Developmental Leaps

Developmental Leaps

Apr 7, 2022
7 min read

In this article:

  • What are developmental leaps?
  • How do developmental leaps affect babies?
  • Signs your baby is in a leap
  • How long do developmental leaps last?
  • How you can help your baby during a leap
  • Toddlers and developmental leaps

Before I had my eldest I had never heard of a developmental leap. Soon I was listening to mums talking about their little one being in a ‘leap’ and how difficult it was. I had no idea what they were talking about. 

Fast forward a little through a lot of Google searching and I came across The Wonder Weeks. I entered a whole new world of leaps, fussy periods, “the three C’s” and learned a lot. 

The great news is that if your baby is in a great routine, developmental leaps tend to be easier to manage. Our Little Ones App will help make sure you and your little one are on the right track with daily nap and feed schedules designed for your baby’s specific age. 

In this article we are going to explore what developmental leaps are, if they affect your little one’s sleep  and how you can navigate these periods. 

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What are developmental leaps?

You may have been in the same situation as me, listening to others talking about “leaps” or “developmental leaps” and nodding along wondering what they are talking about. Well fear not, soon you’ll be an expert on them. 

Quite simply, a developmental leap is a period of intense mental development that your baby experiences. 

According to The Wonder Weeks babies will experience 10 leaps during their first 20 months of life which are linked to their actual age. Their actual age is based on their due date rather than the date they were born.

How do developmental leaps affect babies?

So what is the big deal about these leaps? 

During this time your baby has a lot going on. Their brain is so busy learning new skills, taking on more information and making major mental developments that it is bound to have a knock on effect. 

While your baby is in a leap you may notice a change in one or more of the following:

  • Mood
  • Sleep patterns
  • Health
  • Intelligence
  • Feeding


The Wonder Weeks talks about an increase in the three C’s during a leap. These are:

  1. 1. Crankiness
  2. 2. Clinginess
  3. 3. Crying

If you notice a big shift in your baby’s temperament then it is likely they may be going through a developmental leap. Their mind is doing extraordinary things right now and their world is changing. This is hugely daunting for a small baby who is learning to make sense of the world. 

Imagine if tomorrow you learnt that aliens lived among us or that you had the ability to fly. Your whole understanding of the world and what you thought you knew has been thrown into turmoil. You’d have to learn how to make sense of this ‘new world’. This is what your baby does at each leap; their perception of the world changes and they have to adjust to the new norm. 

During this unsettling time your baby wants to feel safe and secure, which is why they may be more clingy than usual. 

While we may be starting to understand why our baby is crying more, not wanting to be put down or being just constantly grumpy, it doesn’t always make it easy to manage. Their mood swings can be tough on parents too. 

Don’t be afraid to ask for help if you need it. Invite a friend or family member over to entertain your little one and give you a break or try venturing out for some fresh air. Lots of babies enjoy being out and about, seeing new places and faces. It also helps to break up the day for you.

Remember this won’t last forever.

Sleep patterns

Not only has your happy baby suddenly had a personality transplant and turned into a misery but now you’re noticing a shift in their sleep routine. Don’t panic! 

Your baby’s brain is developing rapidly during their leap which can take its toll on their sleep. 

This might look like:

  • Resisting their naps or bedtime  - they can find it harder to wind down meaning they need a longer wind down time before a sleep.
  • Waking for extended periods during the night - your baby may wake more or for longer overnight to practise new skills they are trying to master during this leap.
  • Waking early in the morning - try to ensure your room is promoting sleep and reinforce that it is time to sleep by keeping them in their sleep space all the while they are happy.  
  • Wanting to feed more overnight - this may be because they aren’t finishing feeds during the day or because they are using more energy during this leap, such as becoming more mobile.
  • Shorter naps - catnapping can be common during this time as babies can find it harder to link their sleep cycles.
  • More tired in the day - with all the extra mental stimulation they can seem to struggle with their usual awake times so you may need to reduce their awake times a little while they are in the leap.

It might be that you need to make some adjustments to your baby’s sleep routine during this time. Often these are short-term changes and once they are out of the developmental leap, their sleep pattern reverts to normal. 

It can be easy for new habits to creep in during this time. If your little one isn’t settling well it can be easy to help them get to sleep each time. However, once the leap is finished you can be left with a new sleep association such as co-sleeping, rocking or feeding them to sleep. 

If you’re struggling to wean your baby from this new sleep association then our Little Ones App will guide you through, step-by-step.


Although less common, some parents notice a deterioration in their baby’s health during a leap. The most common are:

If you notice a baby’s change in their health and you are concerned then do contact your doctor or health professional for advice.


