The 4 Month Sleep Regression
Let’s talk sleep regressions. I hear from parents all the time who attribute their little one’s sleep problems to this regression or that regression. And, yes, there is certainly truth to regressions causing upsets in sleep; but just because they exist doesn’t mean that you have to throw up your hands and resign to sleepless nights. You’re not stuck with a poor sleeper; there are things you can do to help you navigate regressions.
Most regressions are attributable to milestone achievements - both physical and cognitive - and should resolve themselves within a week or two assuming your little one had good sleep skills to begin with. However, there is one regression that is different from the rest and is a total reorganization of the body and the brain. That, my friends, is the four-month sleep regression.
I want to take some time to break down what exactly is going on developmentally around this time and why your previously angelic sleeper is now keeping you up all night.
The Science Behind The Four-Month sleep Regression
Many people think of sleep in black-and-white terms: you’re either asleep, or you’re not. In reality, this cannot be farther from the truth. We all sleep in stages ranging from light to deep and these different stages make up a “sleep cycle” that we transition through several times each night.
When babies are born, their sleep is drastically different from the sleep of adults. Newborns really only have TWO stages of deep sleep whereas adults have FOUR stages ranging from very light to very deep. Because your newborn sleeps so deeply, it is easier to transfer them from your arms to a bassinet without waking them, and to keep them sleeping in all types of situations. When your baby undergoes the biological shifts that occur around four months, they “graduate” to a four-stage cycle that they will follow for the rest of their lives.
But why do some infants have such a hard time whereas others do not?
Now that infants are spending more time in lighter stages of sleep, there is more potential to be woken both from environmental noise and natural occurrences. As adults, we usually “come to the surface of sleep” every 60-90 minutes as we cycle through sleep stages from light, to deep, to light again. In between sleep cycles, we experience a partial-awakening that we don’t remember the next morning as long as certain comforting truths are in place: we are in our beds, it is still dark out, our partner is sleeping next to us, and we have hours to sleep until morning. These periods of transition are so brief and so benign, that we have no conscious memory of them when we wake the next day.
Infants experience similar sleep patterns. They will begin to come to the surface of sleep every 60-90 minutes as well. But let’s say you nursed (or rocked, or held, or cuddled) your little one to sleep and put them down in their crib once you were sure they were deeply in dreamland. When they later awaken between their cycles, even briefly, chances are you are no longer nursing them (or rocking, or holding, or cuddling them). Suddenly, they are in a situation that is vastly different than the one in which they fell asleep. This is no doubt going to be startling and cause a full-blown wake-up instead of a simple transition into another sleep cycle.
Also, around this time, there is a cognitive surge and infants become much more aware of their surroundings. That means that those infants who rely heavily on external strategies to fall asleep (nursing, rocking, bouncing, etc.) are more likely to protest when those things are absent during the night. They strongly believe they need those specific circumstances to be able to "make sleep come".
Up until now, you could have been sailing through, rocking your baby to sleep and everything had been fine. But, if your little one believes they need certain circumstances to fall asleep, these developmental changes can cause major problems.
So now that you understand what is going on, what can you do? Here are a few things that I recommend to help encourage better sleep.
Getting through the Four-Month Sleep Regression
+ Make the room dark
Darkness plays a huge role in cuing our body clocks to get in line with spending the majority of sleep at night time. That doesn’t mean there won’t be wake-ups, or a feed won’t be needed, but this will help to encourage sleep to come. Darkness will also cue the body to develop melatonin which will help your baby sleep for longer stretches
+ Use a noise machine
Because your baby is spending more time in a lighter sleep, white noise can block out any jarring environmental sounds that could pull them into full wakefulness.
+ Implement a bedtime routine
Routines cue the body and brain that we are transitioning out of day and into the night. This is true for adults too (think about your bedtime routine, and even how you fall asleep: which side of bed you have to be on, what’s on your nightstand, what position you lay in, etc.) When structuring your routine, think about offering a feeding towards the beginning or middle of the routine rather than at the end. This minimizes the chances that baby will fall asleep at the breast or bottle which can perpetuate the dreaded cycle of needing you to repeat the bedtime process all. night. long.
+ Choose an early bedtime
Based on research, most infants’ body clocks trend towards a 7pm bedtime and a 7am wake-up, so don’t try to fight nature. And if you can get your little one down this early, think of all the free time you’ll have in the evening to do…whatever you want!
+Be aware of wake windows
Prior to this, your little one might have just fallen asleep whenever, wherever. Consolidated nighttime sleep is aided by honoring daytime sleep. Being cognizant of how long your little one can tolerate being awake will help to prevent over-tiredness which can lead to poor sleep quality. Around 4 months, infants can only tolerate about 1.5 – 2 hours of time awake before they are going to start to get overtired.
+ Put your baby down awake
This helps encourage your little one to fall asleep independently and prevents them from thinking they always need someone or something else to fall asleep. We don’t want you to get stuck in a cycle where you’re going to have to come in throughout the night to recreate the situation that got baby to sleep in the first place!
+ If your baby cries out in the middle of the night, wait for a moment before going to them.
Their cries could just be them transitioning from one light sleep cycle to another and they are not actually fully awake and needing something. This also gives your baby the opportunity to try to get back to sleep on their own
+ Hold them to their personal best!
Last but not least, give your little one credit where credit is due! If they showed you one night that they can sleep a five-hour stretch without needing a feed, then you want to encourage that because you know it’s possible.
Regressions are bound to happen. Oh Baby is here to help you navigate the extra tricky ones. Check out our Infant Sleep Package to get a handle on the four-month-sleep regression once and for all. If your child has previously been a great sleeper, visit our Mini Consultation for support with later regressions.