Navigating the Four Month Sleep Regression

You’ve probably just started to settle into your routine with your new baby. And before you know it, your maternity leave is almost over. Going back to work after spending the last few months or weeks with your new baby can be a really emotional time. The thought of having to wake up and be out the door by 7 a.m. after being up all night with your baby can feel overwhelming.

The transition back to work can be especially challenging if your baby isn’t sleeping at night. Maybe your baby used to be a great sleeper when you were on maternity leave and now seems to be going through a regression. Or maybe your baby never slept well and their sleep seems to be getting even worse lately.

As a professional baby 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. Some people subscribe to the idea that there’s the 4-month sleep regression, a 8-month baby sleep regression, a 9-month baby sleep regression, a 1 year baby sleep regression, as well as teething regressions, growth spurt regressions, and so on. Others see these as simple hiccups caused by extenuating circumstances.

But the 4-month old sleep regression, everybody agrees on, and for good reason. It’s the real deal, and it’s permanent. And I am here to give you all the help you need!

So in order to understand what’s happening to your baby during this stage of the baby 4-month sleep regression, first you need to know a few things about sleep in general. So here’s the science-y part, told in plain English.

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. These stages make up the “baby sleep cycles,” which we all go through several times a night. The first step to getting your baby 4-month sleep regression help is to understand the stages of sleep.

Stages of Sleep

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.

How Your Baby’s Sleep Changes After the 4-Month Sleep Regression

So what does this have to do with the baby 4 month sleep regression help we were talking about?

Well, newborn sleep only have 2 stages; 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 sleep 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. 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. 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.

Signs That Your Baby is Going Through the 4-Month Sleep Regression

The first sign is critical thinking skills. A 4 month old baby, of course, lacks these critical thinking skills. To a 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 having dinner. And someone was singing me a soothing song about the a twinkling 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 baby?

Anyways, now that baby’s suddenly realized that Mommy’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.

Sleep Props

The second sign indicating your baby is going through the 4-month sleep regression  is “sleep props.” A sleep prop is something external that your baby uses to get to sleep. So generally, up until this point, parents have either been putting their baby to sleep by rocking them, bouncing or by breastfeeding them, or some similar technique where baby is helped along on the road to falling asleep. Check out how to break the nightly feeding to sleep habit.

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. 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.

Is There a Solution?

So, the good news for anyone experiencing the dreaded 4-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.

So, onto the big question… what can you do to help baby sleep? Is there a solution? You betcha mama! Here are my top 3 tips:

1) Darkness

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. So you may think that it’s comforting to have a little bit of light coming through the windows or seeping in from the hallway.


The baby’s room should be dark. I mean coal mine on a moonless night kind of dark. This will provide some baby 4-month sleep regression help. 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.) I use the EZ Blackout Window Covers.

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. The brain secretes hormones accordingly, so we want to keep that nursery absolutely pitch black during naps and bedtime.

2) White Noise

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. This will wake them up, so a white noise machine is a great addition to your nursery.

“Wait, is that not 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 and instead something that can provide help.

3) Sleep Schedule for 4-Months

It’s important to ensure your baby is getting enough sleep during the day and at night. A four month old’s sleep schedule is incredibly important. To help with your baby’s naps, here’s how much sleep your baby needs during the day:

Your daytime schedule should include 3-4 naps a day. Each of those naps should be between 1.5 –  2 hours long. If your baby is taking short naps, here’s some tips on how to extend nap lengths

Bedtime routines are also an essential component to providing a solution to your little one’s sleep. 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. 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. Here’s the bedtime secret that every mom must know

If you’re noticing baby getting fussy before bedtime, you’ve probably waited too long. A four month sleep schedule should really only have baby going about two hours between snoozes. Bedtime should be between 6:30 and 8 at night. 

How to Handle Night Feeds During the 4-Month Sleep Regression

How about night feeds? Now that my baby has gone through this big development, does this mean that I can’t feed my baby at night anymore? You can absolutely still do a nighttime feeding or two. Most babies aren’t ready to sleep through the night until they’re around 15 lbs or 6 months of age.

When I work with families to create a customized sleep plan and provide a permanent solution to their baby’s sleeping issues, I generally do keep one or two feeds at night. The key to the baby 4-month sleep regression night feeding is just to make sure that your little one isn’t falling asleep during that feed.

Future Sleep Regressions

Now, there are going to be regressions, actual regressions, later on in your little one’s youth. Check out our sleep regressions ages blog to learn all about the sleep regressions you’ll encounter as your little one gets older. 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.

Sleep Training Your 4-Month Old

And by taking this opportunity to teach them the skills they need to string those baby sleep cycles together, independently, prop-free, without any need for nursing, rocking, or co-sleeping, 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 provide your baby 4-month sleep regression help. Just visit my website or give me a call and we can work on a more personalized program for your little one using gentle sleep training methods. The most common thing I hear after working with clients is, “I can’t believe I waited so long to get some help sleep training baby!” So if you’re considering hiring a consultant, now is absolutely the time. I offer a free 15 minute evaluation so I can get to know the specifics about your little one’s situation, so book a call now and we can move forward as soon as you’re ready to get your little one sleeping through the night!


Kaley Medina is a Certified Sleep Consultant and the owner and founder of Live Love Sleep. She is the proud mama of two little cuties, Evalyn and Leo and was voted the best Dallas Sleep Consultant in Fort Worth, Collins, North Texas and Dallas counties 2 years in a row.