4-Month Sleep Regression in Babies: Facts, Tips, and Tricks

A sleep regression is a period when sleep gets more chaotic. Babies may resist their naps, wake more during the night, or struggle with sleep in general. 

But you know what? According to sleep researchers, these regressions do not exist. At least not how they are typically described. Many babies have periods when they sleep worse but there is not one single month when there is a peak in these problems. Not even at 4 months. Sleep regressions can happen to babies at different times. Or not at all. 

Finding it hard to believe me because you have been hearing about sleep regressions forever? Stick with me. 

Sleep regressions are not real because sleep is not a milestone that babies achieve at a specific age. Sleep researchers examine sleep development by examining markers such as how long the baby can stay asleep, and the percentage of REM sleep versus non-REM sleep. These markers develop rapidly during the first six months of a baby’s life. When a baby goes through a so-called sleep ‘regression’ those markers do not regress. Sleep may be disrupted but nothing is regressing. 

You may have heard that babies experience sleep regressions at 4 months, 6 months, 8 months, 12 months, 18 months and 24 months. The four-month sleep regression is the most infamous. But it is simply not real. 

Let’s Focus on the 4-Month-Old Sleep Regression: Why Do Some Babies Experience Worse Sleep Around This Age? 

At this time, babies tend to go through changes in their sleep architecture, but these changes can happen anytime between the age of three and six months.  

Sleep patterns are likely to change anytime between three and six months because it is when babies’ circadian rhythm⁽¹⁾ begins to mature, which causes their sleep cycles to change. Babies start to fully wake up while between these cycles and may need assistance falling back asleep. This often leads to more waking up at night and shorter naps. 

If this is happening to your baby, it probably means that your baby is moving out of their newborn sleep cycle and starting to develop their own unique cycle. Think of it as a progression rather than as a regression. In any case, sleep ‘regression’ does not mean that anything is going backwards. 

My Baby is Sleeping Worse than Before. Why? 

These ‘regressions’ happen not because of sleep per se, but because of many factors that are happening in your baby’s life.  These are some of the factors ⁽²⁾ that could explain why your baby is waking up more often:

• Learning a new skill: how to crawl, walk, roll over… All these changes may influence their sleep because they cause them to be overtired or too excited to sleep. It is not great for you, but for your baby is totally OK. What seems like a regression is a natural part of your baby’s development.

• Becoming more aware of their surroundings which may cause them to be overstimulated. 

• A growth spurt. 

• Separation anxiety.

• Teething.

• Hunger.

• Being sick.

• Medical issues, such as reflux. If you are worried, always talk to your doctor. 

What Can I Do?

The most important thing is to maintain good sleep hygiene for your baby, so they develop healthy sleep habits from a young age. 

• During the day, the baby should not sleep in the dark and the level of noise should be the ‘normal’ at your household. 

• During the night, keep stimulation to a minimum. Try to limit household noise at bedtime. If you live in a noisy environment keep the windows closed and consider using noise-blocking curtains. 

• Have a bedtime routine to mark the difference between day and night. This routine should be the same every day. An effective routine could look like: Having a bath, perhaps with some soothing scents like lavender or chamomile, followed by a massage. The bath warms up the body so that the blood vessels near the surface of the skin dilate to help the body cool down, and this cooling helps your baby to feel sleepy. After the bath, change your baby into a clean nappy and pyjamas, feed him, and sing a lullaby or read them a story. Try to put them in their cot when they are drowsy but still awake, kiss them and say goodnight, allowing them to fall asleep on their own. Make sure the bedroom is cool, dark, and quiet. Between 16 and 20 degrees Celsius is ideal, and too cool is better than too hot. Everyone has a slightly different temperature preference so you may need to make adjustments to find your baby’s ideal temperature. Feeling your baby’s chest or back when they are asleep should give you a good indication. They should feel warm but not clammy. 

• Be flexible. Your baby’s needs are changing and therefore you may need to adjust the number or length of their naps, or their bedtime. 

Remember: If your baby’s sleep is changing, it is not regressing but progressing! 

If Research Finds No Evidence of Regressions, Why Do So Many Experts Talk About Them?

