The 4 Month Sleep Regression Explained

4-16 months

Sep 20, 2020

If you’re reading this, you are one of two types of people:

  1. You either have a newborn and you are truly terrified of the 4-month sleep regression
  2. You have a 4 to 5-month-old and you are wondering what happened to your great sleeper?! 

In today’s blog, I’m going to share with you what in the world is happening during the 4-month sleep regression period and 3 ways that you can come on the other side a lot more well-rested. 


The Four Month Regression is not a myth or a scare tactic. Perhaps you’re currently getting emails from BabyCenter or What to Expect warning you about the 4-month mark. Or maybe you’ve just heard about it from friends. The four-month regression IS real, but I want you to reframe it in your mind.

Simply, what’s happening is your baby is maturing, and they’re growing up, which is good! 

Newborn sleep cycles vs baby sleep cycles are completely different things.

Newborns have two sleep cycles that they rotate in and out of: deep, non-deep, REM, non-REM. That’s all.

Once we get to 4 months old, around 16 weeks from due date, your child now develops fully mature sleep cycles just like you and I.

So they go from having just two sleep cycles to more complex sleep cycles that go in and out of stages while they sleep.

They are no longer newborns! We want to celebrate the fact that your child’s sleep needs are growing and changing!

As a mom, I have a sweet spot in this 4 month period. It brings back a flood of memories because my whole journey with sleep consulting started with my oldest at this time. So if you’re reading this and you’re in that awkward 3 to 4 month period where things are drastically changing, I want to give you 3 things that I was unaware of at this 4-month mark.

You can do all 3 of these today and my goal is that you can come to the other side of the 4 month period a lot more well-rested!


How To Move Past The 4 Month Sleep Regression


This may scare you a little bit, but here’s why this needs to happen. A swaddle is a fantastic tool for newborns; they cannot control their body, they cannot self-soothe and they struggle with the startle reflex.

Now, you may be thinking, “My 4-month-old still struggles with the startle reflex, so I’m not getting them out of the swaddle.”

But how is your 4-month-old ever going to learn to use his or her body if we just keep them wrapped up like a burrito?

Again, swaddles are great for newborns, but in my Newborn Sleep Course, I actually ask parents to start thinking about getting arms out of the swaddle, one at a time, between 8 and 12 weeks old. 

If your baby is still in a swaddle at four months I want you to move to the cold turkey method of getting out of the swaddle and moving right into a sleep sack.

I love the traditional open-arm sleep sacks because you can use these for a long time.

But the Zipadee-Zip sleep sack is a great option that is actually designed for this 4 month period. The Zipadee-Zip was originally designed to help your child come out of the swaddle and have more freedom, but still, when they startle, they won’t fully wake up. 

It’s important to start getting out of the swaddle so they can learn how to use their body.

When you and I sleep at night, we’re not stationary. We’re switching positions, we’re putting our arms under our pillow, we’re laying on our back, we’re laying on our side – however you sleep, you’re in full control. It might feel weird that your baby is ready to be in full control, but they are!

Four-month-old babies are starting to learn how to use their body, they’re starting to learn how to manipulate themselves in the crib, and roll from back to belly, belly to back, or go on their sides. This is normal and good, and we have to get out of the swaddle so that those movements are safe. 



Step two is to help your baby nap more in their crib. Most of the time, around this 4-month mark, your child loses the ability to easily be transitioned from car seat to crib.

Have you noticed that?

Babies this age are more aware. They’re not the sleepy newborn anymore! The awake times are increasing and their sleep cycles are changing. This is why I really want you to try getting them into their crib.

This goes along with a YouTube video that we already have on going from a bassinet to a crib, so make sure you check that one out.

This is the time to make the transition from a bassinet to a crib.  It’s time to focus on more naps in the crib because naps on-the-go are not as restorative as naps in the crib.

Think about it, when you’re on an airplane or in a car and you doze off, do you wake up feeling well-rested? No! And neither does your child. So if we can focus on half of your baby’s naps in the crib, the other half could be on-the-go. 

Now, I know that contradicts what I just said, but here’s the thing: 4-month-olds only have a short awake time. Newborns have 60-minute awake windows. That’s all. Guess what a 4-month-old can handle? An hour and a half to an hour and 45 minutes. It’s not a lot more! So it’s really important that we start to focus on more naps in the crib so your baby can start connecting sleep cycles, but you have a life and you should not be trapped inside your house all the time. 



Yikes, this is probably the scariest of all!!

We want to help your baby sleep better and they will sleep better if they know how to fall asleep all on their own.

It’s time to eliminate things like swaddles, the pacifier, rocking to sleep, feeding or nursing to sleep – whatever it is that is helping your baby fall asleep.

This is a big change and it’s the hallmark difference between newborn and baby.

Newborns need help to get drowsy and fall asleep. Babies need to do this on their own and have all these other props eliminated because it is the only way they’re going to sleep fuller and longer and connect their sleep cycles. 

I want you to think about this: if your baby falls asleep with a prop, whatever it is: nursing, rocking, bouncing, pacifier, feeding, swaddle, whatever it is, they’re going to come out of their sleep cycle looking for that to help them slip back into the next sleep cycle. This will happen all throughout the night and during their naps. Your baby is ready to do this independently. And I want you to know that this is a true gift to give them independent sleep. 



First step: We’re going to ditch the swaddle. You can start that right away and transition your baby to an open arms sleep sack or Zipadee-Zip. It’s important to get them out of the swaddle so they can start exploring their body. 

Second step: We’re going to offer half of your baby’s naps in the crib. At 4 months old, we are aiming for 4 naps per day. Let’s offer 2 (or more) naps inside the crib and the other half can be on the go. We want to give them the opportunity to start connecting their sleep cycles and have better quality sleep during nap time.

Third step: Ditch the props. Evaluate what props just are not working anymore. Are you doing the nursing or rocking or bouncing to sleep and it’s just not cutting it anymore? It’s because they are ready to learn independent sleep habits. Look at all of the sleep props in place that are not working anymore and take them away. They’re just gone. 

Now, a question I get all of the time is:

Do I wait for the 4-month sleep regression to end before I begin sleep training, or can I start sleep training now?

Well, the 4-month sleep regression is not a storm that you wait to pass before you get to go outside and enjoy life again.

That’s not what this is. The 4-month regression is a period of time where your baby is developing mature sleep cycles, and as all these three steps have outlined, they are ready for independent sleep and not depending on anyone or anything else besides themselves.

So, now is the time that you sleep train!

And if your little one has already passed the 4-month sleep regression, or maybe you feel like it has lingered for months, it’s never too late to sleep train! In fact, our Baby Sleep E-Coaching™ program includes two different plans. One is for a 4 to 5-month-old and the other is for a 6 to 16 month-old.

Our 4 to 5 month plan includes more gentle methods for this age and focuses on one nighttime feed.

You don’t have to wait for this storm to blow over. You can begin as soon as you are ready. You have a plan waiting for you, so go for it!


A Pinterest graphic featuring a baby with dark skin and curly hair smiling at someone off-camera. There is a text overlay that says "How To Conquer The 4 Month Sleep Regression"

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