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4 month old sleep: is my baby broken ??

There is so much misinformation when it comes to sleep at 4 months of age, often called the 4 month regression.

Some of this information can create so much fear for parents either who are about to hit this stage or who are going through it.

Here are FOUR key points to help you understand more about what's actually going on and some ideas for how you can support your baby's sleep.

1. Sleep cycle maturing: the sleep cycle is changing and this can fragment sleep. This can happen at any time between about 2-6 months (MacLean et al., 2015)* as they go from having two stages per sleep cycle (REM/NREM) to having the same structure we had as adults (NREM Stages 1-3/REM). It's a completely different way for their brains to move through sleep and it can fragment sleep. For some babies it causes sleep to go completely haywire with wakings every cycle (40-50 mins), for others they might just wake a bit more and for others they are completely unaffected. Unfortunately, we can’t accelerate or 'fix' this developmental milestone but evidence-based knowledge can reduce stress and panic and help you be able to navigate through this stage with more calm and clarity.

2. Your child has not forgotten how, or lost their ability, to sleep: While the change to their sleep cycle is permanent, it's a complete myth that this won't ever improve until you teach your child to self settle. Tell that to all the babies around the world who moved past this stage and slept wonderfully without ever self-settling. An evidence-based view of sleep means we know they aren’t waking at the end of each cycle or more frequently in the night because they no longer know how to sleep and they need 'good sleep skills'. While there is evidence to support that how a child falls asleep can impact their nights there is also evidence that this two things can also be completely unrelated (Hysing et al, 2014**). Importantly, while each child can be completely different with their sleep, we also don't want to completely ignore biological and developmental norms with how babies sleep. Plus, how a baby falls asleep is just one aspect of a much bigger view of sleep so if we focus just on this one thing, we are missing so much of the more important information.

3. Change in sleep needs: While there is no evidence to support awake guides/times, nap schedules, prescribed lengths or patterns of naps, there is great evidence about total sleep recommendations. (Galland et al, 2012; Hirshkowitz et al, 2015***) This evidence supports that at around 4 months they don’t need as much sleep as they previously did and for many babies this means that an adjustment to how much day sleep they are getting may need to be shifted to support better night sleep. There is only so much sleep we all need in a 24 hour period.

4. Cascade of development: there is so much development happening at this stage, so much at once and one thing after another. Development can fragment night sleep as the brain goes to work with pruning, tuning, recalibrating, consolidation of memories and new things (Huber & Born, 2014****). This relates to the myth of the 4 month regression and regressions in general which is the idea there are set ages that sleep goes haywire however there is in fact no evidence to support sleep regressions and leaps, rather it can be much more helpful to recognise that sleep can go up and down whenever there is development happening. The developmental milestones for each child can be rather varied so sleep can get impacted at different times and also some children's sleep is barely impacted, or not at all, by developmental milestones. So while it can help to understand that when your child goes through social, psychological, emotional, physical or verbal development that their sleep may take a hit, trying to box these as set times for all children and with the same impacts can limit our view of the unique journey of each child and their sleep. Approaching a 'regression' can also create fear and dread! For some it can help feeling like they know what's going on which is great however a broader knowledge of what's actually going on with sleep can be far more helpful. Also, with so much development happening around this 4 month mark, all these new things to explore mean they may be more distracted on day feeds so feed more in the night.

So what can you do to support your 4 month old baby's sleep? While we acknowledge the developmental aspects of what's going on, we can also focus on a few things.

  • Create some lovely predictable, nurturing steps for bub’s nap and bedtime routines that can help with regulation and readiness for sleep

  • Experiment with more time awake in the day and/or less total day sleep

  • Protect or rescue sleep when needed whether that's in carrier or car or on you....whatever you find helps especially if things are getting tricky later in the day

  • Lots of opportunities to explore their world and enjoy the new ways they are moving, verbalising connecting and so on

  • Shut out the noise that you must or can 'fix' this stage or that unless you 'fix' sleep now that you're doomed

  • Reduce the expectations for yourself during the days if you can

  • Get outside each day if you can

  • Avoid comparisons remembering that every baby will move through this stage differently

Always love, Annie x

* MacLean, J. E., Fitzgerald, D. A., & Waters, K. A. (2015). Developmental changes in sleep and breathing across infancy and childhood. Paediatric Respiratory Reviews, 16(4), 276–284. doi:10.1016/j.prrv.2015.08.002

**Hysing, M., Harvey, A.G., Torgerson, L., Ystrom, E., Reichborn-Kjennerud, T., & Sivertsen, B. (2014). Trajectories and predictors of nocturnal awakenings and sleep duration in infants. Journal of Developmental & Behavioural Pediatrics. 35(5). 309-316


Galland, B., Taylor, B., Elder D., & Herbison, P. (2012). Normal sleep patterns in infants and children: A systematic review of observational studies. Sleep Medicine Reviews, 16(3), 213-222

Hirshkowitz, M., Whiton, K., Albert, S. M., Alessi, C., Bruni, O., DonCarlos, L., Hazen, N., Herman, J., Adams Hillard, P. J., Katz, E. S., Kheirandish-Gozal, L., Neubauer, D. N., O'Donnell, A. E., Ohayon, M., Peever, J., Rawding, R., Sachdeva, R. C., Setters, B., Vitiello, M. V., & Ware, J. C. (2015). National Sleep Foundation's updated sleep duration recommendations: final report. Sleep health, 1(4), 233–243.

**** Huber, R., Born, J. (2014). Sleep, synaptic connectivity, and hippocampal memory during early development. Trends in Cognitive Sciences. 18(3). 141-152.

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