4 Month Sleep Regression Explained (sometimes 3 and 5 months too)

4 Month Sleep RegressionOver the years, we’ve had countless parents come to us for help with their 4 month old baby’s sleep. Why? Simple… It’s the 4 month sleep regression. This article will explain why “good” sleepers sometimes turn “bad” around the 4 month old mark. This is also known as the 4 month sleep regression. For most babies, the 4 month sleep regression occurs right around the 4 month mark, but for some babies, it happens a bit earlier (around 3 months) or a bit later (around 5 months). Some babies experience the 4 month sleep regression relatively mildly and very briefly. For others, the 4 month sleep regression is a very, very rough phase marked by lots of crying, and that lasts pretty much indefinitely.

4 Month Sleep Regression: How Your Newborn Baby Sleeps In The Early Weeks

Yes, this is an article about the 4 month sleep regression, so we really should be talking about 4 month old babies, right? We will, in just a moment. First, we need to back up to the newborn phase. When a newborn sleeps, she cycles between “active” and “quiet” sleep (also known as REM and non-REM sleep) but does not have the distinctive stages of sleep she will have as she grows older and her brain matures.

We’ll avoid too much technical talk here. (That’s one reason we have this website, so you won’t have to learn the whole history of sleep if you don’t want to – or can’t stay awake to!). If you are interested in knowing more about our biological rhythms and how we sleep, in more detail, I highly recommend the book, Solve Your Child’s Sleep Problems. Newborns spend a lot of their time in deep sleep, which is why it’s hard to wake them up (even to eat!) in those early days. They do startle awake when they cycle into “active” sleep, which is one reason swaddling can be so effective.

The 4 Month Sleep Regression Changes Things: How Your 4 Month Old Baby Sleeps (And Sometimes Your 3 Month Old Baby, or 5 Month Old Baby)

We all go in and out of light and deep sleep. As adults, we might change positions, look at the clock, or re-position our pillow. Up until now, you may have rocked your baby or simply given him a pacifier and he slept for hours without waking up. Well, at 3 or 4 months old, your baby is now sleeping more like an adult. Now when she falls asleep, she does not enter deep sleep right away, and if you lay her down before she is in deep sleep, she is likely to wake up and you will start all over helping her to fall back to sleep again and again.

4 Month Sleep Regression Patterns: First, Your 4 Month Old Baby Enters Deep Sleep…

Initially in the night, your 4 month old will enter deep sleep relatively quickly, within 30 minutes (this changes as we get older). However, as I said, we all cycle in and out of light and deep sleep. A child’s sleep cycle is about 40-50 minutes. So, your baby will briefly awake 40-50 minutes after she has been asleep. To put that in perspective, if you are holding your baby to sleep, you would need to hold her for at least 30 minutes to make sure she’s in deep sleep and then she might wake up 15 minutes later. Sound familiar?

Overall, though, your baby’s deepest sleep is in the early part of the night, so after that first sleep cycle, she might sleep just fine for a few hours. So, you’re golden, right? Just hold her for an hour? Nope!

4 Month Sleep Regression Patterns: How Your 4 Month Old Baby Sleeps The Rest Of The Night…

The technical definition of “sleeping through the night” is 5 hours of continuous sleep (i.e. no feedings) and many babies can/will do this by 2 or 3 months old. The beginning of the night is your baby’s deepest sleep, and after the first 5 hours (if not sooner, depending on just how challenging he is), he will cycle between light and deep sleep, but the deep sleep won’t be as deep as it was at the beginning of the night. This is where the problem of sleep associations really come into play. If your baby needs your help to go to sleep at the beginning of the night, sometime after midnight or so, he will continue to need your help every 1 or 2 sleep cycles (that means every 40 to 90 minutes, or as I often hear: every 1-2 hours).

Between 4-6 a.m., approximately, is the lightest sleep of the whole night (parents’ complaints alone make this true, in my experience, aside from my reading). In the very early morning hours (about 30 minutes to an hour before waking up), he will again go into the very deep sleep.

Although babies commonly wake up early, be sure it is truly their waking up time and not just this lighter sleep and that they are having trouble sleeping. You might notice they want a “nap” just 30 or so minutes after “waking up”. What you experienced was a night waking, not starting the day.

