If you have ever searched for "the wonder weeks sprongetjes" you are not alone. Sprongetjes is the Dutch word for the developmental leaps at the heart of the Wonder Weeks concept, and parents around the world use both terms to describe those sudden, stormy patches when a previously settled baby turns fussy, clingy, and hard to read. Understanding what is actually happening in your baby's brain makes those weeks feel far less overwhelming.
What Are Wonder Weeks and the Developmental Leaps?
Wonder Weeks is a concept developed by Dutch researchers Hetty van de Rijt and Frans X. Plooij, first introduced in their 1992 book The Wonder Weeks. Their research proposed that babies move through 10 major developmental leaps in the first 20 months of life. Each leap involves a significant shift in how your baby perceives the world, processes information, and learns new skills.
The word sprongetjes simply means "little jumps" or "little leaps" in Dutch. It is the original term from the research, and many parents still search for it when they first discover the concept.
The leaps are numbered one through ten and are timed from your baby's due date, not birth date. That timing matters for premature babies especially. The Wonder Weeks app and book both adjust for this.
What Happens During a Leap?
Just before and during a leap, many babies show a cluster of behaviours that can feel alarming if you do not know what is driving them.
- More crying or fussing than usual
- Wanting to be held constantly
- Disrupted sleep, shorter naps, or more night waking
- Feeding more frequently
- Clinginess and separation anxiety
- Loss of appetite in older babies
These phases are sometimes called the three Cs: clingy, cranky, and crying. They are temporary. Once your baby moves through the leap, you often notice new skills appearing, a broader attention span, or a shift in how they interact with you and their environment.
Not every baby shows every sign, and the intensity varies. Some babies sail through certain leaps with minimal fuss. Others find particular leaps harder. Both are normal.
The 10 Leaps at a Glance
Each leap is linked to a specific type of perceptual or cognitive shift. Here is a brief overview, timed from the due date.
- Leap 1 (around 5 weeks): Your baby begins to notice more sensations and stimulation.
- Leap 2 (around 8 weeks): Awareness of patterns, including familiar faces, grows.
- Leap 3 (around 12 weeks): Smoother, more deliberate movements emerge.
- Leap 4 (around 19 weeks): Your baby starts to understand simple events and sequences.
- Leap 5 (around 26 weeks): Relationships between things, such as cause and effect, become clearer.
- Leap 6 (around 37 weeks): Categories form. Your baby begins to group things by type.
- Leap 7 (around 46 weeks): Sequences and simple plans develop.
- Leap 8 (around 55 weeks): Understanding of programmes, or how a series of steps leads to a goal, deepens.
- Leap 9 (around 64 weeks): Your baby starts to grasp principles and rules.
- Leap 10 (around 75 weeks): A sense of systems and how things work together begins to form.
The Raising Children Network has detailed, evidence-based guides to developmental milestones at every age, which pair well with the Wonder Weeks framework if you want a broader picture of what to expect.
Practical Ways to Support Your Baby Through a Leap
There is no shortcut through a leap. But there are things that genuinely help.
- Respond promptly to crying. You cannot spoil a young baby, and fast responses build trust.
- Offer extra contact. Babywearing, skin-to-skin time, and lots of holding are all valid strategies.
- Keep the environment calm and predictable where you can. Loud, busy environments can amplify overwhelm during sensitive periods.
- Adjust your expectations for sleep. A leap-related sleep regression is not a sign something has gone wrong. It usually passes.
- Give yourself a break. Fussy periods are exhausting. Lean on your support network.
Sleep disruptions during leaps are real, and setting up the sleep environment well from the start helps. If you are unsure whether your cot bedding is fitted correctly, our guide on getting a snug and safe cot sheet fit walks you through what to check.
Safe Sleep During Fussy Leap Periods
When babies are unsettled, the temptation to add comforting items to the sleep space can be strong. Keep the cot clear. Red Nose Australia recommends nothing in the sleep space for the first 12 months, with soft toys and comforters not introduced before at least 7 months.
For wrapping during early leaps, Red Nose recommends lightweight cotton or muslin wraps. Stop wrapping at the first signs of rolling or at 3 months, whichever comes first. If you are comparing wrapping options, our article on swaddle wraps versus nursing covers versus blanket wraps covers the key differences clearly.
For dressing your baby to sleep during a leap, trust your feel rather than relying on a thermometer. Dress baby as you would dress yourself for the same room. Keep their head and face uncovered. Feel their tummy or back to check warmth. Cool hands and feet are normal. If baby feels hot, sweaty, or clammy, remove a layer.
Is the Wonder Weeks Approach Evidence-Based?
The original research by van de Rijt and Plooij has been debated in academic circles, with some researchers questioning the precision of the leap timing and the universality of the claims. That said, many parents find the framework genuinely useful as a way to reframe fussy periods as temporary and purposeful rather than random or alarming. Use it as a loose guide, not a rigid rulebook.
For a broader view of your baby's development, the Raising Children Network is a reliable, Australian-based resource with content reviewed by paediatric health professionals.
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