The myth of baby sleep regressions – what’s really happening to your baby’s sleep?

The 4 month sleep regression, the 12 month sleep regression, the 18 month sleep regression – what is happening?

Of course, any time your baby’s sleep suddenly seems to go pear shaped , you wonder what am I doing wrong? Having a neat little term like ‘sleep regression’ gets you off the hook – it’s not you, it’s your baby. It’s a sleep regression. It’s normal and common and it will pass.

The term ‘sleep regression’ sounds more helpful than the patronising label ‘accidental parenting’ which implies you have done something to create your wakeful baby but you are such a half-wit you didn’t even realize you were doing something ‘wrong’. It sounds much smarter too and even a little bit intellectual, as though you have done your homework about infant sleep.

But here’s the thing: your baby isn’t having a ‘regression’. Sleep isn’t a milestone – even though it certainly feels like an achievement when your baby starts snoozing for several hours at a stretch. By the way, ‘all night’ in infant sleep studies means five hours sleep in a row –not eight hours like an adult or twelve hours like some baby books will tell you. The real, measurable, important milestones that signal your baby’s actual development can influence your baby’s sleep, or lack of it. So, when your baby, who has been sleeping in peaceful bocks, suddenly starts waking more frequently, it usually means he is approaching a real developmental milestone – he is not ‘regressing’, he is ‘progressing.’

Developmental milestones can be physical (rolling, crawling, cruising, walking), emotional (separation anxiety) and neurological. Neurological milestones are outlined in ‘The Wonder Weeks’ , a book by Dutch researchers, psychologists Franz Plooij and Hetty Van Der Rit , who observed many children in their homes over a number of years. They describe the ‘wonder weeks’ as critical periods of development that change the baby’s perception of his world. For instance, at 26 weeks, babies start to perceive distance. This means that as you walk away, your baby is now more aware of the distance that separates you and he will yell at you because the increasing distance between you and him is confusing and a bit scary.

As babies approach any new developmental phase, their perception of the world changes so, although this can be just a blip on the radar for some babies, more sensitive babies will need extra reassurance and can become quite clingy or generally unsettled at these times.

Because babies process information during their sleep – circulation to the brain almost doubles during REM sleep – it’s perfectly normal for them to wake more often as they are approaching new milestones. For instance, at around four months (the four month sleep ‘regression’ that everyone is talking about), babies are becoming much more aware of the world – they are babbling (this is the beginning of language acquisition), exploring things with their mouth (soon that will include their feet too as they suck their toes), they are recognizing familiar people (and becoming anxious around strangers – separation anxiety is kicking in), many babies are starting to roll over so they wake because they have unintentionally rolled onto their belly and this has woken them. They are confused and upset because they really wanted to be sleeping but that tiny brain processing information has resulted in some extra ‘practice’ of their new skill. All of this adds up to a very busy little brain that finds it difficult to switch off. And, as well as often having difficulty getting to sleep in the first place or resettling after being woken by their busy brains and bodies, when he wakes, confused, your baby will call for help from the most important person in his world – you.

Of course at any time if your baby suddenly becomes unsettled or wakeful, it’s important to check that there isn’t a medical reason for this or an impending illness such as sore ears or a urinary tract infection (babies generally wake when they wee if they have a UTI because it hurts), or if your baby has recently started family foods she isn’t upset by food sensitivities.

Once you have ruled out illness as a reason for sudden changes in your baby’s sleep patterns, consider your baby’s development: what new skills is your baby learning? Is she a bit more clingy during her awake times? Does she seem more sensitive right now? And try to see her wakefulness as a positive – she is not regressing, she is progressing. She is learning and developing in leaps and bounds. She isn’t waking because you have done anything wrong. You aren’t encouraging ‘bad habits’ you are helping your baby feel secure as she grows through these intense developmental stages. You don’t have to justify your baby’s behavior with fancy labels or reasons for her waking (except perhaps, to yourself if it makes you feel better).

The good news is that, as your baby masters each new milestone, there will be spells of sound sleep again – until the next developmental leap!