4 Month Sleep Regression Symptoms

Many parents want to know what the 4 month sleep regression looks like. That will vary from baby to baby, of course, but here is a short list of 4 month sleep regression signs:

  • Changes in appetite (baby may eat more or less than usual)
  • Lots of night wakings (these will seem out of the ordinary, especially if your baby had been sleeping longer stretches recently)
  • Increased crying and fussiness (often, the fussiness will be the inconsolable kind, and nothing you do to comfort your baby will work as well as it usually does)
  • Missed naps and/or shorter naps


4 Month Sleep Regression Explained

As we’ve established, all babies go through these changes in their sleep patterns. However, how your baby reacts to these changes will depend on unique factors. Some babies experience a week or two of fussy, interrupted sleep, and then go back to sleeping soundly at night and taking restorative naps. Other babies, however, are thrown all out of whack by the 4 month sleep regression. They go through weeks and weeks (sometimes even months) of lots of night wakings and missed naps. These babies (and their poor parents!) are hit hard by the 4 month sleep regression and exhibit a lot of the symptoms mentioned above.

If the 4 month sleep regression is a truly bad sleep regression for your baby – how can you cope? Well, we generally advise parents to get to the root of why the 4 month sleep regression is causing disruptions. Usually, negative sleep associations are to blame. Babies who have become accustomed to being rocked, fed, and/or held to sleep continue to need their sleep associations. Now that their sleep patterns have changed, they need them all. Night. Long. Of course, mom and dad can’t sustain all that rocking and holding in the middle of the night. Soon the whole family is exhausted and overwhelmed.

What’s a Parent to Do?

In general, I’d recommend waiting a few weeks, to see if your 4 month old baby’s sleep improves. If it doesn’t, then it may be time to make changes. Work on weaning your 4 month old from his sleep associations. You might also want to work on establishing a gentle 4 month old baby schedule. I would urge you not to wait indefinitely. I talk to parents of 12 month olds and even 3-5 year olds who are still waiting for their “baby” to grow out of their sleep problems.

For more tips on how to cope with and solve your baby’s 4 month sleep regression problems, read our other 4 month sleep regression article: The 4 Month Sleep Regression: What It Is and How To Fix It.

CaseStudyThumbnailWant more information about how to help your 4 month old sleep well? Check out our (VIP Exclusive) detailed case study about Nadia, Brad, and their 4 month old, Abigail.

Read how they helped Abigail learn to sleep longer stretches at night and take better naps. You’ll also learn how they helped to change sleep associations that were keeping her awake! Not a VIP Yet? No problem. Join our VIP Members Area and access the study instantly. You’ll also enjoy TONS of other VIP resources!

Download our Detailed 4 Month Sleep Regression PDF FREE!

Download the 4 Month Sleep Regression PDF Here. You are free to print and/or share this document, as long as the author bio stays intact, and no changes are made.

The Baby Sleep Site® is a participant in the Amazon Services LLC Associates Program and other product affiliate programs. If you click on a product link and make a purchase, The Baby Sleep Site® may (but not always) receive a small commission from the company selling the product, but will not affect your purchase price. We only recommend products that we believe are quality products and are good for our readers.

Holistic Sleep Solutions from The Baby Sleep Site®

e-Book bundles

Do-It-Yourself: Just getting started with your research but you want to stop Googling? Choose from any of our e-Book bundles for practical advice you can put to use TODAY!  

Become a VIP Member

Do-It-Mostly-Yourself: Would you like to continue learning with the option of chatting with a sleep consultant? We have a perfect solution! Become a VIP Member for access to all of our premium content, “ask the author,” audio courses, live weekly chat, and more!

Get a Personalized Sleep Plan

Work With a Sleep Expert: Tap into over a decade of experience with thousands of families before you! Get a Personalized Sleep Plan® just for your unique situation, get guidance and answers to all your “what if?” questions while you work through your plan, and benefit from expert support along the way. We can’t tell you how many times we’ve heard “I wish I had done this sooner!” Not sure? Read these stories from well-rested parents.

Don’t lose another wink of sleep — GET STARTED TODAY with our gentler, kinder approach to healthy sleep!

Since starting in 2008, we’ve gained over 10,000 comments on our blog!

At this time, we’ve turned the comment sections off. We would, of course, love to hear from you! For help with your specific sleep problems, please learn more about our DIY resources or our sleep consultation services. Or, consider emailing us for a fast and helpful response!

