Promoting Infant Circadian Rhythms


You may have heard the phrase “She has her days and nights mixed up” in reference to a baby who sleeps all day and is up most of the night. The reason for this “mix up” is that brand new infants have not developed what is called a circadian rhythm.

A circadian rhythm is essentially a 24 hour internal clock that gives us cues as to when we should sleep and when we should be alert. Many of these cues are influenced by our exposure to light and our hormones. It generally takes 2-5 months for an infant to develop a good 24-hour circadian rhythm.

As a human who needs sleep (that’s you!) it is a good goal to work towards naturally helping your baby cultivate a strong circadian rhythm. You see, it is usually not the amount that a baby sleeps that is the problem- it’s that they don’t want to sleep when you do!

Try the following to help your little one develop a good sleep-wake cycle and make progress in sleeping a little less during the day and a little more at night:

Be active during the day. Allow your baby to experience light, noise and activity during the day. A great way to do this is to wear your baby in a carrier and go about your usual schedule. Don’t be afraid to expose them to noise. Your baby will begin to associate activity with daytime and restfulness with nighttime.

Expose your baby to sunlight in the afternoon. In addition to being active, get outside with your baby as weather allows and expose them to natural sunlight in the afternoon. Not only will your baby get some much-needed Vitamin D, but this also helps in a huge way to set their circadian rhythm. Several studies have shown that babies who are exposed to sunlight during the day sleep better at night than babies who are not exposed to sunlight.

Keep your evening environment cool, dark and quiet. Just as activity during the day helps your baby learn that daytime is for wakefulness, keeping your environment dark and calm in the evening promotes sleepiness! As best you can, keep baby away from screens and other “blue lights” that inhibit the production of melatonin. Even consider doing away with the nightlight and only using a small light (such as your phone light) on an “as needed” basis for diaper changes and feedings. Use a soothing white noise machine to drown out any startling sounds and keep the temperature cool. While this helps on a biological level to promote circadian rhythm and melatonin production, it also helps in a behavioral way to make nighttime “boring” so that your baby is less tempted to party all night 😉

Breastfeed before bed. Towards the evening, a mother’s breast milk naturally contains higher levels of tryptophan. Tryptophan aids the body in producing melatonin. If you are breastfeeding all the time, this fluctuation of levels will naturally aid your baby.  If you are breastfeeding and supplementing with formula, consider making it a habit to nurse as your bedtime feeding session. And if you are formula feeding only, make sure your bedtime feeds are dark and quiet.

One of several reasons that I only recommend attempting to sleep coach a baby after 3 months of age is because this crucial piece of biology that helps them sleep through the night simply isn’t in place yet! If you work to promote these rhythms in your baby from early on, it is a huge advantage. When you make the decision to sleep coach, you will be armed with the help of natural hormones and a good sleep-wake cycle and set up for success to guide your baby to sleep for longer stretches at night!

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I’m Katelyn,
Award-winning pediatric sleep consultant, child development expert, and most importantly, wife and mom.
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