Pinky McKay is an International Board Certified Lactation Consultant and best selling author of Sleeping Like a Baby, 100 Ways to Calm the Crying, Parenting By Heart and Toddler Tactics.  For more baby sleep tips, check out her bundle - Sleeping Like a Baby plus the recording package of interviews by leading international sleep researchers ‘The Truth About Infant Sleep – Science, Wisdom and Gentle Solutions’ 




  1. Joanne Says Reply

    My 20 month toddler used to be a sound sleeper (7h in a row) at the 1 year mark but it’s been a while since I’ve had any sound sleep. Correspondingly, it’s almost like she’s on a developmental highway. Is this to be expected or should there be breaks between her developmental milestones?

    Looking forward to a period of respite.

  2. Anna Says Reply

    Hi Pinky,
    Thank you for writing this article. It is exactly what I needed to read now to bring me back down to earth. Your articles are the only ones I find that align with my values and they always provide me with reassurance of my parenting choices. I read a few other articles before this one and all felt was “doomed” for at least the next month. Now I have a better understanding that my bub is not trying to GIVE me a hard time, she is HAVING a hard time and I need to support her through that!

  3. Ha ha! The Universe (Temporarily) Hates Me / Melissa Coursey Hess Says Reply

    […] “See you soon!” I whisper.) Some people call this the four month sleep regression, but I prefer this perspective. It’s a process and I’m looking forward to getting some longer stretches of sleep […]

  4. rebecca Says Reply

    Hi Pinky.

    I needed this article this morning. I have no idea how I managed to find it or stumble across it but it’s just opened only browser and I read it out if curiosity. My daughter has spent the last couple of nights seemingly not wanting to sleep all of a sudden. Every other `regression` so far has never been as bad and we know that her gums are bothering her.
    But this morning, I’ve had 2hrs sleep. Popping in and out of bed non stop all night, she would only sleep on me. The minute she wasn’t in contact with me, BOOM! Wide awake. Saying that, she’s 6m and we’ve been told it won’t be long until she starts talking, she’s attempting to crawl (albeit backwards) and she’s just started rolling off her tummy now. I feel a lot better about my lack of sleep thanks to you and this article. Thank you!!!

  5. Mindy Says Reply

    My 15 month old daughter has NEVER slept through the night. Not once in her life. She wakes up 4 to 6 times every night. She’s breastfed, but so was her older sister who slept decently well from fairly early on. It’s extremely frustrating. It’s very hard to function with too little sleep for well over a year now.

  6. Sarah Says Reply

    My daughter is EBF and she is 10 months old and has always woken up every 2 hours and still to this day is waking up every 2 hours….. Am i doing something wrong?

    • Marie Says Reply

      It’s common for babies to wake often, even at 10 months. Some are just better sleepers than others. My 14 month old still wakes up on average about 3 times a night. He either wants to nurse or be comforted back to sleep. It will get better with time. Hang in there!

    • Mariana Says Reply

      Sarah my 17 month old has nerver and i mean never slept through the nite. I often feel like im doing something wrong … I breast fed until just two months ago. she needs me to fall asleep and then still wakes . its rough and kicking my butt….. so you are not alone….

  7. Nicole Says Reply

    This article is totally patronizing, just like every other article on sleep I’ve read. Isn’t it possible to be encouraging without insulting our intelligence as parents?

    • Emily Says Reply

      Agreed. Don’t insult my intelligence because I believe one thing or another. I definitely won’t be coming back to this site for parenting advice.

    • Karen Says Reply

      I agree. Luckily the patronizing tone was not continued throughout the ENTIRE article or the message may have been lost completely.

  8. amber Says Reply

    Actually I don’t think she meant to be patronizing at all. Didn’t you read the article? Shes trying to change your word usage because it connates negativity. When in fact what’s going on is positive. I find reading articles like these are very helpful during the challenges of raising our children. When you look at things in a positive manner it helps to not be overwhelmed or stressed with the situation. Words are thoughts are very powerful. I enjoyed this article.

  9. CURSE YOU, NEPTUNE! | the mom cha-rod Says Reply

    […] typed “12 month sleep regression” into the google machine, and this was the first website on the list. I really liked what…Pinky (is that her real name?) had to […]

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