128 thoughts on “4 Month Sleep Regression Explained (sometimes 3 and 5 months too)”

  1. Hello,

    Please i need some help! My baby is 5 months old and from a week its been such a struggle to put her down to sleep at night. I fed her and she falls asleep in my hands , i keep her for 10-15min and when i try to put her on the crib she wakes up and starts crying and its just a nightmare. sometimes she cries for 2 hours and at the end she is exhausted and she wants to fall asleep but she she just fights it so i have to give her water or a little more milk so she can fall asleep. She wakes up 2 times at night and since last night she start fighting the sleep during the night as well. She is a formula fed baby. I want to say that since the second week of her life she has been on a schedule meaning 8pm bath, massage, 8:20-8:30 last feeding and crib time , 9pm she is out and its been like that till last week! The day naps are a little hard for us but she sleeps 2-3h during the day either in the stroller or if i put her to sleep. She hates pacifiers, ive tried over 10 brands. Ive tried putting her down at night and leaving the room but she doesnt cry , she screams, its brutal so i dont think thats an option for us! Is she already spoiled? Please help!

    • Hi @Jenny – Thank you for writing! I am sorry that sleep has been so tough for you and your family! We understand, and you are not alone! It does not sound like your sweet little girl is spoiled, but that she just does not know how to fall asleep on her own, and back to sleep on her own quite yet. You can help her learn this, and we can help! As you’ve read in this article, this age can be a difficult one for many babies!
      If you would like personalized help to work through this, please consider our Personalized Sleep Consultation packages or our selection of e-Books. If you choose to purchase a consultation package, one of our trained expert sleep consultants will craft a Personalized Sleep Plan for you and your daughter, based on both your unique family history and on our own experience working with thousands of parents from around the world. Then, your consultant will help you implement the plan at home, and will answer any follow-up questions you may have. The consultant will also make changes to the plan as necessary. You can read about all of our sleep consultation packages and purchase directly online here:
      And, you can read about our Do It (Mostly) Yourself options here, if you don’t think you want or need expert help:
      Good luck Jenny! And please contact us if you would like more info at any time!

  2. Hi there,
    I enjoyed reading your article, but out of all the helpful info I didn’t find it with any advise for breastfed babies vs.formula babies. My friends baby has been sleeping through the night since she was 3 months old, no 4mo old regression that I am aware of, but is formula fed. On the other hand I have been breastfeeding since day 1 and havent stopped, and now have a 4mo old, but won’t sleep more than 3-4 hours at a time during the night. Now it’s getting worse and less a less sleep, every time I lay him down he instantly wakes up, or will kick himself awake. I refuse to give my baby formula simply because I know how much better breastfeeding is for him, but I’m at my wits end and am willing to try anything to get him to sleep more/longer. Any ideas please???
    -Tired mommy of 3

    • Hi @Lydia, thanks for writing to us. I’m sorry you’ve been struggling with your little one’s sleep! I know how difficult it is as a mom to struggle with comparing ourselves and our babies to others, but try your best not to! Some babies can sleep through the night that early, but the average baby doesn’t, regardless of formula versus breastmilk. Here is a link to a sample schedule we have for a 4 month old that offers a breastfeeding schedule and a formula fed baby schedule you can refer to and make sure your baby is getting all he needs in a 24 hour period: https://www.babysleepsite.com/schedules/4-month-old-schedule/
      Additionally this is the age where babies can start to develop sleep associations and I know (as a EBF mom myself) that is is super easy to create a sleep association to the breast for our babies. We have lots of articles on sleep associations and how to work through teaching your child to sleep without them, so click around on our articles and I’m sure you’ll find tons of helpful information.
      Additionally, if you want more help that is specific to your exact situation, we’d love to help with that as well. In addition to our blog we have a variety of exclusive content – ebooks, teleseminars, personalized consulting with a sleep consultant, and those are all available to you should you be interested. Please just contact us directly at [email protected] and we can help explain those options in greater detail for you so you can get through this challenging time. Hang in there! I’m having my 3rd soon too, and I’m a little nervous about how crazy that’s going to be, but I’m sure you’re doing amazing and will get in the swing of things soon (especially when you start getting more sleep)!

  3. Hi my daughter is 4 month and she cries screaming crazy around 4 to 5am in so sleep deprived going nuts a little..I feed her burp her bath and then sleep but she won’t . I’m so tired I dont know what to do anymore please help.

