Fussy baby not sleeping well? Developmental leaps in the first year you need to know about!
Your baby’s first year is a rollercoaster ride. Just when you think you’ve figured things out, a new phase begins—often accompanied by a fussy baby who doesn’t sleep well. Here’s an overview of your baby’s developmental leaps in the first year!
During the first year, your baby will go through seven developmental leaps. After each leap, your baby will have learned something new. But with each leap often comes periods of fussiness, greater demands, and disrupted sleep.
Happens at the same age for all babies
In the first few months, these leaps occur more frequently and last from a few days to a week, sometimes barely noticeable. Later in the year, the leaps become longer and more intense.
🌟 SLEEP TIP: In the BabyNaps app, you can track your baby’s development and see how sleep is affected month by month—a super-easy way to stay on top of when the next leap or sleep regression is coming.
5 weeks: Leap 1 – The World of Sensations
At 5 weeks old, your baby goes through the first developmental leap, known as "The World of Sensations."
Three key points about this leap:
- Your baby’s vision improves. Senses become sharper, and your baby starts to notice more sights and sounds. These new impressions can be overwhelming.
- Your baby can stay awake for longer periods (around 60 minutes is ideal).
- Your baby’s organs and metabolism are developing.
Top tips for this leap:
- Hold your baby close if they’re fussy; just being in your arms often helps.
- Explore contrasts with your baby, like shapes, stripes, and angles.
- Talk to your baby to help them practice facial expressions and interaction.
When the leap is over: Within about a week
8 weeks: Leap 2 – The World of Patterns
Around the 8-week mark, it’s time for the second leap, "The World of Patterns."
Three key points about this leap:
- Your baby starts perceiving the world differently, from a whole to patterns.
- Their vision sharpens even more, and they begin small body movements, like discovering their hands.
- Communication develops, and your baby might respond to you with new sounds.
Top tips for this leap:
- Your face and expressions are the best entertainment for your baby!
- Try a baby gym with dangling toys.
- Encourage your baby to grip toys or your finger.
- Pay attention to how your baby reacts after activities—new impressions may tire them.
- Stay close; physical proximity is the best comfort if your baby is fussy.
When the leap is over: Within 1–2 weeks
12 weeks: Leap 3 – The World of Smooth Transitions
At around 12 weeks, your baby enters the third leap, "The World of Smooth Transitions."
Three key points about this leap:
- Your baby can now notice smoother changes in sight, sound, taste, and touch, like moving objects or fading sounds.
- Their range of sounds expands—they might blow raspberries or scream in new ways.
- Movements become smoother, and your baby enjoys more activity around them.
Top tips for this leap:
- Go for walks! A stroll is a sensory explosion of lights, shadows, and colors for your baby.
- Establish more structured routines and consider starting a sleep schedule.
- Respond to your baby’s new sounds to encourage communication.
- Provide plenty of closeness if your baby is upset or fussy.
When the leap is over: Within about a week
19 weeks: Leap 4 – The World of Events
At a little over 4 months, your baby’s development kicks into high gear with the fourth leap, "The World of Events."
Three key points about this leap:
- Your baby starts connecting a series of events using their senses.
- They discover their body, possibly rolling over after some frustration.
- Voice development continues, with squeals or high-pitched screams.
Top tips for this leap:
- Play peek-a-boo to reassure your baby you’re still there, even when out of sight.
- Use songs, rhymes, and toys that let your baby explore themselves in a mirror.
- Begin introducing new flavors and textures if your baby starts solids.
When the leap is over: Within 1–6 weeks
26 weeks: Leap 5 – The World of Relationships
At nearly 6 months, it’s time for the fifth leap, "The World of Relationships."
Three key points about this leap:
- Your baby starts understanding relationships between objects and distances.
- They begin noticing cause and effect, like pressing a button to turn on a light.
- Your baby starts connecting words and simple gestures to daily life.
Top tips for this leap:
- Ensure you get some rest, as this period can be intense for parents.
- Practice peek-a-boo to ease separation anxiety.
- Stick to consistent sleep routines to help with disrupted sleep.
When the leap is over: Within 1–5 weeks
8.5 months: Leap 6 – The World of Categories
At around 8.5 months, your baby enters "The World of Categories."
Three key points about this leap:
- They start comparing objects, like matching a picture to a real item.
- They explore how things work and love experimenting with textures.
- Your baby understands more than they can express—talk about what you see together.
Top tips for this leap:
- Encourage exploration, but expect clinginess during this phase.
- Use signs to show when it’s time to eat or drink.
When the leap is over: Within 3–6 weeks
10.5 months: Leap 7 – The World of Sequences
As your baby approaches 10.5 months, they go through the final leap of the year, "The World of Sequences."
Three key points about this leap:
- They begin to understand sequences, like how to dress or stack blocks.
- They learn that one action can lead to another.
- Your baby realizes they can ask for help.
Top tips for this leap:
- Keep your baby engaged with activities like stacking toys.
- Let them "help" with simple chores, like pressing a button.
When the leap is over: Within 3–7 weeks
That was your baby's developmental leaps during the first year. But hold on tight—there’s more to come! Around 15 months and 17.5 months, it’s time again. You can also learn more about developmental leaps in the book or app called Wonder Weeks.
Evelina Åkerberg
10 January, 2025
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