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Helping Your Newborn Develop Their Circadian Rhythm

At Birth

At Birth – Your baby has been in a suspended state while in the womb, so they have no notable Circadian Rhythm at birth. Instead, they eat, sleep, system repeat, eat, sleep system repeat. As a newborn, your baby can rack up 16 to 18 hours of sleep a day.

It’s interesting to note that at this age, the majority of their sleep (75%) is infact, REM sleep. “active sleep”  REM sleep can be characterized by fluttering eyes or eyelids, twitching lips, irregular breathing and body movements. Your baby can also spend some time in this sleep cycle, grunting, squirming and even brief crying; they can look deceptively ‘awake’. However, movement and vocalization is entirely normal during this phase of sleep and it is during this sleep cycle that your newborn can wake easily from. With more parents using video monitors, it is fair to say that parents may well be attending to their babies prematurely, assuming that they are awake and disturbing them out of their sleep cycles, so it’s fair to say that parents over attentiveness can be causing more frequent wakes. During the REM sleep cycle, we as adults experience sleep paralysis, but this isn’t the case for babies as they usually retain the muscle tone and use it a lot during their sleep.

Our adult sleep cycles are governed by the psychological change that follows a 24-hour cycle, and exposure to light controls many of these changes.  Even if you are sleep-deprived, exposure to morning light helps us feel more alert during the day. Conversely, the absence of light in the evening signals to your brain to start producing melatonin, a hormone that triggers relaxation and makes you feel sleepy, helping you wind down and fall asleep more easily.  A strong circadian rhythm does not yet govern newborn sleep. When babies are still in the womb, their physiological cues about day and night are more in tune with their mother’s physiological cues. Fetal heart and respiratory rates speed up when a mother is active. They slow down when a mother is sleeping (Mirmiran et al 2003). Maternal hormones, particularly melatonin, influence these changes. Maternal melatonin passes through the placenta and may direct the fetus’ internal clock (Torres-Farfan et al 2006).

Once a baby is born, they must develop their own hormonal production and circadian rhythms; studies have shown that newborns start o develop this rhythm from just a few days after birth, but this process takes time, and it can take up to 12 weeks for your baby to develop into day-night rhythms and produce their own melatonin.

As a parent, you can help this development along by implementing a Daily Routine.

Routines can help set and regulate your baby’s body clock into a 4-hour rhythm.

Implementing a strong bath and bedtime routine and reduce stimulation and light in the evening can help develop their night rhythm. A bedtime routine that is calm consistent with reduced lighting can help trigger sleep. Evening breast milk also contains tryptophan, an amino acid that is used by the body to manufacture melatonin. Tryptophan levels rise and fall according to maternal circadian rhythms, and when infants consume tryptophan before bedtime, they fall asleep faster (Steinberg et al 1992). If you feed your baby formula, try to find one that includes DHA. DHA is a fatty acid found in fish oil. DHA is important for brain development and may assist in developing sleep patterns as well.

In one study, children who consumed low levels of DHA had a reduced amount of slow-wave (deep) sleep (Faglioli et al 1989). In another study, pregnant women with higher blood levels of DHA gave birth to babies who spent more time in quiet sleep (Cheruku et al 2002).

When feeding overnight, keep stimulation to a minimum. Feed, quickly change your baby’s nappy and place them back into their cot to continue sleeping, keeping the light in the room and stimulation low. Once you place your baby back into the cot after an overnight feed, they may spend some time in REM sleep cycle (grunting, squirming etc)  this is entirely normal and doesn’t mean that they need your assistance.

Newborns need to feed frequently both during the day and overnight. However, some babies can start stretching out night feeds up to six hours within a couple of weeks most babies need to feed every three to four hours gradually increasing their initial block of sleep in the evening as they get older. So long as your baby is feeding well during the day, has lots of wet nappies and gaining weight consistently, there is no need to wake your baby for feeds overnight. If you are concerned about the length of time your baby is sleeping overnight, you should consult with your GP.

During the day and there awake times it is essential to expose your baby to as much natural and bright light as possible, research suggests that newborns sleep longer stretches at night when their parents expose them to more natural light during the day.

As with nighttime breast milk containing more melatonin, morning breast milk contains up to 3 times more cortisol than evening milk, this hormone stimulates alertness and also aids the development of the 24-hour circadian rhythm. For this reason, you will find it beneficial to label your expressed milk AM or PM when storing so you can choose the right one at the right time to offer your baby when needed. If you need to provide your baby with some express breast milk, try to offer them the appropriate milk a the appropriate time. If you need to provide them with EBM pumped in the morning, I encourage you to mix it with some of your PM pumped milk. Babies need to feed often and frequently. Encouraging your baby to feed more frequently during the day will reduce feeds overnight. Try to encourage your baby to feed every two to three hours during the day in the first few weeks. Gradually extending this out to three to four hours between two to four months will ensure that your baby is meeting most of the calorie needs during the daytime hours and therefore needing to feed less overnight time

All daytime feeds should be done in natural light, and you should encourage your baby to have short amounts of awake time during the day, thus implement the feed play sleep cycle. In the first few weeks, daytime naps can be in natural light and general day to day activity thus helping build the 24- hour cycle, but by six weeks I encourage all parents to start daytime naps in the same environment as the evening sleeps.

By 12 weeks of age, most babies will have developed some form of a 24-hour circadian rhythm although still very immature, and it is at this point, babies can start to become more aware of behaviours around their day-to-day flow and around their eating and sleeping. For this reason, I encourage parents to start helping their baby learn how to self soothe so they don’t become dependent on external factors later on. Helping, encouraging and supporting your baby in becoming an independent sleeper is a normal part of parenting and early childhood development. However, in an age of TMI and confusion about how you can help your baby sleep develop independently, parents are more confused than ever. The Lullababy SOS programe is designed to help parents understand the science behind sleep and how they can help encourage their baby to become independent sleepers and support them through this process.


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