top of page

The Science of Baby Sleep

There is an entire science behind the behavior of sleep! Sleep training is not just about the method you choose, but also about understanding what goes on in your child’s body during sleepy times and awake times.

Continue reading to learn more about the science of baby sleep.

NJ BEST sleep consultant

Circadian Rhythms

Once a baby is about 4 months old, their bodies will have sorted out their internal body clocks, or their circadian rhythms. Their bodies begin to tell them to stay awake for longer stretches when it is light out, through the release of cortisol, and go to sleep for longer stretches when it’s dark out, through the release of melatonin.


It is a neurotransmitter, or a chemical messenger, that affects the behavior of sleep. As the day goes on, adenosine slowly builds up in your body, causing you to become sleepier. This is also known as sleep pressure. In a baby, hitting the “sweet spot” between a rise in adenosine and the fall of the circadian rhythm allows them to fall asleep more easily.


Cortisol is known as our stress hormone, but it does more than help us “fight or flight!” Healthy levels of cortisol turn on systems in our body that not only help keep us awake, but also regulate energy levels, blood pressure and blood sugars, to name a few. When cortisol is too high (and you’ve missed that “sweet spot” for sleep), you may see signs of an overtired baby.


Melatonin is probably the most well-known sleep hormone. It is secreted in the body at the same time that your circadian rhythms tell you “it’s time to sleep!” Darkness (such as the nighttime sky or room darkening shades) induces the release of melatonin. This is why I always suggest using room darkening shades, especially during the day when your baby is napping.

During a consultation, I always explain the science of sleep and how it affects your child’s schedules and sleep hygiene.

This gives concrete, researchable, and tested solutions to sleep issues. I find relying on the science to prove more successful in sleep training than suggestions like wake times (after 4 months of age) and will always explain my reasoning behind my suggestions. Are you still struggling with your child’s sleep?

Check out my packages and pricing by clicking below.

Rest Well,


NJ BEST sleep consultant
11 views0 comments


bottom of page