Wonder Weeks and Developmental Leaps: The Struggle is REAL!

Tips for how to best navigate through them
What to do and what not to do

Over the years, I have hosted numerous classes and private consultations and I often get questions about the sudden change in baby's behavior. The questions come in many forms, such as:

"What exactly are these 'Wonder Weeks' that everyone talks about?"
"What exactly IS this dreaded 4 month regression?"
“My baby was sleeping really well at night—going 5-6 hours stretches—and then all of a sudden she started waking up frequently and I can’t figure out what is going on.”

Sometimes an increase in wakefulness at night can be due to sickness or teething, but often this change in sleep pattern is due to a developmental leap—or what Dr. Hetty van de Rijt and Dr. Frans X. Plooij have called the Wonder Weeks.  Authors van de Rijt and Plooij have studied babies for over 35 years and they have discovered that babies go through eight developmental milestones in the first year of life (10 in the first 20 months!) right around the same week of life.

In this time, there is an increase in brain activity—think of it as your baby’s brain firing and wiring new neural pathways—which can cause a change in behavior.

What does it look like?

  • Increased wakefulness at night (sometimes happy and wakeful, sometimes fussy)
  • Clingy and cranky
  • Crying more than normal
  • Increased need to be fed (due to a wish for comfort)
  • Trouble napping or going to sleep
  • Change in ease of routine

When do these occur?

Unless your baby was born premature, most babies go through these developmental leaps at the following times:

  • 5-6 weeks
  • 8-9 weeks
  • 12 weeks
  • 19-20 weeks
  • 25-26 weeks (6 months)
  • 33-37 weeks
  • 43-47 weeks
  • 55 weeks (just after first birthday)

Why is this important to you as a parent?

At the early developmental leaps, your baby is noticing patterns, images, sensations and forming crucial relationships. As they get older (19 weeks and older) their developmental leaps coincide with a movement milestone such as rolling, crawling, pulling to standing and walking. As they integrate patterns and relationships, or as they learn a new movement there is a marked increase in brain activity which can present to parents as clingy, fussy and unpredictable.

While this can be frustrating and lead to less sleep for everyone, I assure you, your baby is doing exactly what she or he needs to be doing and it is a really good sign of important development.

During these periods, researchers and experts alike suggest various activities that can help with this stage in your child’s learning. The book Wonder Weeks or the app can offer some of these suggestions.

Survival tips for navigating the Wonder Weeks:

  • During the periods when a developmental leap is occurring, it is generally not a great time to start sleep changes as your little one will need extra support and connection and will likely resist sleep changes.
  • Do your best to offer more comfort, be patient and take deep breaths.
  • Maintain as much consistency with bedtime as possible and comfort at night when your baby wakes.

During this time your baby will be taking on so many new motor skills, increasing their perception, and integrating important information about the world around them…and it is a lot of work!

These periods during the Wonder Weeks can be frustrating and unpredictable therefore as parents it is crucial that we prioritize self care and practice patience so we can support our babies as they learn and navigate through their first year of life.

One practice that I have found in my work with parents that is really essential is levity and laughter.

With that in mind, please enjoy the following video on one of the joys of parenthood….laughter.

About the Author

Hi, I’m Sarah. As a mother of two, I quickly learned that sleep is influenced by a variety of factors and there is not one RIGHT way to help baby sleep. Both of my daughters had unique temperaments and struggles, and I was humbled to learn that newborns are complicated and parenting in a world of information overload is stressful. Now, I partner with parents to create a tailored plan using an evidence-based and multidimensional approach to sleep. I take great care in co-creating a plan that takes into account all of the factors that makes each family unique, including parenting philosophies, infant temperament and readiness, age, weight gain, health and development and much more. To date, I have helped over 2,000 families. If you’re ready to get your family’s sleep back on track, contact me.