We have an internal clock, also known as the Circadian Rhythm, which helps us feel awake during the day and sleepy at night time. Serotonin, the awake hormone, is produced during the day and Melatonin, the sleep hormone, is produced at night time, setting us up for sleep.
The Melatonin Hormone
Maternal melatonin allows babies to fall asleep anywhere quite easily, until around 3 weeks old, as the melatonin that comes from the placenta is quite high. This melatonin slowly decreases until they start producing their own melatonin, around 8 weeks old. Did you notice that when your baby hit that 8 week mark, that they started catnapping, were more alert and harder to get to sleep on the go? That’s because the high amount of maternal melatonin has now disappeared and they are now producing their own melatonin.
The Serotonin Hormone
Now it’s time to shed some light on Serotonin, the awake and happy hormone. Serotonin is actually converted into melatonin and supports sleep. Serotonin is produced from light and signals to the brain that it is time to wake up. The aim is to have a good balance of both melatonin and serotonin hormones, as they work together to allow your child to sleep well.
How can you help your child produce serotonin? You can open the blinds during the day to let in natural light, safe exposure to sunlight each day, you can go for a walk in the pram, have morning or afternoon tea on the lawn in the backyard or go for a walk and play in the park.
What affects the sleep hormones?
Any light from the sun or artificial light from lamps, technology etc affects the readiness for sleep, as light produces serotonin and blocks melatonin production. Have you noticed that your child does not sleep as well or is difficult to settle to sleep in a light environment? When your child is in a dark room, melatonin is produced by the Pineal Gland, which makes it much easier for your child to fall asleep, stay asleep, learn to link sleep cycles and have consolidated and restorative sleep.
I don’t recommend any night lights until over the age of 2 years old, when some toddlers may have a genuine fear of the dark. If your toddler develops a fear of the dark and you need to provide a night light, I recommend a red light that is as dim as possible and in the corner of the room out of direct sight. I recommend the room being as dark as possible for all naps, overnight and especially when the sun rises.
When it’s time for your child to have a nap, you want their room to be as dark as possible, as this allows serotonin to be converted to melatonin, which will help your little one get ready for sleep, fall asleep and stay asleep.
Rachel Thompson is a certified Baby Sleep Consultant based in Australia but offering her services worldwide.
Why Rachel wants to help parents and babies with their sleep problems:
My journey of becoming a new mumis by far the best life experience and is incredibly rewarding, but it can also be a rollercoaster with many challenges, running emotions and sleep deprivation just adds to it...I myself have experienced the depths of sleep deprivation and I know the impact it can have on all aspects of your life. I wanted to help ourson develop healthy sleep habits while he was young, and well into the future as he grows.My sleep deprivation actuallyinspired me to want to become an Infant and Child Sleep Consultant, because I love science, so learning all about sleep was fascinating.I am passionate about helping other families around the world get quality sleep and learn the invaluable skill of sleep.
Find out more about the services Rachel offers on her websiteRockabye Baby Sleep Solutions, and follow her for great tips and advice on Instagram.
FAQs
The Melatonin Hormone
How does cortisol affect baby sleep? ›
Optimal sleep behaviors in infancy relate to higher cognitive development in toddlerhood. Optimal sleep behaviors in infancy relate to higher language development in toddlerhood. Toddlers' higher morning cortisol levels are linked to better sleep.
Does mother's sleep affect baby sleep? ›
This study found that postpartum sleep disorders of mothers could directly increase the risk of infant sleep disorders. In addition, maternal sleep disorders occurring extend from the third trimester of pregnancy to the postnatal period impact infant sleep seriously.
Is the 4 month sleep regression a myth? ›
Is the 4 month sleep regression real? Yes! Some babies may not show signs of the 4 month sleep regression, which is why some people wonder if the 4 month sleep regression is a myth. However, the shift in sleep patterns that takes place around 3-5 months is a real biological change that all babies go through.
How does sleep affect baby's development? ›
Infant sleep plays an important role in a child's development, including cognition and physical growth – it's associated with overall cognitive development, as well as specific cognitive functions such as memory, language and executive function.
How to lower cortisol in a baby? ›
Stress can take many forms but there are some serious signs we should be aware of in babies that can definitely negatively impact their sleep. Studies have shown that dealing with your baby in gentle ways—cuddling, caressing, sweet talk, etc—can all help lower cortisol levels and thus lower stress in babies.
What happens to babies with high cortisol levels? ›
Cortisol helps your child's body respond to an illness or injury. It also stabilizes blood pressure and blood sugar levels. When the body produces too much cortisol, it can slow a child's growth, disrupt puberty, and cause obesity, mood changes, and a variety of other symptoms. Cushing's syndrome is extremely rare.
Why do babies sleep better in moms bed? ›
If you've found that your baby sleeps better in your bed, there are several reasons for that. Here are the most common: Your baby feels safer and more secure, making it easier to fall asleep. Your baby recognizes your face, voice, and touch more easily.
Why does baby sleep longer with mom? ›
At the same time, both adults and babies sleep longer overall when they bedshare, probably because caregivers don't have to get all the way up out of bed to feed and babies don't have to call out, wait for help, and settle back down. And that longer sleep has implications for parent-child interactions in the daytime.
Why does baby fight sleep with mom? ›
Babies fight sleep for a variety of reasons the seven most common being separation anxiety, overtiredness, overstimulation, teething, hitting a milestone, traveling and discomfort or illness.
Some babies may start sleeping from 7pm to 7am as early as 3 months, while others may not reach this milestone until they are closer to a year old. It's important to remember that every baby is different, and there is no one-size-fits-all sleep schedule.
Why are some babies good sleepers? ›
Babies with self-soothing sleep temperaments are more easily able to drift off to sleep when bedtime begins, as well as get back to sleep on their own when they wake. These self-soothing sleepy-heads may also snooze for longer periods of time, or start sleeping through the night sooner than other babies.
When do babies sleep 12 hours without feeding? ›
Most babies are developmentally capable of sleeping through the night by around 5 months (though some may still need a night feeding until they're closer to 8 or 9 months). If you need help with sleep strategies and you're not sure where to begin, I can help!
Will lack of sleep affect fetus development? ›
Corticosterone levels were comparable between the two groups, although ACTH levels were elevated significantly in the sleep deprivation group. Our study revealed that sleep deprivation during pregnancy can adversely impact fetal outcomes.
What is the most common infant sleep-related problem? ›
According to parents and child-care professionals, bedtime, or night waking problems are the most common infant sleep problems (8, 10, 12–14).
How does cortisol affect newborns? ›
Stress in pregnant mothers – measured through levels of the stress hormone, cortisol – have been linked to changes in infant brain development of the amygdalla, which is involved in children's social and emotional development.
Does high cortisol cause sleep problems? ›
How does cortisol affect sleep? High cortisol levels have been linked to insomnia, waking up during the night, and less sleep time overall. When cortisol levels are normal, the hormone helps you wake up in the morning (when levels are higher) and drift off at night (when levels are lower).
When does cortisol peak in babies? ›
On a daily basis, the HPA axis produces peak levels of cortisol in the morning during the final phases of sleep and minimum levels of cortisol at night during the early phase of night- time sleep (Born & Fehm, 1998).
How does cortisol affect child development? ›
Children who grow up in stressful environments often have elevated levels of "the stress hormone” cortisol, which can impair cognitive development. New research shows that some children growing up with adversity actually have low levels of cortisol, which is also linked to compromised cognitive functioning.