The sleep field is unregulated. This means that anyone can call themselves a sleep expert, a sleep coach, a sleep consultant (you name it!), and start advising families. Sleep coaches in countries like the UK, range from experienced ex-NHS staff and qualified psychologists to nannies or child-minders who have completed a two-day course. 

Many of these professionals are well informed and they genuinely want to help families. But others are not. And they create problems such as regressions to then tell families that they know how to fix them and that they should hire them. 

There is nothing wrong with hiring a sleep consultant if you want help. However, beware of who you hire. Before you hire anyone, check their credentials, ask about their ethical guidelines, ask to see previous clients’ opinions, and make sure their working style match with your needs and beliefs. For example, do not hire anyone who will let your baby cry if you do not want any crying. Remember that sleep training is not recommended until the baby is at least 6 months old. 

Sleep Regressions Are Misunderstood. Remember That There Are a Lot of Misconceptions About Baby Sleep.

It is often said that information is power. This is especially true in the case of sleep. Here are some common misconceptions ⁽³⁾ or false beliefs about baby sleep:

1. The best bedtime for babies is 7 pm: You may have been told that babies must sleep from 7 pm to 7 am. This is considered the golden standard by many parents and professionals. The reality is that there is no research showing that this is best for babies. Moreover, bedtime for babies is very much influenced by culture ⁽⁴⁾ . In the UK, it is very typical for babies and children to go to bed at 7 pm whereas for example, in many Mediterranean countries, babies and children go to sleep much later.

 2. All babies must sleep 12 hours: This is not the case. Some babies need 12 hours whereas others do not need as much sleep. In general, if your baby is happy, healthy, does not look tired, and their hours of sleep fall within the recommended hours, it is unlikely that they are not getting enough sleep. 

3. All babies must be sleep trained: Not at all! There are many babies that are not sleep trained and that learn to sleep fine. There is no right way to get your baby to sleep. Do whatever works for your family. Some families choose to co-sleep, others choose to keep the baby in another room and go to them whenever they cry, and others choose to sleep train. There is no right or wrong answer. The most important thing when considering baby sleep is safety. As parents it’s crucial that we are aware of the guidelines to reduce the risk of accidents and of SIDS. Learn more about baby sleep safety here.

4. Babies must be taught to sleep: Babies do not need to learn how to sleep. When they are born, they are fully capable of sleeping because they have been sleeping in utero for the last few months. 

If you want to learn more about baby sleep, we have four REC Parenting masterclasses you may find useful: 

• What is Normal Sleep for a Baby? with Professor Helen Ball

• Sleep Safety for Babies with Professor Helen Ball

• Sleep Hygiene for Children and Adolescents with Dr Anna Joyce

• Baby Sleep: What to Do When Things Don’t Go as Planned with Dr Ayten Bilgin 

• Baby Massage with Lucy Johns 

Join REC Parenting today to get access to these masterclasses! 

If you are considering hiring a sleep consultant, get in touch so we can recommend the one that will suit best your family’s needs. 

If you have any specific questions on baby sleep, drop them here and I will answer it in the REC Parenting weekly Q&A email. 

I hope you have found this information useful.

Ana

Dr Ana Aznar

References

(1) Joseph, D., Chong, N. W., Shanks, M. E., Rosato, E., Taub, N. A., Petersen, S. A., … & Wailoo, M. (2015). Getting rhythm: how do babies do it?. Archives of Disease in Childhood-Fetal and Neonatal Edition, 100(1), F50-F54. https://doi.org/10.1136/archdischild-2014-306104

(2) Reuter, A., Silfverdal, S. A., Lindblom, K., & Hjern, A. (2020). A systematic review of prevention and treatment of infant behavioural sleep problems. Acta Paediatrica, 109(9), 1717-1732. https://doi.org/10.1111/apa.15182

(3) Schreck, K. A., & Richdale, A. L. (2011). Knowledge of childhood sleep: a possible variable in under or misdiagnosis of childhood sleep problems. Journal of sleep research, 20(4), 589-597.https://doi.org/10.1111/j.1365-2869.2011.00922.x

(4) Mindell, J. A., Sadeh, A., