The 4 Month Sleep Regression

As a sleep consultant, I hear the term “regression” used to explain 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 believe that there’s an eight month regression, a nine month regression, a one year regression, 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 can be a doozy. It’s the real deal, and it’s permanent.

In order to understand what’s happening to your baby during this stage, first you need to know a few things about sleep in general.  Allow me to get science-y for a few minutes!

Many of us just think of sleep as an on-or-off switch. You’re either asleep or you’re awake. 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 the 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 and they adopt the 4-stage method of sleep that they’ll continue to follow for the rest of their lives. 

Around this age, 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. 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 as we age.

As adults, however, we’re able to identify certain factors that baby might not recognize. 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”

So we do. And usually so quickly that we don’t even remember this waking in the morning.

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 is more along the lines of, “OK, last thing I remember, I was having dinner in mommy’s arms, and someone was singing twinkle twinkle. Now I’m alone, it’s dark, there’s no food, and there’s gotta be some scary monsters in the immediate vicinity.”

That’s probably an exaggeration, but who knows what’s actually going through their mind?

Anyways, now that baby suddenly realized that mommy is not around and they’re not entirely sure where she went, the natural response is to freak out a bit. This 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 development is that up until this point, parents have either been putting their baby to sleep with a pacifier, by rocking them, by feeding 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 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 props 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 rush. When this starts happening every half an hour, parents can find themselves in a frustrating 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 more appropriately titled the “Four Month Sleep Progression”

So, what can you do to help your child adjust?

First off, get all the 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. 

Nope.

Baby’s room should be dark. Like can’t see your hand in front of your face dark. 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, very 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 dark during naps and bedtime. 

The other nemesis of daytime sleep is noise. Whether its your latest Amazon purchase being delivered, the dog warning you that the squirrels are back and definitely going to attack the house this time, or maybe 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? 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.

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 feed to sleep habit that we talked about earlier. 

So try to put a step or two in between the feed and laying down in the crib to make sure there is no association with feeding and sleep. 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 7 and 8 at night.

Now, there are going to be regressions, actual regressions, later on in your little one’s youth. Traveling, illness, teething: 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. Just send me a message or book your free 15 minute discovery call and we can discuss a personalized sleep plan for your little one. 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 sleep consultant, now is absolutely the time.