What is a circadian rhythm?
If there is one piece of advice that we are given as new parents that is to ‘sleep when your baby sleeps’. In an ideal world this advice is great, but what happens when your baby doesn’t want to sleep, let alone your baby doesn’t want to sleep anywhere but on you. Newborns don’t have a predictable routine. This is because their internal body clock known as the circadian rhythm has not developed yet. This 24-hour cycle that drives our wakefulness and sleep periods develops around 6-12 weeks.
In utero, the circadian rhythm is linked to maternal hormones. Once they are born and reach around 6-12 weeks, they start to produce their own melatonin, which is why you may start to see your baby sleep less and cat nap more.
First, let’s talk about why the circadian rhythm is so vital to our baby’s sleep.
WHAT IS THE CIRCADIAN RHYTHM?
is a 24-hour cycle that drives our wakefulness and sleep periods. It is controlled by temperature and the hormones cortisol, which wakes you and melatonin, which makes you sleepy. Cortisol and melatonin are largely influenced by external environments such as light (day) and dark (night). When our eyes see darkness, it sends a message to our brain to release melatonin.
HOW CAN YOU HELP TO KICK START THE CIRCADIAN RHYTHM?
As newborns don’t have this engrained in them until around that 6-12-week mark there are things we can do to help them ease into it.
Start watching their tired signs from birth and putting them to bed when they are showing tired signs.
Providing white noise from birth. This is a familiar noise to them so it’s no wonder that it’s totally relaxing. It distracts them from external disturbances and turns on the calming reflex.
Aim to have at least one motionless sleep a day
Black out their room from 6 weeks of age to increase the release of melatonin.
Turning off any night lights or glow lights in the room as this can be very distracting for babies. It is not advised to introduce this until around 3 when children develop fear of the dark.
Nap windows aren’t established in the newborn stage but working towards this will help with the development when it begins around 4 months. These windows are 9-10am and 12-2pm, then 6-7pm. This explains why it is so difficult to get a baby to sleep in the late afternoon as there is very little amount of melatonin present. There is a massive rise of melatonin and drop in cortisol at around 6-7pm, which increases the pressure to sleep at night. Based on this physiology, it is simple to see why it is important to create a structured routine around these times.