Ever wonder what is happening when your little one acts fussy one day, making for a really hard day or two of regular activity or sleep? Some can confuse this with a growth spurt but it’s actually called The Wonder Week. A Wonder Week is similar to a growth spurt but instead of the body, it its specifically only to the brain. The changes that are going on in their brain are important changes that advance a child’s physical and mental skills. But it gives a child an entire new perception of their world. As you can imagine, it creates a confusing and stressful feeling for a child. This then becomes the reason for a very fussy baby during a short period of time.

When are these Wonder Weeks?
There are ten Wonder Weeks in the first 20 months of a baby’s life and can last anywhere from three days to a few weeks. Knowing when they occur can help you understand your baby’s sensitive and fussy state. When you calculate the week, do so by starting from the due date, not the actually delivery date. I have included the months for you below with each of the weeks. There are also charts and apps you can use that can help you see if your child is going through a Wonder Week. You can also purchase the book here, where you’ll be able to get some fantastic tips on how to help baby reach his potential during and after these weeks.

• Wonder Week 5 – fussiness starts around 5 weeks and usually lasts 1-7 days.
• Wonder Week 8 – fussiness starts around 8 weeks and usually lasts 3-14 days
• Wonder Week 12 – fussiness starts around 12 weeks/2.8 months and usually lasts 1-7 days
• Wonder Week 19 – fussiness starts around 15 weeks/3.5 months, peaks at 17 weeks and skills appear around 19 weeks. It usually lasts 1-6 weeks **From now on Fussy periods will last longer than previously
• Wonder Week 26 – fussiness starts around 23 weeks/5.3 months, peaks at 26 weeks and skills appear around 26 weeks. It usually lasts 1-5 weeks
• Weeks 29/30 or 6.8 months – This isn’t actually a Wonder Week, but many babies act fussy during this time as they begin to understand that their mommy can leave them.
• Wonder Week 37 – fussiness starts around 34 weeks/7.8 months, peaks at 36 weeks and skills appear around 37 weeks. It usually lasts 3-6 weeks
• Wonder Week 46 – fussiness starts around 42 weeks/9.7 months, peaks at 44 weeks and skills appear around 46 weeks. It usually lasts 3-7 weeks
• Wonder Week 55 – fussiness starts around 51 weeks/11.7 months, often peaks at 53 weeks and skills appear around 55 weeks. It usually lasts 3-6 weeks
• Wonder Week 64 / 14.7 months
• Wonder Week 75 / 17.2 months
• Over 20 months – Other wonder weeks have been documented throughout childhood. It is also suspected that adults even go through some wonder weeks.