How Developmental Milestones Affect Sleep

As a mother myself, and a sleep consultant, I've come to the inescapable conclusion that babies, as a rule, are complicated creatures.  Matthew McConaughey’s quote on newborns always gives me a chuckle, "They eat, they crap, they sleep, and if they're crying, they need to do one of the three, and they're having trouble doing it. Real simple." In a way, he's right.  A baby's vital needs essentially break down into sleeping, eating, and pooping.  Their only real form of communicating any issue is through crying. Identifying the fact that there is a problem with our babies is far easier than solving the problem,  and as parents, isn't that all we want?

If you're the parent of a baby who's just figured out how to roll over,  is learning to crawl, or who's teething, this may come as the least surprising scientific discovery imaginable. ​Developmental Milestones often cause disruptions in a baby's sleep.  In a 2015 study published in Monographs of the Society for Research in Child Development, researchers looked at the sleep patterns of babies before they started crawling, while they were learning to crawl, and a few months after learning to crawl. The results stated that "Along with the overall improvement in sleep consolidation, periods of increased long wake episodes were also manifested; the rise in sleep disruption was temporally linked to crawling onset."   To sum it up, the results showed that babies appear to have more night time wake ups around the time that they learn to crawl.  (Nighttime wake ups were monitored by a motion sensor on the baby's ankle and were only counted if the baby was moving around for more than five minutes.)
 
To quote that same study, "In dynamic systems, downward trends in performance and in behavioural control often mark the emergence of new abilities. This pattern has been identified in diverse domains of infant development, including manual reaching, vocal production, and language acquisition."  In other words, things tend to get worse before they get better, and when your little one starts talking, you can expect some random chat sessions in the middle of the night. 
 
Teething is another one of the usual suspects when it comes to disruptions in a baby's sleep. If baby has sore gums, that discomfort is probably going to make it a little tougher to get to sleep and stay asleep.  A study from the April 2000 issue of Pediatrics looked at symptoms that could and could not be attributed to emerging teeth. It found that during the four days before a tooth emerged, the day it popped out, and for the three days following, there was a statistical increase in wakefulness and irritability. Any parent who has dealt with a teething baby has seen how the discomfort that comes along with it can be disruptive to your little one's sleep, understandably so. Though teething is one cause of disrupted sleep, language and movement skills may be responsible for more frequent nighttime wake-ups.
 
Much like the rest of us, babies get excited when they start to learn a new skill.  While watching my little one learn to crawl, it reminded me of when I first discovered how to use  Shazam to identify a song playing over the speakers in Starbucks. I was ridiculously excited!  I couldn't wait for another song to come on so I could try it again.  I started singing obscure '80s pop songs to see if it could nail them down and showed it off to everyone who would listen. To your baby, learning to talk, learning to roll over, or learning to crawl, elicits pretty much the same response. They get a real thrill out of this newfound skill, and they are going to practice it over and over.  In the morning, in the afternoon, and when they wake up in the middle of the night, and that excitement is going to make it a little more difficult for them to get back to sleep.
 
I see a lot of parents looking for a "solution" in this scenario, and in trying to get their baby's sleep back on track, they tend to lose consistency. They'll move bedtimes around, start rocking or feeding baby back to sleep, change up the bedtime routine, anything they think might help.

But the best advice I can give you is to hold steady. You're probably going to have to go in and soothe your baby a little more often during this period. You'll have to help get them out of the uncomfortable positions they manage to get themselves into.  You will likely have some frustrating nights where your little one will drive you a little batty with their babbling.

And although you can't fix the situation, you can make things substantially easier on both you and your baby. Adopting a bunch of quick-fixes to get your baby back to sleep is likely to end up creating dependencies that will last long past the time baby's figured out how to get themselves back to sleep. So please don't give in to the temptation to rock or bounce them to sleep, don't let them sleep in the swing, don't take them for car rides, and above all, don't nurse or feed them back to sleep.

Offer them some comfort, tell them it's still bedtime, help them get back into a comfortable position if they've gotten themselves pushed up against the side of the crib, or roll them onto their backs if they've flipped, but make sure to let them get back to sleep on their own. That way, once they've got this new skill mastered, they'll still have the ability to self soothe when they wake up at night.

It's likely to be a bit of a challenge, and it may feel at times like one skill gets mastered just in time for another one to start developing, but hang in there. The whole time this is going on, your baby is also developing the ability to consolidate nighttime sleep better. 

​So stay consistent, and you can expect even more of those glorious sleep-filled nights once the storm has passed.
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If you need more help navigating your baby's sleep regressions or help getting their sleep on track and you want a do-it-yourself approach then our expertly curated sleep training guides will give you the tools that you need to see success. Stop the endless Google searches and find all that you need in one place. 

Author

Erin Neri - Certified Pediatric Sleep Consultant and Owner of To The Moon and Back Sleep Consulting since 2016. 

Proud mother of 2 young school aged boys who did not come into the world  preprogrammed with independent sleep skills. 27+ years of training & experience working with children and families including her BA in Applied Psychology, Infant Mental Health Training, Early Childhood Education & Experience. Completed Integrative Feeding Specialist Certification in Oct. 2022. ​