Skip to Content

Leap 4: The Wonder Weeks Mental Leap at 4 Months Old

Share this post with your friends!

We are knee deep in The Wonder Weeks’ fourth mental leap and cannot believe the change in our baby over the last couple of weeks. We sailed through leaps 1-3, with hardly any fussy periods whatsoever, but leap 4 has really come to bite us on the butt. Our sleepy and content newborn son has disappeared and in his place is a clingy, fearful and fussy 4 month old baby who will fight sleep with every fibre in his body.

What are The Wonder Weeks Leaps?

Incase you were wondering, The Wonder Weeks is a book and an app revered by Mums all over the globe, because it finally gives us an insight into our baby’s fussy periods and helps to understand how we can better help them to learn, develop and begin to understand the world around them.

The Wonder Weeks is a worldwide best seller detailing the mental development of babies. Wondering why your baby suddenly seems fussy or doesn’t want to sleep after weeks of being content? Then consult The Wonder Weeks app by inputting your baby’s due date and you’ll have all the information to hand at the touch of a button.

Some people think mental leaps are a load of woo, but I disagree. The app has been spot on for both my boys and has given me incredible peace of mind when I’ve thought I was parenting wrong, only to discover they are ‘leaping’ and after a few days/weeks, everything is back to normal…for now.

Buy The Wonder Weeks book on Amazon: Available as paperback or Kindle!

Felix lying on bed wearing vest which says 4 months old

Related Post: The Joy of Leap 6


What is Leap 4 and What Have We Been Experiencing?

Wonder Weeks Leap 4 is a biggie. Whereas the previous three leaps only lasted a week or two, leap 4 lasts an incredible five weeks and boy, doesn’t it feel like the longest five weeks ever?! Leap 4 is all about your baby learning about the events around him and we’ve seen such a huge change in Felix since her entered this leap.

The cool stuff

  • Rolling from front to back
  • Attempting to roll from back to front
  • Looking around the room for you when you move around cleaning
  • Grabbing toys and studying them intently
  • Reacting to his mirror image with giggles

The not-so-cool stuff

  • Fighting naps by pulling the dummy out of his mouth, kicking his legs and thrashing
  • Waking up at 4am to sing (extra milk before bed is not helping)
  • Becoming extremely impatient when hungry- I want milk and I want it NOW
  • Waking up as soon as you try to leave the room, whether he’s been asleep 5 minutes or 50 minutes
  • Needing to be able to see you at all times, otherwise crying
  • Feeding more regularly (only a pain because it means more bottles to wash and sometimes he wants his milk every two hours instead of three and I’m not prepared!)

So, with all of the above in mind, how are we feeling with only one week left to go of wonder weeks leap 4? You know what, I don’t feel too bad considering.

Our Experience with Leap 4

I know I am super lucky with regards to the 4 month sleep regression that on the whole, Felix is still technically sleeping through the night. Okay, so he’s not doing the 12 hours he was doing previously, but 7pm-4am is still pretty good going. Oh yeah, and I’ve tried to put his bedtime later, but when he’s ready for bed, he’s ready for bed- once he’s done fighting it of course!

Felix sat on sofa in the caravan at Wemyss Bay Holiday Park

I love that he is learning new skills such as rolling over and being able to grab onto toys. He is a bit further behind than Dex was at this age- Dex was already rolling both ways and was sitting in a high chair comfortably. Felix on the other hand has only rolled front to back a few times and can’t quite manage back to front yet.

Putting him in the high chair just feels totally bizarre as he can’t sit properly yet and seems so slumped. I can’t believe we will be weaning him in less than 7 weeks…we have discussed perhaps holding off for a couple weeks longer than 26 weeks as he was two weeks early, but I guess we’ll just see how he’s doing when we get there.

I am definitely looking forward to leaving this leap so we can get back to a bit of normality with naps and stuff. I have no problems whatsoever sitting and lying with him for naps because it means I get to catch up on Netflix, (you can check how to watch unavailable movies online), but I don’t think my husband is best pleased about the state the house is in and on days when Dexter is not in childcare, Felix barely gets a nap at all as I just don’t have the time to sit with him while he fights his sleep.

I’ve been trying more lately to get us all out of the house, so at least then Felix can sleep in the baby carrier.

Buy The Wonder Weeks book on Amazon: Available as paperback or Kindle!


What Comes After Leap 4?

We’ve got a welcome three week break coming up once we hit the end of leap 4 on or around the 7th May before being ejected straight back into Leap 5 at the end of May- the world of relationships.

In the meantime, we’ll continue to do whatever we can to aid Felix’s sleep, keep giving him all the cuddles and attention he desperately craves and make sure he is getting plenty of exercise during his awake periods by doing tummy time and back time on his playmat. He is also really steady in his activity centre (weirdly steadier than Dex was at the same age)

Felix using the Infantino Prop-a-Pillar tummy time support in the kitchen smiling happily

Related Post: Infantino Tummy Time Support Toy

Meanwhile, wish me luck with my fussy 4 month old baby and pray wonder weeks leap 4 and the 4 month sleep regression comes to a finish sooner than predicted!

Want to know what’s coming next? Read my posts all about Leap 5, Leap 6, Leap 7 Leap 9 and Leap 10.

If you enjoyed this post, please consider pinning the image below, so others can find it too!

Going through Wonder Weeks Leap 4? It is a toughie! One of the toughest baby leaps in my opinion - especially when combined with the 4 month sleep regression! Read all about our experience of leap 4 and what we did to work our way through it! Say goodbye to the drama of mental leap 4 and look forward to welcoming back your bright and smiley baby! #leap4 #wonderweeks

Share this post with your friends!

Hayley | Devon Mama

Thursday 2nd of May 2019

Isn't it amazing how you get an insight into their development with Wonder Weeks? I love it! Fingers crossed for a lovely, plain sailing time through leap 5 now!


Thursday 2nd of May 2019

I think my baby has been going through leap 4 for 6 months ?? in all seriousness I understand how difficult naps are when a toddler is around and an overtired baby is its own worst enemy! Snoozeshade over the pushchair with the myhummy in there is the only thing that has worked for us during the day as he simply cannot stitch his sleep together when there is any kind of stimulation - this is something that has become worse as the weeks go on! My second also wasn't sitting at the same age as my first then within a week he was sitting very confidently, clapping, waving and saying Dada (damn him!) Becoming months ahead of his brother almost instantly! I hope you find what works for you guys regarding sleep and the house just isn't important! It's all about keeping your sanity right now! X