If you’re a parent, you’ve no doubt heard about The Wonder Weeks, written by Xaviera Plooij, Frans X. Plooij PhD, and Hetty van de Rijt PhD. The book outlines the 10 “wonder weeks” during infant development (which often cause sleep regressions), that all babies go through in the first 20 months of life.
The book outlines when and why each “wonder week” happens; it also offers parents insights into how to help their babies navigate each wonder week, and turn it into a leap forward for baby. But, how do these mental leaps impact sleep? This article will provide a Wonder Weeks Chart outlining the impact to sleep based on my experience for over 15+ years as a sleep consultant. All views regarding how The Wonder Weeks impact baby and toddler sleep are ours based on experience and are NOT taken from The Wonder Weeks book. For full information on each Wonder Week, reference the Wonder Weeks book itself.
Here is how The Wonder Weeks impact sleep!
Wonder Weeks Chart: How The Wonder Weeks Affect Baby and Toddler Sleep
| Week | Name | Description | Impact on Sleep |
|---|---|---|---|
| 5 Weeks | Changing Sensations | Your newborn is “waking up”, becoming more alert, and noticing the world around her. This is understandably overwhelming for newborns! | This is when “the witching hour” usually starts – that period when your baby’s fussy from about about 5 – 10 or 11 p.m. Be available to cuddle baby often (wearing baby is a great idea at this time); you may also need to feed more frequently in the evening. Baby may also go through a growth spurt at this time. Finally, keep in mind that this Wonder Week overlaps a bit with the 6 week peak of fussiness. |
| 8-9 Weeks | Patterns | Baby is beginning to recognize and create simple patterns in his world; he’ll practice moving his hands in the same way over and over, or make the same grunting sound again and again. | All this curiosity and alertness can make it hard for baby to settle and fall sleep, so be sure to make your nursery sleep-friendly – it should be dim and quiet. This is also a great time to begin working on simple sleep time routines – start doing the same patterns of events at nap time and bedtime. |
| 12 Weeks | Smooth Transitions | Baby’s movements become smoother and more coordinated; baby also begins to recognize changes in her world, and the patterns of these changes (i.e. every time the dryer buzzer goes off, mom leaves the room). | Baby is getting squirmier at this age, and becoming more active – and that can mean changes to your sleep routine. Your baby may start breaking free of the swaddle. Some parents find that baby’s newfound ability to roll interferes with sleep – baby can roll from back to tummy, but not the other way around. Other parents notice that their babies settle into a semi-regular sleeping and feeding schedule at this age. But, don’t worry if your baby isn’t there, yet. |
| 15-19 Weeks | Events | Baby is learning to recognize cause and effect, and to predict outcomes (i.e. ‘If I drop this toy, it will fall to the ground, and dad will come and pick it up’). | Welcome to the 4 month sleep regression! If baby’s sleep was predictable up to this point, it may all fall apart now. Continue to work on building consistent sleep routines; this will help baby learn that certain events mean sleep is coming. You may also want to work on identifying any sleep associations baby may have; that will help with sleep training. There’s also another growth spurt that happens around 4 months. |
| 23-26 Weeks | Relationships | Baby begins to perceive distance at this point – the world becomes a much bigger place for her! This may be one reason why many babies begin rolling/crawling at this time. | Separation anxiety may become a problem at nap time and bedtime, since baby now understands that when you leave, you’re far away. This is also a great time to sleep train your baby – work on weaning your baby away from her sleep associations, and on helping her learn to fall asleep independently. Finally, there’s yet another growth spurt that happens around 6 months, for most babies. |
| 33-37 Weeks | Categories | Baby is learning that various things can be grouped together – for example, his blocks may all look different, but he recognizes that they are all blocks. Baby also makes big strides in mobility, learning to crawl well, to pull up to standing, and possibly to take assisted steps. | This Wonder Week coincides with the 8/9/10 month sleep regression. Baby’s sleep may be seriously disrupted, thanks to all his new-found mobility. But baby may also begin to experiment with cause and effect at sleep times – ‘If I cry, what will mom do?’ Your baby will quickly pick up on any patterns, so make sure not to create any new sleep associations at this stage. Finally, if baby is still waking to feed at night at this age, we usually recommend an attempt at night-weaning. (Oh, and P.S. – there is (you guessed!) another growth spurt to watch out for, around 9 months.) |
| 42-46 Weeks | Sequences | Baby begins recognizing the steps involved in simple tasks, like getting dressed, or making lunch. Baby can also apply this to his own tasks – socks have to go on before shoes. | Routines are so key at this stage; most babies love knowing what comes next, so work to continue strengthening your sleep routines. You may find that your baby goes through the brief 12 month sleep regression around this time, and tries to give up her morning nap; we advise that you stick to two naps for now, as most babies this age can’t manage with just one nap. |
