The 4 Month Sleep Regression

The Four Month Sleep Regression

Just like many of you, I LOVE my sleep. I know that when I’m getting a full night’s sleep, I feel much more prepared to tackle the day, between keeping my tiny humans alive, having the motivation to eat well and workout, get my work done, and then also manage to get some self-care time in for myself. And if I don’t get enough sleep, I feel like I half-ass everything and walk around with my head in a fog.

In case you didn’t know this, we welcomed our second baby back in January, and so he is just about 4 months old. In the early weeks, as any newborn, he woke up frequently, because he had to eat every 2-3 hours. And that’s normal. But, with my sleep consultant training, I also knew how to help him start sleeping longer stretches as early as possible.

For us, that looked like one middle of the night feed between an 8:30pm bedtime and 7am-ish morning starting around 7-8 weeks, and he was sleeping 12 hour stretches overnight at 13 weeks. We are also on a 3-nap schedule most days, with two of those naps being 1.5-2 hours long.

Keep in mind that NOT all babies are ready to drop that last nighttime feed until they are over 15 pounds or 6 months old, but many babies are able to do so! Here’s what I would say is an “ideal” schedule for a 16-week old baby:

But, as I’m sure you’ve heard about, around 4 months old, many babies experience what is famously known as the “Four Month Sleep Regression”. I wanted to refresh my memory about making it as minimal of an issue as possible, and I know many of you would love to read more about it as well.

If you are experiencing the 4-month sleep regression, and want some professional advice- don’t wait! Reach out now, and schedule a free, 15-minute call with me so we can discuss actual solutions that will solve your sleep issues.

For us, it definitely hit right under the thundercloud on the Wonder Weeks app. We had short naps that day, lots of crankiness, and an early morning wake-up the next day. Thankfully, it only lasted that one night.

The Four Month Sleep Regression-

And how to avoid it all together!

As a professional sleep consultant, I hear the term “regression” used in regards to just about every imaginable circumstance. Essentially, if baby doesn’t sleep well for a couple of nights, parents start dropping the ‘R’ word.

Thanks to social media, and some certain apps that I’m sure some of you are familiar with, some people now subscribe to the idea that there’s an eight month regression, a 9 month regression, a 1 year regression, 18 month regression, 22 month regression , etc. as well as teething regressions, growth spurt regressions, and so on. Others see these as simple hiccups caused by extenuating circumstances.

But the four-month regression, everybody agrees on, and for good reason. It’s the real deal, and it’s permanent.

Before we jump right into how to fix it, I think it’s worth spending just a moment on the science of baby brains and how their development affects their sleep. (Don’t worry, I won’t bore you with science speak.)

Many of us just think of sleep as an on-or-off situation. You’re either asleep or you’re not. But sleep actually has a number of different stages, and they make up the “sleep cycle,” which we go through several times a night.

  • Stage 1 is that initial stage we’re all familiar with where you can just feel yourself drifting off, but don’t really feel like you’ve fallen asleep. Anyone who has ever seen their partner nodding off in front of the TV, told them to go to bed, and gotten the canned response of, “I wasn’t sleeping!” knows exactly what this looks like.
  • Stage 2, which is considered the first “true sleep” stage. This is where people tend to realize, once woken up, that they actually were sleeping. For anyone taking a “power nap,” this is as deep as you want to go, or else you’re going to wake up groggy.
  • Stage 3 is deep and regenerative. Also known as “slow wave” sleep, this is where the body starts repairing and rejuvenating the immune system, muscles tissue, energy stores, and sparks growth and development.
  • Stage 4 is REM (rapid eye movement) sleep. This is where the brain starts to kick in and consolidates information and memories from the day before. It’s also the stage where we do most of our dreaming.

Once we’ve gone through all of the stages, we either wake up or come close to waking up, and then start over again until the alarm goes off.

So what does this have to do with the dreaded regression we were talking about originally?

Well, newborn babies only have 2 stages of sleep; stage 3 and REM, and they spend about half their sleep in each stage. But at around the third or fourth month, there is a reorganization of sleep, as they embrace the 4-stage method of sleep that they’ll continue to follow for the rest of their lives.

When this change takes place, baby moves from 50% REM sleep to 25% in order to make room for those first two stages. So although REM sleep is light, it’s not as light as these 2 new stages that they’re getting used to, and with more time spent in lighter sleep, there’s more of a chance that baby’s going to wake up.

That’s not to say that we want to prevent or avoid baby waking up. Waking up is absolutely natural, and we continue to wake up three, four, five times a night into adulthood and even more in old age.

As adults, however, we’re able to identify certain comforting truths that baby might not be privy to. When we wake in the night, we’re able to recognize that, “Hey, I’m here in my bed, it’s still nighttime, my alarm isn’t going to go off for another three hours, and I’m reasonably certain that there are no monsters lurking under my bed. I can go back to sleep”.

And we do. Usually so quickly that, the next morning, we don’t even remember the brief encounter with consciousness.

A four month old baby, of course, lacks these critical thinking skills. To a four month old baby who fell asleep at her mother’s breast, the reasoning could go much more to the tune of, “OK, last thing I remember, there was a familiar, beloved face, I was drinking warm milk, and someone was singing me Twinkle Twinkle Little Star. Now I’m alone in this dark room, there’s no food, and there’s probably at least three, possibly four, scary monsters in the immediate vicinity.”

That’s probably an exaggeration, but who knows what goes on in the mind of a four month-old baby?

