If you’ve ever found yourself staring at the baby monitor at 2am wondering why your previously good sleeper has suddenly started midnight gymnastics practice, you’re not alone. Almost all my clients have come across a blip at some stage. And it’s often because a developmental milestone is in play.
As both a mum and a sleep consultant for coming up to 10 years, I’ve come to one unavoidable conclusion: babies are wonderfully complicated little humans.
I always get a giggle from actor Matthew McConaughey’s famous quote about newborns, because he makes it sound so simple: “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.”
In theory, he’s not wrong. A newborn baby’s basic needs are fairly simple. They need to eat, sleep, and have their nappies changed. The tricky part is figuring out exactly which need is causing the problem at any given moment (and don’t discount wind at these younger ages either).
But when your older baby is suddenly waking more often, fighting naps, or treating bedtime like a social event, many parents naturally wonder whether a developmental milestone could be the culprit. Do developmental milestones really affect sleep?
The short answer?
Yes. Developmental milestones can temporarily affect sleep.
The even better news?
It’s usually a sign that something exciting is happening in your baby’s growing brain and/or body. Trust me, it IS a good sign!
Why developmental milestones can disrupt sleep
Sleep can get disrupted because babies don’t learn new skills during business hours only.
When they are mastering rolling, crawling, pulling to stand, cruising, walking, or talking, their brains are working overtime. These new skills often become so exciting that babies want to practice them everywhere. At all times.
Including at bedtime or 3am. Which is going to disrupt their sleep.
Researchers have found that periods of rapid development can be associated with temporary sleep disruption. A 2015 study on infant sleep and motor development during the transition to crawling found that babies experienced more extended night wakings around the time they learned to crawl.
The researchers concluded that emerging motor skills may be linked to periods of disrupted sleep as babies adapt to their new abilities.
In simple terms, learning something new takes a lot of brain power. So, it’s only natural that sleep can occasionally become a little messy while that learning is taking place.
The midnight practice sessions are real
One of the most common things parents tell me is:
“Every time I go into her room, she’s standing in the cot.”
Or:
“He’s rolled onto his tummy and now he’s angry about it.”
Or my personal favourite:
“She’s sitting up in the dark chatting away to herself.”
As amusing as it can be, these situations are incredibly common.
When babies discover a new skill, they become fascinated by it. Much like adults who discover a new app, hobby, or gadget and suddenly can’t stop talking about it, babies want to repeat their new achievement over and over again.
Rolling.
Crawling.
Pulling up.
Babbling.
Standing.
They are practicing because that’s how learning happens. And the cot is a perfect place to practice. Unfortunately, they don’t yet understand that bedtime is not the ideal time for rehearsals.
What about teething?
Teething is often blamed for every sleep disturbance between four months and four years. I’ve written about teething before. But because it can also disrupt sleep, I’m adding it here too.
While teething may not be responsible for every rough night, research does suggest that teething can cause some temporary sleep disruption. You’re NOT imagining it.
A study published in Pediatrics found that babies experienced increased wakefulness, irritability, drooling, gum rubbing, and fussiness during the days immediately surrounding tooth eruption.
If your baby’s gums are sore and uncomfortable, it’s understandable that they may struggle to settle or stay asleep. No one can be expected to sleep through pain.
However, it’s important to remember that teething discomfort tends to be temporary. Months of disrupted sleep are rarely caused solely by a tooth trying to emerge. There, I said it.
Things often get worse before they get better
One interesting finding from developmental research is that progress is not always linear. Things can get worse before they get better.
As babies learn new skills, there can be a temporary period where sleep, behaviour, and emotional regulation seem to take a step backwards before moving forwards again.
Think of it as your baby’s brain going through a renovation. Things might look a little chaotic while the work is being done, but the finished result is worth it. Truely.
The biggest mistake parents make during milestone disruptions
When sleep suddenly falls apart, most parents understandably go into problem-solving mode. But this is when so-called “mistakes” can happen:
You start changing up bedtime. Add extra feeds. Rock more. Drive around the block. Bring baby into your bed. You try absolutely anything that might result in everyone getting a few more hours of sleep.
I get it! Anything for a bit more sleep.
The challenge is that while developmental milestones are temporary, some of the habits we introduce to survive them can stick around much, much longer.
If your baby suddenly starts needing to be rocked, fed, bounced, or driven to sleep every time they wake, those sleep associations, or sleep props, can remain long after the milestone has passed. And that’s when you can have a problem.
What should you do instead?
The best advice I can give is surprisingly simple: stay consistent. Same routine, same bedtime phrase, same response.
That doesn’t mean ignoring your baby or refusing comfort. In fact, your little one may genuinely need some extra reassurance during this phase.
Of course you can:
- Offer comfort and reassurance.
- Help them lie back down if they are stuck standing in the cot.
- Roll them back if they are upset after rolling.
- Respond to genuine discomfort.
- Keep your bedtime routine predictable and familiar.
- Make bedtime a little earlier if they are more tired than usual
What you want to actively avoid is introducing any new sleep habits requiring external help, that you’ll later need to undo.
Your goal here is to support your baby through the developmental leap while preserving the independent sleep skills they already have. That way they’ll be back on track in no time!
The good news
There is good news! Developmental milestones are temporary.
Your baby will eventually master rolling. They’ll figure out crawling. Standing will become old news. The endless midnight babbling sessions will slow down.
At the same time, your baby’s sleep is naturally maturing and consolidating as they grow (as long as there are no sleep prop issues in the picture).
So, if you’re currently navigating a milestone-related sleep wobble, take heart.
Stay consistent. Offer support. Keep your expectations realistic.
And remember that while it may feel like one milestone ends just in time for another to begin, every new skill is a sign that your baby is developing exactly as they should.
You have grown an amazing (yet complicated) little human, not a robot. Not every night will be the same, even once you’ve worked on sleep. BUT, if you can stay consistent, you’ll know when something is up when sleep goes awry. And you’ll then get your great sleeper back after the fact.
In other (more eloquent) words…The storm will pass, and those beautiful stretches of consolidated sleep are still waiting on the other side.
Have you been through a developmental leap, then got stuck needing to rock, co-sleep or feed back to sleep (when you never wanted to)? Book a FREE initial call with me HERE for a free mini-sleep evaluation and find out how my sleep packages can get your baby or toddler sleeping through the night (despite the odd blip).
References
Adair, R., Zuckerman, B., Bauchner, H., Philipp, B., & Levenson, S. (2000). Symptoms associated with infant teething: A prospective study. Pediatrics, 105(4), 747-752.
Atun-Einy, O., Scher, A., & Kuint, J. (2015). Infant sleep and motor development during the transition to crawling. Monographs of the Society for Research in Child Development, 80(1), 89-104.