Dealing with cranky kids is rough, but if you want to take those extra fussy baby days in stride then knowing baby developmental leaps is essential!

We’ve all been there. Our sweet little squish is the calmest and cool kid ever… until they’re not. You wake up one day, or more likely night, to cranky cries that aren’t easily soothing. What gives? Chances are, it’s one of the baby developmental leaps. Keep reading for details, and how to make the process a little smoother.

baby developmental leaps

Baby Developmental Leaps and The Wonder Weeks

So you’re baby is not hungry and has had plenty of breastmilk or formula. Not teething. The diaper is clean. They’re swaddled just like they always liked. Even the favorite swing isn’t working!

Chances are your baby is smack dab in the middle of one of their baby developmental leaps.

The absolute greatest hack a mom can have in the toolbox of hacks is knowing about baby developmental leaps, when they are, and how to deal.

There is a totally free app called Wonder Weeks that keeps you up to date as your baby grows, and there’s also a book!

But here are the basics to get you started.

All babies’ brains develop at a fairly predictable rate. At certain points throughout their first year or so of life, statistics can tell us when they will make huge steps forward in their development.

This is the developmental leap, also just called a leap. The point in time when your baby leaps forward in their development pretty rapidly.

It’s pretty disorienting.

When babies are first born their skills and ability to comprehend the world around them is almost nonexistent.

With each leap, they become more and aware of the world around them, who the people are they are, and they begin to form their own identity.

Imagine one day you just woke up and realized for the first time that you are a different person, a separate being, from your mother. That would be pretty freaky if up until then you just kind of felt melded with her, right?

Needless to say, one of the main reasons for this crankiness is just baby getting used to their new reality every time a leap happens.

So how do you deal with it? How do you keep your sanity, while helping your baby make these transitions?

The most important thing is to know when it is going to happen and that IT WILL END.

My kids all have woken frequently in the night, but usually, they just have a little milk and fall back asleep. They also fall asleep fairly easily. No colic. Except for one time…

The four-month leap. This one is a doozy. My twins would just cry and scream for like 20 minutes at bedtime every single night during their period. Nothing soothed them!

But I was able to just go with the flow and not allow it to stress me too much because I knew why it was happening and that it would end soon.

(Of course, use your intuition and if you feel like something so really wrong, of course, talk to your doc.)

So read the book, download the app, and prepare yourself. And keep reading for answers to some of the biggest faqs with baby developmental leaps.

Knowing when the baby developmental leaps happen is a game-changer, but don’t forget to be prepared to ratchet up your patience a few notches.

What is a developmental leap in babies?

As babies grow and develop they reach certain points where they surge ahead in progress. These are called baby developmental leaps.
According to the Wonder Weeks, “all babies go though the same changes in the mental development at the same time. This is called a mental leap. With each leap, your baby is given the possibility to learn new things.”

What ages do babies have leaps?

There are 10 baby developmental leaps that happen at various points from birth up to around 17 months. The ages of the baby developmental leaps are:

Week 1 – around 5 weeks
Week 2 – around 8 weeks
Week 3 – around 12 weeks
Week 4 – around 19 weeks
Week 5 – around 26 weeks
Week 6 – around 37 weeks
Week 7 – around 46 weeks
Week 8 – around 55 weeks
Week 9 – around 64 weeks
Week 10 – around 75 weeks

How long does a developmental leap last?

The length of baby developmental leaps can varies from about one week up to a month or more! According to the Wonder Weeks, leaps aren’t all tears and fussiness though. It is typically broken into two phases, a fussy phase and a skills phase. But most parents really just want to know when that fussy phase will happen and when it will end because it ain’t fun.

How do babies act during a leap?

During baby developmental leaps, most babies will become fussier, grumpier, cry more, their sleep will be off, or they might just seem off like they aren’t their usual self, but they aren’t sick.

Do baby leaps affect sleep?

Baby developmental leaps can affect sleep. Ever heard of the 4 month sleep regression? That happens during leap 4. Babies might be more restless or harder to get to sleep during a leap. They might also skip or shorten naps during this time. But hold on parents! It does end.