    • Hi @Yer, I’m so sorry to hear you’re struggling so much with your 4 month old’s sleep! That can be a very challenging age for sleep for babies, so know you are not alone. We would love to help. First off, here is a link to download a free guide which goes through tips to help you get your baby sleeping through the night (or at least having an appropriate amount of wake ups – at 4 months we’d say 1-3 wake ups for a feeding is totally normal but anything beyond that is a problem, as well as the fact your baby is up and so upset would also be something to address of course): https://www.babysleepsite.com/sleep-through-night-free-ebook/
      If you find you’re at your wits end and want more specific help than a free guide can provide, we’d love to work with you through one of our other services. We have a team of highly trained sleep consultants who would love to help walk through this with you and troubleshoot the issues you are coming, or future things that come up as your baby continues to grow and change over the next year. Here is a link to the services we offer: https://www.babysleepsite.com/baby-toddler-sleep-consulting-services/
      If you have questions about specific things, please feel free to contact us directly at [email protected] and we can help you more from there. I hope this helps!

  4. My 16 week old self settles to sleep, usually with a bit of crying as shes overtired by the end of the day. However because of the catnaps/fighting sleep all day no matter when I put her down, she has early morning wakings around 4/5am and wakes up screaming. I usually feed her and she dozes for another 30-40minutes then wakes up again. But she is still cranky. I dont know how to help her or when will she grow out of this??

    • @Lidija – Thank you for reading and for sharing with us. Early waking can be quite a challenge to figure out, and, unfortunately, not all babies grow out of it. You haven’t said how long this has been going on but, if it’s been any length of time, figuring out why she’s waking early (inside/outside environment, too late/early of a bedtime, hunger, sleep associations, etc.) would be key. If you haven’t tried keeping a sleep log for a couple of weeks, this could be a good first step. We give a quick tip on logging sleep here: https://www.babysleepsite.com/sleep-quick-tips/quick-tip-logging-sleep/ Please let us know if we can be of any further help, Lidija. Hang in there!

  5. Hi,
    My baby just turn 4 month this week and for the last 2 weeks he has been waking up every hour. This week he doesn’t want to be put down on his crib he wants to be held while he sleeps. As soon as I put him down he starts crying. Am I supposed to hold him while sleeping until the regression is over? Or do I keep picking him up and putting him down?
    Please help!

    • Hi Marcia,
      Thank you for writing to us. I am sorry that sleep has become such a struggle! The 4 month sleep regression can be brutal. We’ve all been there! Keep up the hard work and hang in there! Since the way your baby sleeps is now changing, you may find that he does not easily “outgrow” this and may need help learning how to sleep better, if you do not want to continue holding him for sleep times. Some babies “outgrow” this stage, but others do not. If you find that things do not smooth out and you would like more help, I would recommend that you consider our e-Book, The 3 Step System to Help Your Baby Sleep.
      The 3-Step System e-Book is the most popular e-Book on our site. Written specifically for parents whose babies are up to 12 months of age, this book is designed to give you the information you need to get your baby sleeping soundly. Written in a straightforward, easy-to-read format, this book will answer all of your baby sleep questions.
      You can find and order the book directly online here: https://www.babysleepsite.com/3-step-system/
      Please let us know if you have any questions! Good luck and hang in there!

  6. Hi There,

    I have some experience from my now 2 year old daughter, but of course my son is a different person and we are having a different experience.

    He is now 18 weeks old. (4 Months) He started sleeping through the night on his own at 8 weeks and mostly did until about 3 weeks ago. He started waking once, maybe twice and more recently – only some nights – he has started waking every 30m-2 hours through the night.

    I have been trying to ensure he is getting in his calories (BM) although he is distracted during the day and ensuring he is napping when tired although his naps have become shorter.

    My first questions is: Will he develop sleep associations by nursing at night to survive this regression? I have tried shushing/ bouncing then nursing back to sleep and only sometimes can I get away without nursing.

    Second question: How long do I continue with the current sleep aids before recognizing the regression is over? You wrote in the article to continue using current aids to get through the phase, but how do you know when it’s over? I know he was able to sleep through the night so I am praying he will go back to doing that soon without any effort on my part, but I don’t want to create sleep associations in the meantime.

    He woke every 30-90 minutes 3 nights ago, only woke once two nights ago and 3 times last night.