Anyways, now that baby’s suddenly realized that Mama’s not around, and they’re not entirely sure where they’ve gone, the natural response is to do a little freaking out. That stimulates the fight-or-flight response and, next thing you know, baby’s not going back to sleep without a significant amount of reassurance that everything is OK.

The other major contributor to this 4 month fiasco, I find, is that up until this point, parents have either been putting their baby to sleep with a pacifier, or by rocking them, or by breastfeeding them, or some similar technique where baby is helped along on the road to falling asleep.

Now that baby’s spending more time in light sleep, and therefore has a higher probability of waking up, this suddenly becomes a much bigger issue. These sleep props or sleep associations can be very sneaky indeed, because although they may be helpful in getting your little one to that initial nodding off stage, the lack of them when they wake up means that baby’s not able to get back to sleep again without some outside help. Cue the fight-or-flight, the crying, and the adrenaline. When this starts happening every half an hour, parents can find themselves in a nightmarish situation.

So, the good news for anyone experiencing the dreaded Four Month Sleep Regression is that it’s not, in fact, a regression at all. A regression is defined as “reversion to an earlier mental or behavioral level,” and that’s actually the opposite of what your baby is experiencing. This would be much more aptly titled the “Four Month Sleep Progression”.

Moving onto the big question. What can you do to help your little one adjust?

How to Avoid the 4 Month Sleep Regression All Together

First off, get all of that light out of baby’s room. I’m not kidding around here. You might think that baby’s room is dark enough, or that baby might not like the dark, and that it’s comforting to have a little bit of light coming through the windows or seeping in from the hallway.


1. Baby’s room should be dark. I mean coal mine on a moonless night kind of dark. On a scale of 1 to 10, it should be a TEN. Tape garbage bags over the windows if you have to, or cover them with tinfoil. (Just be prepared to explain it to the police when the neighbors accuse you of running a grow- op.)

Newborns and infants are not afraid of the dark. They are, however, responsive to light. Light tells their brains that it’s time for activity and alertness, and the brain secretes hormones accordingly, so we want to keep that nursery absolutely pitch black during naps and bedtime.

2. The other nemesis of daytime sleep, (and nighttime for that matter, although not nearly as often) is noise. Whether its UPS ringing the doorbell, the dog warning you that the squirrels are back and for sure going to attack the house this time, or something falling on the floor three rooms away. With baby spending more time in lighter sleep, noises will startle them easily and wake them up, so a white noise machine is a great addition to your nursery.

“Wait, isn’t that a prop,” you’re asking. Well, in a way, it is, but it doesn’t require any winding, resetting, reinserting, or parental presence. It’s just there and it can be on as long as baby’s sleeping, so it’s not a prop we need to avoid. Plus, you’ll find that if you forget to turn it on one night once baby is sleeping well, baby will most likely continue to sleep well.

3. Bedtime routines are also an essential component to getting your baby sleeping well. Try to keep the routine to about 4 or 5 steps, and don’t end it with a feed. Otherwise, you risk baby nodding off at the breast or the bottle, and that will create the dreaded “association” that we talked about earlier.

So try to keep the feed near the beginning of the routine and plan the songs, stories, and getting into PJs towards the end. The whole process should be about 20 – 30 minutes long, and baby should go into their crib while they’re still awake.

If you’re noticing baby getting fussy before bedtime, you’ve probably waited too long. Four month old babies should really only be going about two hours between snoozes, and bedtime should be between 6:30 and 7:30 at night.

Now, there are going to be regressions, actual regressions, later on in your little one’s lifetime. Traveling, illness, cutting teeth, all of these things can cause your little one to have a few bad nights in a row. But when it comes to the four month “progression,” I’m happy to report that this is a one-time thing.

Once you’re through this, your baby will have officially moved into the sleep cycle that they’ll essentially be following for the rest of their life. Four glorious stages repeated multiple times a night.

And by taking this opportunity to teach them the skills they need to string those sleep cycles together, independently, prop-free, without any need for nursing, rocking, or pacifiers, you’ll have given them a gift that they’ll enjoy for the rest of their young lives.

Of course, some kids are going to take to this process like a fish to water, and some are going to be a little more resistant. If yours falls into the former category, count yourself as lucky, take delight in your success, and go ahead and gloat about it on Facebook.

For those of you in the latter camp, I’m happy to help in any way I can. The most common thing I hear after working with clients is, “I can’t believe I waited so long to get some help!” So if you’re considering hiring a consultant, now is absolutely the time. I offer a free 15-minute discovery call so I can get to know the specifics about your little one’s situation, so book a call now. That way, we can move forward as soon as you’re ready to get your little one sleeping through the night!

Sometimes, you need specific questions answered, but you don’t need a full sleep plan. I recently added an “ASK ME ANYTHING” call, so you get a longer phone call to answer these questions.

Schedule a 30-minute phone call with me by clicking the link below.

Or, if you prefer a DIY version, that will still answer every question you have about baby’s sleep, and result in your baby sleeping through the night, then this is for you.

Bee Wise Sleep School is a self-paced, online course, with step-by-step help for adjusting naps, nighttime, and bedtime routines.

Sleep Philosophy
My sleep philosophy is that all children (and mommas!) need restful sleep, and so my goal is to help children learn independent sleep skills so that they can fall asleep on their own and stay asleep through the night. I will help develop a customized sleep plan that aligns with the family’s wishes.