May 12, 2020

All You Need to Know About the Four-Month Regression

Babies, Newborns

Did the mere title of this post make the hairs on the back of your neck stand straight up? Those who have heard of the four-month regression dread those words.

My now toddler was a pretty good sleeper as a newborn. However, around that four-month mark is when her sleep went downhill, and I joke that “it lasted until she was 10 months old.”

It did not, in fact, last until she was 10 months old, but her dependent sleep habits that grew even more dependent at four months lasted that long.

No matter how many times she would wake in the night, I would immediately nurse her and then burp/rock her to ensure she was fast asleep, and then put her down. She often stayed asleep upon being laid down, but I occasionally had to repeat the same process a few times until she stayed asleep.

That then became our pattern and remained so until she turned 10 months old and we had had enough.

So in this post, I am going to share with you what I wish I had known about the four-month sleep regression a few years ago, including:

  • What the four-month sleep regression is and why it happens
  • Signs your baby is experiencing the four-month regression
  • How long the four-month sleep regression usually lasts
  • How to help your baby get through the four-month regression

And more! So let’s dive in…

What is the four-month sleep regression?

The four-month sleep regression is an actual, physical change that happens to your baby’s sleep. Newborn babies’ sleep is underdeveloped, meaning they only have two sleep cycles – they flip flop between a deep sleep and a light sleep.

Around four months of age (it might be a little before or a little after), babies’ sleep starts transitioning into more developed, adult-like sleep cycles. Rather than just having two sleep cycles, they now have four stages of sleep per sleep cycle.

This is a big change for babies, as more adult-like sleep cycles means more time in a lighter stage of sleep, which babies aren’t used to.

(If you want to dig a little more deeply into these different stages of sleep, head here!)

What does the four-month sleep regression look like?

Because babies are now adjusting to more time in a lighter stage of sleep, it’s like they keep “falling out of sleep” and need help getting back. So the most common signs of the four-month regression are an uptick in night wakings and short naps.

The four-month regression can also be characterized by what feels like a never-ending bedtime. You rock your baby or feed your baby to sleep per usual, you lay them down, and the moment they touch the crib, their little eyes pop open and you have to start all over again.

That’s because these adult-like cycles also mean the whole “drowsy but awake” strategy that often works to help get newborns to sleep no longer works! Now “drowsy” is essentially the first step of sleep, as it is for you and me.

How long does the four-month regression typically last?

As a general rule of thumb, sleep regressions typically last around two weeks, and this is true of the four-month sleep regression, too – It might take a solid two weeks or so before your baby’s sleep cycles have fully adjusted.

The reason many families think this regression “lasts forever” is because we enter survival mode – we do whatever we can to just get our baby back to sleep so we can get back to sleep. For me, that meant each time my baby woke up, I nursed her and rocked her back to sleep.

Did she really go from just needing one night feed to needing four or five or six? No! But that was the quickest and easiest way for me to get her back to sleep, so that’s what we did.

The problem was, my baby quickly learned that the only way to get back to sleep in the middle of the night was to nurse. So even after the technical “two weeks” were up, nothing changed – she was now in the habit of stirring, then fully waking, then nursing back to sleep, repeat. So that pattern continued until she was 10 months old and something just had to change.

Tips to Help Your Baby Get Through the Four-Month Regression

Wait Before Responding

If you hear your baby wake up in the night, try to wait around 10 minutes before responding. Remember how I mentioned you’re little one might be “falling out of sleep”? We always want to give them a chance to fall back into the next sleep cycle before going in there and helping.

Yes, your presence will certainly be comforting, but they could also become more stimulated with you in there, so we always want to give them a chance to fall back asleep first. If you’ve waited and they haven’t calmed in that time, then go in and help them back to sleep.

Help Your Baby Back to Sleep Multiple Ways

If your baby was eating once or twice a night before the four-month regression, they should not all of a sudden need to eat four+ times! Babies do often go through a growth spurt at this age, so if they’ve only been getting one night feed and now seem to need two, that’s totally reasonable! But they very likely don’t need more than that.

As a general rule of thumb, if it’s been around three hours or more since their last feed and you think they’re hungry, go ahead and feed them! If it’s not yet been three hours, however, and you’re confident they had a full feed earlier, try patting, shushing, or rocking them back to sleep. If you’re a breastfeeding mom, this is a good time to send dad in so your baby is not confused as to why you’re there but not feeding them!

Transition Out of the Swaddle

If your little one is still in a swaddle, it’s time to transition out. Even if your baby is not yet able to roll over, movement is such a big piece of learning to self-soothe, so we want to give them the ability to do so! They may want to sleep with their hands over their head, fist by their mouth, or along the side of the crib, and having the ability to figure out that sweet spot is so important!

Consider Sleep Training

The exciting news is, four-month-olds don’t simply hit a regression, they are also now at an age when they are able to more purposely use their little arms and body, which means they can learn to settle themselves to sleep. So this is the age when we can officially start sleep training, if that’s something you’re hoping to do!

If you’re curious about the best time to sleep train, read this blog post.


The four-month regression is unavoidable, as all babies’ sleep physically changes around that time. However, what the regression actually looks like is different for every baby!

The good news is, the four-month sleep regression does not last forever. The above strategies will not only help you survive the four-month regression, but they will also help you come out of the regression and continue moving toward solid sleep!

If you’re in the thick of the four-month sleep regression right now and just don’t know how to come out of it, or maybe you’re prepping for the four-month regression, we have a resource just for you! Baby Sleep from A to Z is our online sleep class with everything you need to know about your baby’s sleep, from 4-17 months. Check it out!

With Grace,