    • Hi @Jackie – Thank you for writing to us and for using The Baby Sleep Site as a resource for sleep! It sure sounds like your family is right in the thick of the 4 month sleep regression! I’m sorry to hear this, and you are certainly not alone! We would love to help! As you have read, this age can be a difficult one for many babies, since their sleep is permanently changing from a “newborn’s” sleep, and this often leads to more frequent wake ups at night and disrupted naps. Some babies will come through this and be able to sleep well again, but many others, since their sleep has changed, will need more help to learn or re-learn that they can sleep well again! Feel free to continue to work on helping him back to sleep without nursing, even if it is only successful part of the time, you will get there! Basically, you will want to give him the minimum amount of support needed to get him through. If things do not improve within a feww weeks, you may need to take action and help him learn to fall back to sleep/to sleep on his own.

      If you find that things do not smooth out, and you would like personalized help to work through this, we would be happy to help! Please consider our Personalized Sleep Consultation packages or our selection of e-Books. You can read about all of our sleep consultation packages and purchase directly online here:
      And, you can also read about our Do It (Mostly) Yourself options here, if you don’t think you need expert help:
      I do hope that things smooth out quickly!! Good luck Jackie!!

  7. My baby sleeps for 14 hours every night. Once or twice a month she will wake up for a bottle then go right back to sleep. I dont rock her or anything. At night I put her in her bed and she knows its time to sleep and so she does. Shes almost 6 months. Can i expect this behavior to continue?

    • Hi @Happymom, wow amazing! As babies are ever changing I can’t give you a certain answer, but it sounds like she knows how to go to sleep on her own which is great! If there are ever hiccups along the way, just stay consistent to her routine and hopefully you smooth through any teething or developmental leaps that may try to disrupt the sleep. 🙂

  8. My LO is 3 months 15 days. Our usual routine is wake + feed + play (1-1.5hrs) then nap (1-1.5hrs). However recently he has been taking cat naps of 30-40 mins. Sometimes he can stay awake for two feeds. When it comes to bedtime around 8-9pm, he will wake up after half an hour. Then he will start to fuss, cry and refuse to go to sleep until about 1-2 hours later. And he will wake up every 3-4 hours at night for feeding. Does this consider 4 mths sleep regression? How can I reset back his schedule? It seems like his schedule is all over and I don’t know where to start troubleshooting.

    • Hi @Keeli – Thank you for writing to us and for using The Baby Sleep Site as a resource for sleep! I’m sorry to hear that sleep has been rough for your three month old. We would love to help you through this. As the article stated, this age (around 4 months) can be a difficult one for many babies, since their sleep is permanently changing from a “newborn’s” sleep, and this often leads to more frequent wake ups at night and disrupted naps as they start this sleep regression. It sounds like you have a few issues, with the short naps, night waking, and that long awake time in the night. We can help with this, but would need to really have one of our expert sleep consultants take a good look at his sleep history and overall schedule, as well as any sleep logs that you might have. This would give your consultant the “whole picture,” and allow for her to help by creating a Plan just for you. : )
      please check out our sleep consultation packages here:
      And please feel free to contact us if you have any questions! And hang in there Keeli!!

  9. Hi.
    My baby is 3 mnths old. He usually sleeps well at night. Usually 8pm to 7 am with 2 feedings. But he doesn’t take nap in the day. May b 15 min/ 10 min/ 5 min in a nap. Then wakes up but feels like he wants to sleep more and cries to go back but can’t and all day crying to sleep. So frustrated

    • @Rezwana Hossain – Thank you for writing to us! I am so sorry you’ve been struggling with your 3 month old’s naps, I know how frustrating that can be. We have a link to a free guide with some nap tips that you are welcome to sign up to download here: https://www.babysleepsite.com/free-baby-nap-guide/
      If you are still struggling and your baby is not napping for you, please let us know, we would love to help. We have an incredible team of sleep consultants who would be happy to help you figure out the issue and create a schedule for your baby that you all feel good about. Here is a link with more information if you are interested: https://www.babysleepsite.com/baby-toddler-sleep-consulting-services/
      Hang in there!

  10. Please i need your help my baby is 4 month now and he statrt sleeping at 1 p.m and wake up in 7 p.m. He wake up only to drink milk.in the night he take a nap every one or two hours
    How i can move her long sleep to the night i’m so exhausted please help me

Comments are closed.

FREE Guide: Five Ways To Help Your Child Sleep Through the Night

Join over 450,000 parents around the world & sign up today to receive the guide and our Baby Sleep Newsletter absolutely FREE!