wind down and recognize that it’s time for sleep.
It doesn’t have to be complicated – a series of simple steps leading up to bedtime (and a shorter version for nap time) can be all that is needed.
You can also start establishing a more predictable routine for naps and bedtime around this age. There is no need for strict timings or constant clock-watching. You can start by simply aim to start and end the day around the same time each day to give your routine some structure.
#2: Create an optimal sleep environment.
Some babies may happily nap with lots of light and activity around them, while others may need a darker and quieter space – especially as they become more aware of their surroundings and stir between sleep cycles.
You can experiment with white noise to mask everyday sounds and create a more soothing atmosphere. Consider making the room darker for naps and nighttime sleep. If you’re on the move, using a sling for naps or a cover like SnoozeShade for the stroller can help your little one settle and enjoy longer naps.
#3: Reflect on how your baby is falling asleep.
For some families, the 4 month sleep regression can be a great time for families to take a moment and think about how they are helping their baby fall asleep and if it’s sustainable for them.
Rocking, feeding, carrying, swaying, and bouncing to sleep are all common ways we assist our little ones in drifting off (and there’s no need to change anything if you don’t want to). However, if these approaches start to feel less effective or sustainable, it may be time to explore new ways for your baby to fall asleep.
#4: Practice independent sleep
Around the age of 4-5 months can be a great time for your baby to start or continue practising falling asleep independently for naps and bedtime in their crib or cot.
For many families, supporting their baby to fall asleep on their own can unlock a more predictable routine and lead to more peaceful nights.
Remember, we’re not talking about “sleep training” at this stage. Instead, we’re gently guiding our baby to develop their sleep skills.
It’s can be a gradual process of helping them to learn to fall asleep in a new way and return to sleep independently. You might begin with one nap a day or focus on bedtime.
After your baby has been fed, winded, is comfortable, and has enjoyed some winding down and cuddle time with you, try placing them in their cot while they’re still awake and on their back. You might be surprised by the results!
#5: Embrace natural light and fresh air
Fresh air and daylight, at the right times, can work wonders for both babies and us! Make sure to spend time outside and soak in the natural light during the day.
Daylight helps regulate circadian rhythms, assisting your baby in distinguishing between day and night. Encourage plenty of natural light and activity during the day, while keeping evenings and nights calmer, darker and peaceful.
#6: Practice new skills during the day
Allow your baby the opportunity to explore and practice their newfound skills during the day.
Set aside time for them to roll, engage in tummy time, and work on holding their head up on a playmat. Place toys within their reach, and when they make sounds, repeat them back and engage in conversation. Point out items that catch their interest and describe what they see.
#7: Don't be afraid to give them space to settle.
When your baby stirs between sleep cycles or takes a little longer to fall asleep in their crib, cot or Moses basket, it’s normal to feel tempted to intervene immediately.
They may seem wide awake or starting to wake up, but they might just be naturally readjusting as they fall asleep or settle back to sleep. While we need to be present and tuned into what they need, sometimes it helps to hold back and give them a little time and space to see if they can fall asleep or return to sleep on their own.
#8: A little patience.
It can take time and practice for babies to get used to a new way of sleeping. Finding a day time rhythm and approach to sleep that suits their current needs can take some experimenting and patience.
#9: Accept help and ask for support when needed.
It’s easy to forget about our own needs in the midst of it all. Take advantage of any help that’s offered, and don’t hesitate to ask for assistance when you need it. Whenever possible, prioritize getting an early night’s sleep and sneaking in some naps – every bit of sleep counts!
We get how challenging it can be to fall asleep or get back to sleep when we’ve been woken in the night. Sometimes we lie there, anxiously waiting for the next disturbance, and miss out on precious opportunities for additional rest! That’s why we have a fantastic course for parents that can help you sleep better too. It’s packed with practical advice on improving our own sleep, falling asleep more easily and returning to sleep after we are woken in the night.
Our baby sleep courses cover all of these areas in detail, giving you a step-by-step guide to truly understand your baby’s sleep and create a plan to help you achieve predictable naps and restful nights in a way that suits your baby. Just choose the course that is closest to your baby’s age below, and you could all be sleeping much better very soon!
Sleep Course: 0-5 Months

The perfect guide for newborn to 5 months
Gentle solutions for settling & guidance towards an end goal of a settled night’s sleep, whilst understanding your own baby’s needs.
Sleep Course: 6-9 Months

Ideal for babies aged 5.5 months and over
Covering everything from the science of sleep to how to create a great daily routine. Shape predictable daytime naps and restful nights.
4 month sleep regression FAQ
Q: How can I prepare for the 4 month sleep regression?
A: You can introduce to have a predictable consistent routine with your baby whenever you are ready.
Create clear signals for naptime and bedtime, and give your day a simple structure that suits their current sleep needs. Gradually practice settling your baby to sleep, allowing them to try falling asleep when it feels right for both of you.
Don’t worry! The 4 month sleep regression is a natural part of your baby’s development. If sleep goes haywire, remember that you can always make adjustments to get back on track.
Q: Is the 4 month sleep regression real?
A: Absolutely! The 4 month sleep regression is no myth—it’s a permanent change to your baby’s sleep patterns.
Q: How do I avoid the 4 month sleep regression?
A: You can’t avoid the natural changes to your baby’s sleep cycles during the 4 month sleep regression. However, there’s no need to fear this developmental phase.
You can establish a predictable and consistent routine, offering your baby opportunities to practice falling asleep on their own before they reach 4 months of age or at any point in time later when you are ready.
Q: We're past the 4 month sleep regression and sleep is still a mess, what can I do?
A: We know many families reach the 6 month mark (and older), only to find that their baby’s sleep is still in chaos since the 4 month sleep regression.
The good news is that it’s never too late to work on improving sleep.
Our 6-9 month sleep course covers everything you need to know about your baby’s sleep, from sleep associations and creating a sleep-friendly environment to finding a daily routine that suits them. We even provide a range of methods for settling your baby to sleep, allowing you to choose what works best for you and your little one.