| 52-55 Weeks | Programs | Your toddler builds on his understanding of sequences, and starts to learn that there is more than one way (or one “sequence”) to accomplish the same task. This is also when most toddlers start showing strong preferences (i.e. pink socks are great, but green socks are bad). | Welcome to toddlerhood, parents! At this stage, separation anxiety often comes back with a vengeance. You may also start to see some nap time and bedtime resistance at this point, as your toddler is learning to assert his independence and preferences. |
| 61-64 Weeks | Principles | This stage is related to the cause-and-effect breakthrough we saw in the 15-19 week stage, only now, your toddler is learning how to use cause-and-effect to achieve her goals. She is also learning that her actions have certain consequences | It’s time to talk about the D-word, parents – discipline. Your toddler is learning fast how you respond to her actions, so be sure that you are sending the right messages with your responses. This is the time to start establishing boundaries and setting limits for your toddler surrounding sleep, and enforcing them. We often tell parents that at this age, sleep problems are rarely sleep problems – they are discipline problems. |
| 72-76 Weeks | Systems | Your toddler is capable of understanding larger systems now – for instance, she knows that the procedures and expectations at daycare are different than those at home. Your toddler can also change her behavior and actions to suit different situations, which explains why your toddler may be sweet and helpful for the babysitter, but grumpy and whiny for you (which is not at all uncommon, by the way!). | If it hasn’t already, your toddler’s ‘toddler attitude’ may show itself full-force around this time. Continue to enforce your sleep time boundaries and limits. By 17 or 18 months, tantrums are common. Toddler tantrums at bedtime and nap time are especially frustrating – it’s key that you stand firm during these tantrums. Also, watch for the 18 month sleep regression that happens at about this time; it tends to be one of the toughest. |
This chart has been created by The Baby Sleep Site®. All views regarding how The Wonder Weeks impact baby and toddler sleep are ours based on over 15+ years of experience and are NOT taken from The Wonder Weeks book. For full information on each Wonder Week, reference the Wonder Weeks book itself which you can find on Amazon.
Whew – that’s a lot of information to take in, isn’t it? I hope this Wonder Weeks Chart has helped you learn more about your baby. But, if you’re struggling to make sense of all this, remember that you don’t have to make sense of it alone. Contact us at any time for real help and kind support!
My ten month old was taking half an hour to fall asleep for naps and at bedtime. When she was unwell I put her in bed with me to snuggle and she was asleep in 5 minutes. I’ve continued with it now she’s well because she goes to sleep so fast and doesn’t fight it. Once she’s asleep we move her to her cot. It’s really working for us but I worry it may mean she’ll have trouble falling asleep on her own down the track. She is also still waking for a bottle through the night. In the last month it’s reduced from two wake ups for a bottle to one so things have improved. Any suggestions for improvements?
Hi Karissa,
Thank you for visiting The Baby Sleep Site! In general, we like to say that if it’s working for your family and safe for everybody, stick with what you’re doing. Some families co-sleep for a portion of the night, and some for the entire night, but if you all feel like you’re getting enough sleep, and you’ve talked with your healthcare professional to make sure your sleeping situation is safe, then go for it. If your daughter starts waking when you transfer her, or you see increased night waking in general at any point, then you might want to start weaning away from co-sleeping at the beginning of the night, but this is not a problem every baby will have, so wait and see how it goes.
I hope this helps. Good luck!
My 8w old is going through the second leap and for about the past week he has been taking TERRIBLE naps; only sleeping btwn 10-30mins at a time before waking. He’s sleeping fine at night, but naps are a huge struggle. He doesn’t take too long to fall asleep, I’m sure he isn’t over tired. I also have been putting him down awake a lot and he’s falling asleep, but then he wakes up within a half hour! He’s in his dark room, swaddled with loud white noise. He definitely needs more sleep, if I pick him up he will usually fall right back to sleep, but again only stay asleep for a very short time. I do t know if this is just bad sleep from the leap or another problem entirely. He napped great before this- usually btwn 1-2.5h at a time. what do I do??!! TIA
Hi @Reagan – Thank you for writing to us! I’m sorry that this past week has been so tough for your little guy’s naps! Naps can be tough, and short naps can be very common! Keep offering many naps since they are so short, and encourage them to lengthen as you have been doing, and hopefully this will pass with this wonder week! This article on our blog should help too:
https://www.babysleepsite.com/baby-naps-2/short-baby-naps-explained/
Good luck Reagan!
