The Four Month Sleep Regression

As a Certified Sleep Sense consultant, I hear the term “regression” used in just about every challenging circumstance relating to Bubs.  If bub does not sleep well for a couple of nights, parents start commenting that baby is having a regression?   Talk is that there is a 4th, 8th, 9th and 12th month regression, as well as teething regressions, growth spurt regressions, and so on and so on. 

But the four-month regression, seems to be the one that everyone agrees on, for good reason.

So to be able to understand what is happening to your bub during any of these regression stages you firstly need to know a little about the biology behind sleep.

Many of us think of sleep as either you are asleep or you are not. But sleep actually has 4 different stages, and they make up our “sleep cycles,” which we go in and out of all night.

Stage 1 (light) is that first stage where you can just feel yourself drifting off, but don’t really feel like you have fallen asleep.  

Stage 2 (still light) which is considered the first “true sleep” stage. This is where people tend to realize, once they have woken up, that they actually were sleeping. 

Stage 3 (deep) is regenerative and deep.   This is 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 processes the day and neural pathways are created and the brain consolidates information and memories from the day.  This is the sleep that if someone tried to wake you, it would take them a while to rouse you and then when you woke you would feel a little disorientated and take a bit to realise where you were etc. This is the stage where we do most of our dreaming.

Once we have gone through all 4 of the sleep stages, 1 sleep cycle, then we either wake up or come close to waking up, and then we start our sleep cycle all over again until the alarm goes off.

So what does this have to do with the dreaded regression?

Newborn babies only sleep in 2 stages of sleep, stage 3 and REM, the deeper stages, they spend about half their sleep in each stage. But around the third or fourth month, there is a reorganization of sleep, as their sleep patterns start to look more adult like and they start sleeping in the 4-stage method of sleep.  They will continue to follow this 4 stage pattern for the rest of their lives.

When this change starts taking place, bubs 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 getting used to, and with more time spent in lighter sleep, there is more of a chance that bub’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.  Bub’s just needs to be able to wake in a sleep cycle know where they are, be happy and comfortable, close their eyes and go back to sleep and not be reliant on the parent to come in and help them go back to sleep.  

Also, if bub is heavily reliant on any prop, then when they enter that lighter stage of sleep and the sleeping conditions are not exactly the same as when they went to sleep (i.e. dummy was in and now it has fallen out), then Bub is going to cry out for someone to come and put that dummy back in or do whatever was done for them when they originally had fallen asleep.

So as adults, when we wake from a sleep cycle, we are able to recognise that we are feeling cold, or we have lost our pillow, we can pull up our doona find our pillow and go back to sleep .   And we do. Usually so quickly that, the next morning, we don’t even remember the brief waking.

A four month old baby, lacks these serious thinking skills. To a four month old baby who fell asleep with a dummy, being rocked or at their mother’s breast, wakes from a sleep cycle and the environment is not the same, their thoughts would be “OK, last thing I remember, there was a beloved face, I was having a feed, and someone was singing me a soothing song about twinkly stars. Now I am alone in this dark room, there is no food, and no soothing song.”   

Now that baby has suddenly realized that Mummy is not around, and they are not entirely sure where they have gone, the natural response is to CRY. That stimulates the fight-or-flight response and, next thing you know, baby is not going back to sleep without a substantial amount of reassurance that everything is OK.

The other major contributor to this 4 month debacle, is that up until this point, parents have either been putting their baby to sleep with a dummy, rocking them, feeding them, or some type of technique where baby is helped along on the path to falling asleep.  

Now that baby is spending more time in light sleep, there is higher probability of waking up, this suddenly becomes a much greater issue. These sleep props can be very devious indeed,  they may be helpful in initially getting bub’s to head off into that first stage of sleep, but the problem then occurs that lack of them when they wake up means that baby is not able to get back to sleep again without that sleep prop.  When this starts happening every half an hour, all night then parents can find themselves in a hellish situation.

So, what can you do to help your Bub get their sleep back on track?

So firstly, there must be NO light in Bub’s room. You may think that your baby’s room is dark enough, or that baby might not like the dark, and that it is reassuring to have a little bit of light coming through the windows or seeping in from the hallway.  The answer to that is NO! 

Baby’s room should be dark. I mean dark as a cave.  Cover the windows with alfoil.

Newborns and infants are not afraid of the dark. However, they are responsive to light.  Light communicates to their brains that it is time for activity and alertness, and the brain then secretes the hormone, cortisol.  

The other enemy of daytime sleep, (and night-time for that matter) is noise. Whether it is someone ringing the doorbell, the dog barking, or something falling on the floor five rooms away. With the baby spending more time in lighter sleep, noises will startle them easily and wake them up, so a white noise machine or fan is a great addition to your nursery.

Bedtime routines are also an essential element to get your baby sleeping well. Try to keep the routine simple, and never end it with a feed. Otherwise, you risk baby falling asleep on the breast/bottle and that will then create an “association” that I talked about earlier.

The whole process should be about 20 - 30 minutes long, and baby should go into their cot while they are still awake.

If you notice baby getting grumpy and upset before bedtime, you have probably waited too long. Four month old babies should really only be awake for approximately 2hrs, and bedtime could be anywhere between 6pm and 8pm.

So there are definitely going to be actual regressions, later on in your baby’s life. Illness, travelling new family member all of these things can cause your bub to have a few bad nights in a row.  If you are able to teach them the skills they need to string sleep cycles together, independently, prop-free, without any need to feed, use dummies or rock to sleep, then you will have given them the gift of sleep for the rest of their young lives.  Four magnificent stages of sleep repeated multiple times every night, without you having to enter their room.