Let the light in!

By Angela Wilson
Certified child sleep consultant, MA Natural Sciences Cambridge University and co-founder of Baby Smiles Club 

There’s one REALLY simple thing you can do to help your baby sleep well at night. And that’s to let in the daylight at morning wake-up! Open the curtains or the blinds, and let the light flood in :) 

Why? Because sunlight sends a signal to your baby’s brain that it’s time to be AWAKE. The light activates one of the two hormones responsible for sleep in your baby – cortisol. It’s known as the ‘stress hormone’, but it’s what makes you feel alert and awake, giving you the energy to get through the day. 

Now, cortisol works in tandem with melatonin, which is the other hormone responsible for your baby’s sleep. Melatonin is known as the ‘sleep hormone’, and it’s what makes you fall and then stay ASLEEP. It’s triggered by nightfall and remains in your system throughout the night.  

When things are in sync 

When your baby’s sleep hormones are in sync, they’ll sleep better at night and feel more awake in the day. That’s good news for your baby and for you! 

When things are working as they should be, your baby’s melatonin production is high at nighttime (making it easier for them to fall asleep and to go back to sleep after a night feed), and cortisol production is high in the daytime (making your baby have energy in the day). The hormones should rise and fall like this: 


When things go out of sync

Unfortunately, it’s easy for things to go wrong. What can happen? 

  1. Your baby should start producing melatonin at around 6:30pm–7:30pm. But this can be hampered by artificial light. So if you’re sat with bright lights on or watching the television whilst feeding your baby before bed, this really isn't helping. 

  2. Your baby’s cortisol levels can be impacted by becoming overtired. When a baby becomes overtired, their stress response system kicks in and cortisol is released. A baby being overtired at bedtime is like you having an espresso right before bed! 

We explain all about sleep hormones in our Baby Sleep Program. And we’ve created age-specific routines that suggest sleeping (and feeding) times for your baby to get the best sleep that they can. Our Program has two foundations: the most up-to-date science about how babies sleep, and strengthening the parent-child bond. 

Find out more about our Baby Sleep Program