Great post, Now every parent like to admit their baby into the baby development class. It’s most important to improve a baby’s mind and there are different baby sensory classes available like Bloomwellbeing.
You Are Most Welcome Christie! Love The Thumbprint Idea! Will You Have Them Sign Over Their Thumbprint? Just Curious…
My son is 15 months and will not sleep!!! He was doing great sleeping aroumd 8-9 hours all night then suddenly 3 weeks ago he stopped and now will not sleep hardly at all like a 180 change.. he will act tired amd go down around 10pm sleep till 12 am then stay up all the way till 10 am with no naps or nothing then crash for a few hours to do it again. Hes been super fussy and i cant leave the room without him throwing a fit or chasing after me which wasnt much like him before either…i dont know whats going on with him hes never acted like this or had this much of a hard time sleeping…any advice?
Hi Emmamae – Thank you for writing to us, and I am sorry that sleep has been so rough for you and your 15 month old! Being awake from 12am till 10am is brutal!! Since you mentioned it coming on suddenly, I would recommend checking in with your little one’s doctor, to rule out any illnesses or physical reason for this abrupt change.
If you get the all clear from his doctors, it may be time to really dive into his schedule to see what is going on. One of our expert sleep consultants would love to take an in depth look at his sleep history and details about his day and night sleep and can help with 100% personalized and customized help. She would want/need to look at the whole picture to find out why his sleep regressed so badly and to then make a plan to help!
If you find that you would like more help, you can read about all of our sleep consultation packages here: https://www.babysleepsite.com/services/
Hang in there Emmamae!
“It’s time to talk about the D-word, parents – discipline.”? Why you would punish any child let alone a baby is beyond me. And if you’re child is grumpy with you and not strangers it’s because they feel safe releasing those emotions. And that’s important.
Hi @Haley and thank you for stopping by the Baby Sleep Site. I apologize if you were upset by this portion of the article. The Wonder Weeks is a book (and app) that many parents today are using and we wanted to be sure to highlight how the big developmental changes covered in the book can affect sleep and behaviors of the child. We of course know that all parenting philosophies are different as well as all children, so we try to cover the bases and provide information that each family is welcome to use and decide what works best for them. 🙂 By “Discipline” we just mean setting some limits for the child in order to protect their sleep, not punishing them (you can see our suggestions in this article: https://www.babysleepsite.com/toddlers/limit-setting-toddler/). We understand they are young and figuring out life so being grumpy and pushing limits is an important part of the process and I definitely agree, should not be discouraged, but often they need some guidance. I hope that provides more clarity where the article was coming from. Thanks for adding to our discussion!
Hi there,
I’m just wondering if you recommend starting to sleep train during one of the wonder weeks? My son is just over 9 months and I normally nurse him to sleep. He usually naps really well (twice a day for an hour and a half), and up at night only once or twice. We’ve just started the 7th leap and he is definitely sleeping way worse. He’s pretty much refusing to nap so I feel like the only thing I can do is let him cry for a while. I’ve read lots about sleep training so I feel like I know what to do, I just haven’t wanted to listen to him cry ye. And now I’m just not sure I should be starting during this leap. Any advice? Thanks!
Hi @Lauren, thanks for writing to us! I loved using the Wonder Weeks with my kids – it explained so much at times, so I’m glad you are using that handy tool. There are definitely better times to start sleep training than others, and we do usually recommend to try to wait past a sleep regression (there is one around the 8-10 month mark which coincides with the leap) to see if things even out on their own. Here is an article with the ideal windows and tips for if/when you try: https://www.babysleepsite.com/sleep-training/baby-sleep-training-best-time/
Hang in there! I hope things get better for you guys again soon!
Hi, my daughter is 28 weeks old and we can’t get out of her sight without her instantly crying (crying hard at times). Even if she is playing with toys on the floor and we are in the same room if we aren’t holding her or on the floor with her she is crying. Just all of a sudden super clinging and just doesn’t seem happy at all. Any advice or words of wisdom?
Thank you!!
@Nacaela I’m sorry to hear this! It sounds like your daughter is experiencing some separation anxiety, which is very common at this age. You might be interested in this article we have on this topic: https://www.babysleepsite.com/sleep-training/baby-toddler-sleep-separation-anxiety Hope this helps and good luck!