So far it has seemed like a lot of negative changes. However, this is a positive. This is the reward for coping with all those negatives. You get to witness your baby learning, developing and changing before your eyes. 

As we know, developmental leaps are periods of intense mental development, so it can seem that you put your baby to bed one night and they learn to do something new come the morning. 

Here are some of the highlights you can expect:

  • Learning to smile
  • Holding their head upright
  • Rolling over
  • Looking for main caregiver
  • Holding toys
  • Waving
  • Playing peek-a-boo
  • Babbling and ‘chatting’ with you
  • Starting to role-play
  • Vocabulary improvements

It is a joy to witness this rapid progress and definitely helps to balance the scales a little more. 


You may notice that your baby suddenly seems less keen on feeding whilst they are in a leap. Being fussy when feeding, be this breastfeeding, bottles or solids can be common but tends to be short-lived. 

Your baby may:

  • Want to feed more frequently than before
  • Not be interested in feeds at their usual feeding times
  • Come on and off the breast or bottle, being distracted by what is going on around them
  • Take smaller quantities of milk, preferring to snack feed
  • Be fussy with solid food, even with foods they previously loved
  • Want to snack more if they are on solids and eat smaller meals

The best way to navigate this is to be consistent with your approach. 

  • Offer your baby their feeds; milk and solids depending on their age,  at the usual time. 
  • Try feeding them in a quiet space if they are easily distracted.
  • Make sure you are still getting lots of wet nappies and soiled nappies. If you notice a change in the amount of wet nappies you’re getting then consult your healthcare professional to rule out dehydration. 
  • If your baby is on solids then eat with them so they can mimic you eating.
  • Ensure they have a favourite food on their plate or try presenting the food in a different way such as making a picture with the food or using an ice cube tray as a plate.
  • Remain calm if they are being fussy, they won’t starve themselves. 

Signs your baby is in a leap

Maybe your little one seems out of sorts and you’re wondering if they are in a leap. It always feels more manageable when you know the reasons for a change in behaviour or routine. 

Here are some signs that your baby is in a leap:

  • Increase in the ‘three C’s’: crying, clinginess and crankiness
  • Change in sleeping patterns
  • Their mood is more unpredictable
  • Existing skills improving
  • Learning new skills
  • Separation anxiety
  • Change in their health
  • Fussiness when feeding

If you suspect your baby is in a leap you can track this using The Wonder Weeks app which is based on their due date. 

How long do developmental leaps last for?

While it can feel like your baby’s leap will never end, the good news is it will. 

Developmental leaps vary in length. The shortest leaps are just a week long and the longest are roughly five weeks. Yes, that does sound very long! However, you often find that there will be peaks and troughs during the long leaps. Some days you wouldn’t know they were in the middle of a leap and other days, you definitely know!

Remember on the tough days that as they say, this is just a phase and this too shall pass. 

How can you help?

The biggest way you can help your baby during this phase is to keep in mind it is just a phase. Your baby isn’t broken, they’re just going through a lot right now. 

  • Stay calm, leaps are a good thing, it means your baby is learning and developing
  • Enlist some help if you need a break
  • Try to stick to your usual routine where possible
  • Avoid introducing new sleep associations
  • Play games like peekaboo to help your baby develop object permanence, this reassures them that you always return
  • Give them more physical contact, skin to skin can help
  • Use a sling to keep them close by whilst keeping your hands free

Toddler developmental leaps

Congratulations you and your baby have successfully made it through the ten developmental what now? Do they no longer have intense periods of development? Is it smooth sailing from now on?

Unfortunately, no. Your toddler will still have periods of rapid mental and physical development. The good news is that now that they are a toddler they can understand you more so communicating with you is easier.

The bad news is that they are still an irrational toddler at times who doesn’t want to listen to you! The positive is that toddlers are a lot of fun. With each developmental milestone they reach you will enjoy more with them and see their personality coming out. 


Developmental leaps can be tough on babies and parents, however, we can see that they are a normal part of a child growing up and learning. By reaching these leaps it can be reassuring that your baby is meeting their developmental milestones. If you are ever concerned that your baby isn’t meeting their developmental milestones then do contact your healthcare provider to discuss this. 

Developmental leaps can affect your child in various ways throughout their leap but rest assured, these changes are often temporary. If you find that after a leap your baby’s sleeping pattern doesn’t return to normal or you’ve ended up with a sleep association our Little Ones App will guide you and your little one to get back on track. 

Bibliography and Further Resources

Age-Related Developmental Milestones (2022, March 3). The Observant Mom.

The Wonder Weeks | A smart start for a happy beginning! (2022, March 30). The Wonder Weeks.

The Wonder Weeks - Marco Plas, TEDxGlasgow

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