Four Month Sleep Regression… or Progression?

8 August 2018

By Eliana Beeson

Being in the infant sleep business, I’m often exposed to the term “regression” in regards to just about every inexplicable circumstance. Essentially, if baby doesn’t sleep well for a couple of nights, parents tend to associate it with a ‘regression’ issue. Some people believe that there is an 8-month regression, a 9-month regression, a 1-year regression, as well as teething regressions, growth spurt regressions, and so on.

The four-month regression, which everybody agrees exists, is the most renowned and discussed one, and for good reason. The 4-month regression is the real deal, and the process ends when and if baby learns some great self-soothing strategies and independent sleep skills.

So, 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. Let’s look together at the science behind it.

Many of us just think of sleep as an on-or-off situation. You’re either asleep or you’re not. But sleep is actually made up of a number of different stages, all part of what is called a “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. You observe this when you see somebody nodding off in front of the TV. You tell them to go to bed, and you get the canned response of “I wasn’t sleeping!”

Stage 2, is considered the first “true” sleep stage. This is where people tend to realise, once woken up, that they were actually sleeping. For those of you who take “power naps,” this is as deep as you want to go, or else you’re going to wake up dizzy.

Stage 3 is deep and regenerative. Also known as “slow wave” sleep, this is where the body starts repairing and rejuvenating the immune system, muscle 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.

At the end of all 4 stages, we either wake up or get close to waking up, and then we start over again and repeat 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, an important sleep reorganisation happens. At this point, babies transition to the 4-stage sleep cycle explained above, which makes their sleep increasingly similar to that of an adult. That’s why even if we commonly call it a ‘sleep regression,’ which drains our energy and patience levels as parents, I like labelling it a ‘sleep PROgression’. It is indeed an amazing sign of healthy development in your baby, who just needs a little assistance to get through this adjustment successfully and develop healthy sleep habits.

When this transition takes place, a baby typically moves from 50% REM sleep to 25% in order to make room for those first two stages. Although REM sleep is light, it’s not as light as the two new stages 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 an absolutely natural process, and we continue to wake up three, four, five times a night into adulthood and even more in old age.

However, as adults, we are able to identify certain comforting elements that baby might not be attuned to. When we wake in the night, we’re able to recognise that it’s still nighttime, that the alarm isn’t going to go off for another three hours and that there are no good reasons to wake up that moment, so we drift back to sleep… Usually so quickly that, the next morning, we don’t even remember that brief encounter with consciousness.

We would love the same to happen to our lovely four-month-old baby. But of course, she still lacks these critical thinking skills. To a four-month-old baby who fell asleep at her mother’s breast, the reasoning could be more like, “OK, last thing I remember, there was a familiar, beloved face, I was having dinner, and someone was singing me a soothing song about a Teddy Bears’ Picnic (my husband’s favourite BTW!). Now, I’m alone in this dark room, there’s no food, and there are 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?

In any case, now that baby has suddenly realised that Mummy is not around, and they are not entirely sure where she is, the normal response is to have a little freak out. That stimulates the fight-or-flight response and, next thing you know, baby is 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 dummy, or by rocking them, or by feeding them, or by some similar technique where baby is helped along on the road to falling asleep.

Now that baby is spending more time in light sleep, and therefore has a higher probability of waking up, guess what? This suddenly becomes a much bigger issue. These sleep props or sleep associations can become very sneaky at this stage. Although they may be helpful in getting your little one to that initial nodding-off stage, their absence upon waking means that baby is not able to get back to sleep again without some external help. Cue the fight-or-flight, the crying, and the adrenaline. When this starts happening every half-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 a “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”.

But let’s move onto the big question. What can you do to help your little one adjust? First off, get all of that light out of baby’s room. I’m serious about this. 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.


Baby’s room should be dark, as dark as a cave is. Tape garbage bags over the windows if you have to, or cover them with tinfoil.

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 suppresses melatonin production accordingly, so we want to keep the baby’s bedroom absolutely pitch black during naps and bedtime.

The other nemesis of daytime sleep, (and nighttime sleep for that matter, although not nearly as often) is noise. Whether it’s the courier ringing the doorbell, the dog warning you that the neighbour is in your garden again, or something falling on the floor three rooms away. With baby spending more time in lighter sleep, noises will startle them more easily and wake them up. At this point, a white noise machine is a great addition to your “sleep support accessory set.”

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 “sleep association” that we talked about earlier.If notice that your baby is getting cranky 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 childhood. 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 help them develop the skills they need to string those sleep cycles together, independently, prop-free, without any need for nursing, rocking, or dummies, you’ll have given them a gift that they’ll enjoy for the rest of their 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 lucky and enjoy your success. For those of you in the latter camp, I’m here to help. Just visit my website or give me a call and we can work on a more personalised sleep approach 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 consultant, now is absolutely the time. I offer a free 15-minute sleep evaluation call so I can get to know the specifics of your little one’s situation. Book a call now, and we can get your little one sleeping through the night!

Link to book a FREE 15-minute sleep evaluation call:

Posted on August 8, 2018


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