We’ve discussed sleep regressions a lot, both on the podcast and the blog, but I wanted to dig even deeper into sleep regressions in this post - specifically the 4 month sleep regression. Because this one affects nearly every baby - and often comes as a surprise to many parents since it is the first one to hit. I've also found that many babies are sleeping fine during their newborn phase and so it can really wreak havoc on new parents - it’s the one I see coming up as a trouble spot over and over again!
The 4 month regression can be quite disruptive, and just like the others at 9/10 months, 12 months, 18 months and 2 years, it can lead to more frequent night waking, short - and sporadic - naps and trouble falling asleep during both day and night. However, it is actually quite different than the other regressions your baby may experience - and that’s because it’s actually not really a regression at all. Before I talk about that, let’s take a minute to explore what 4 month old sleep looks like.
4 month old sleep
Around 4 months, your baby will graduate from newborn to true babyhood. This means that you’ll likely notice your baby waking more and being more alert and interactive with the world around them. Your baby will start to be able to stay awake for longer periods (though still we want to aim for no more than 2 hours at a time, for now) - and their sleep will begin to organize a bit more as well. Up until this point, I usually recommend trying to keep to a daily routine with evenly spaced naps (roughly 1-2 hours apart), but it’s typically around this age (somewhere between 4-5 months) when babies are ready for more of a schedule - with 4 (sometimes 5) naps and usually an earlier bedtime than before.
The 4 month regression
The 4 month “regression” is a time when your baby’s sleep patterns are going to change - permanently. So, where they may have slept soundly all night before (if you’ve been one of the lucky ones), they now will begin cycling in and out of sleep just like adults do. And because they are cycling through each of the various stages of sleep, they are also spending more time in the non-REM sleep - or the lighter sleep cycles. This means that they are much more likely to wake. And more importantly, if they don’t know how to get back to sleep on their own, then each time they cycle through they are going to wake up and want you to come calm them back down and help them get back to sleep.
I think the best metaphor for this would be to imagine if you were watching tv and lulled to sleep at night while you were on the couch, but then sometime in the middle of the night you woke up in your bed, you would likely open your eyes, sit upright and be very confused about how you got there. You might ask your partner if they moved you or wonder what happened for so long that you have trouble settling back into sleep. This is exactly what happens when a baby falls to sleep in your arms (or while sucking on a bottle or nipple) and then wakes up alone in their crib.
So, if your baby is jarred awake because they’re in a different atmosphere or situation than they were when they fell to sleep then you’re likely going to be experiencing very frequent wakings. In fact, some babies wake as frequently as at the end of every sleep cycle (so every 45 minutes or so) though most families will note waking every 2-3 hours. And for most babies, the 4 month regression can last 2 to 6 weeks - which makes for very exhausted parents and babies!
Adding to the changes in sleep patterns and cycles, this is also a time when many babies will begin to roll and have to transition out of the swaddle. Additionally, as I mentioned before, there are often a lot of schedule changes around this age as babies naps begin to consolidate and lengthen a bit - allowing them to drop down from 5 to 4 naps (though the regression is notorious for 30 minute naps all day long for awhile!)
So, what can you do?
Let’s take a closer look at this. First, it’s important to note that we all cycle through sleep throughout the night. For adults, older children and even babies who have learned to sleep on their own, we will wake up briefly and roll back over to sleep. But, as I mentioned before, if you were to fall to sleep on the couch and then wake up at 1am and be in your bed, you are very likely to jolt awake a bit out of confusion, right?
Or if you fell asleep on your pillow and now it’s missing and you’re on the floor? So, the same principle applies to your baby - and it’s why we see so many wakings around this time. If your baby fell asleep in your arms - or while sucking on a bottle or your breast - and then wakes up all alone in their crib then they are much more likely to jolt awake and to cry out than if they were to simply wake up in their crib just like they had been when they fell asleep. Make sense?
So the key is to help your baby learn to fall asleep on their own - and to drop the sleep props that they may be counting on. Once we’ve addressed the sleep props, we want to also look holistically at your baby’s needs. Overtiredness is a huge contributor to short naps and trouble falling and staying asleep, so ensuring that your baby is on an age appropriate schedule and going to bed at the “right” time can be immensely helpful. At 4 months, we’d expect that babies are taking 4-5 naps (for a total of roughly 3-4 hours) and can stay awake for no more than 2 hours before they become overtired. And to really head it off, try to aim for your baby to be asleep by that 2 hour mark, not just starting the bedtime routine.
Finally, make sure that your baby’s sleep environment is conducive to their best sleep. As babies begin to wake up to the world, it becomes even more important that you help them tune out disruptions like house noises and sunlight streaming through the windows. So, if you haven’t already, ensure that your baby has white noise and black out blinds in their room - both for nights and naps.
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