Baby sleep regression: Everything you need to know

Baby sleep regression is a challenge that many families face in the first year of infancy. When a baby starts waking up in the middle of the night and refusing to go back to sleep for no apparent reason, parents often feel distressed. However, in most cases, there is no real cause for concern. What parents may not know is that during these difficult periods, babies go through important stages of cognitive and physiological development which may cause the disruption of their sleep habits. 

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What is baby sleep regression?

Sleep regressions in babies are periods of time when infants suddenly start to deviate from their sleep patterns. They usually last from a few days to a few weeks. Babies who had been consistently sleeping well start to (repeatedly) wake up at night, refuse to go down for a nap or wake up early from their naps. These changes in babies’ sleep are often unexpected and pose new challenges to parents who think they had already cracked the code to their baby’s sleep. 

The concept of infant sleep regression has been a topic of discussion in developmental psychology for decades. It first gained traction in 1992 when a peer-reviewed study published in the Journal of Reproductive and Infant Psychology found that human infants go through periods of disorganization/regression that occur at specific ages. The study conducted by Dutch psychologists Dr. Frans Plooij, Ph.D. and Dr. Hetty van de Rijt, Ph.D. suggested a possible link between periods of sleep regression in babies and cognitive developmental transitions. This theory would explain why baby sleep regressions happen in the first place. 

According to the authors, who summed up their findings in the bestselling book titled The Wonder Weeks, the sudden changes in infant behavior when babies seem to regress to a younger age are intrinsically linked to developmental milestones as the baby’s brain grows and they start to develop new skills. 

It’s important to note that Dr. Plooij and Dr. van de Rijt’s study was conducted among a relatively small pool of participants – 15 mothers and their babies. While the sample of this particular study may not have been substantial and large-scale research has yet to confirm its findings, independent research groups have succeeded at replicating them. Today, the concept of baby sleep regression is widely accepted among psychologists. 

Baby sleep regression by ages

There is no general consensus around when this occurs. But supporters of the idea that leaps in cognitive development are accompanied by periods of regressions usually point to the following four periods. 

Baby sleep regression at 4 months

The first sleep regression is commonly experienced at 4 months. This initial change to the baby’s sleep patterns can be especially hard on unsuspecting parents. However, it’s important to keep in mind that sleep regressions are likely to be signs of progress. 

At 4 months, the brains of infants go through rapid growth spurts as they acquire a variety of new skills and capabilities. This is when babies start learning how to raise and hold their heads up, roll over or sit upright on their own. Some babies already start being able to distinguish language from other sounds. What’s more, at 4 months, infants’ sleep cycles are maturing and they are starting to spend more time in a less deep (non-REM) sleep stage. These factors are all likely to contribute to more frequent awakenings during the night and issues with napping during the day.

Baby sleep regression at 6 months

The next period of intense brain development in infants starts at 6 months. During this time, there’s an increase in the frontal cortex’s consumption of glucose which coincides with changes in cognitive behaviors, as shown in the study “Biological Basis of Emotions: Brain Systems and Brain Development“, of “Pediatrics” (1*). 

6 months is also when infants’ circadian rhythms start to resemble those of adults. According to research (2*), by 6 months the proportion of active sleep (an immature form of REM sleep) diminishes to about 25% of sleep time. At this age, babies start to enter sleep through a non-REM stage and muscle tone inhibition starts to occur in REM sleep. These changes in the sleep cycle may cause temporary sleep disruptions. 

Additionally, a change in diet (the 6-month mark is often when parents start their babies on solids) and discomfort related to teething can also impact an infant’s sleep habits. 

Baby sleep regression at 8 months

Starting from 8 months, babies go through another stage of rapid development which can affect their sleep patterns. For example, this is when they start learning how to pull themselves up into a standing position. A study found that early-achievers who hit the developmental milestone of pulling-to-stand at 8 months experienced disrupted sleep. 

8 months is the age when most babies start to crawl. Their communication skills are also rapidly developing, causing their minds to be constantly occupied – and potentially messing with their sleep. 

Baby sleep regression at 10 months

By the 10-month mark, most babies can stand on their own and are about to take their first steps. This is yet another huge developmental milestone that may contribute to sleep issues. 

Another occurrence that may be keeping toddlers up is their new-found fascination with social interaction and communication. 

In some cases, can happen as late as 18 to 24 months. However, evidence on toddler sleep regression is scarce. 

What are the signs of baby sleep regression

Not every baby shows clear-cut signs of sleep regression at exactly 4, 6, 8 and 10 months. But there are some behaviors that may indicate a baby is going through a regressive phase. 

• A sudden change in sleep patterns (frequent nighttime wakings and less daytime napping)
• Fighting sleep
• Fussiness
• Changes in appetite 

Fortunately, these periods only last for a few weeks. Then, the baby’s sleep patterns consolidate again until the next period of regression. 

How to manage baby sleep regression

Sleep regressions affect babies and families to varying extents. Some parents find them very tasking and difficult to deal with. The good news is, there are measures that parents can take in order to lessen the impact of this disorder. 

1. Stick to a routine

When it comes to managing sleep regression in babies, there’s nothing more effective than sticking to an established routine. A well-planned bedtime routine should include a chain of activities that can be performed consistently every single night: taking a bath, changing into pajamas, dimming the lights, reading a story, singing a lullaby, etc. The emphasis is on consistency: it doesn’t matter what the nighttime routine involves as long as you are consistent with it. This will help your baby switch to night mode and fall asleep more easily. 

2. Offer extra comfort

When dealing with sleep regressions, parents should offer extra comfort and attention to babies who may need it during these difficult times. However, you should avoid creating sleep associations that you won’t be able to maintain in the long run, like nursing or rocking your baby to sleep. You should try to put your baby down when they’re drowsy but not quite asleep yet, so they learn how to fall asleep independently. 

3. Adjust bedtime

Going through a period where your baby wakes up at night often means hours of fussing and crying during the night. To make sure your baby doesn’t get overtired and that their mood during the day isn’t affected by their lack of sleep during the night, adjust their bedtime and get them ready for sleep a bit earlier than usual. This will give you a chance to get some more rest, too. 

4. Create the right environment

Silence and darkness are a parent’s best allies when it comes to managing infant sleep regression. Create an ideal environment for peaceful, undisturbed sleep by darkening the nursery and protect your baby’s slumber from noises that might keep them awake. 

5. Keep nighttime feedings short

Sudden growth spurts in infants are often accompanied by an increase in appetite. Parents should listen to their baby’s hunger signals and incorporate extra feedings into their routine if necessary. However, you should aim to keep nighttime feedings short and quiet. Babies need to learn that nighttime is for sleeping. Avoid turning on lights and electronic devices and make sure you don’t start playing or moving around as much as you would during the day. 

Conclusion about babies sleep regression

Baby sleep regression is an unexpected challenge that can leave many parents feeling perplexed. However, it’s a natural part of an infant’s development and most likely signals that the baby is going through rapid cognitive and physiological growth. 

These periods of wakefulness can be managed by establishing a bedtime routine that parents can stick to, offering extra comfort to babies when needed, adjusting bedtime, creating the ideal environment for sleeping and keeping nighttime feedings short and quiet. After a few weeks of disrupted sleep, babies can be expected to start sleeping well again.

Sources:
– (1*) https://pediatrics.aappublications.org/content/102/Supplement_E1/1225
– (2*): https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1021.9137&rep=rep1&type=pdf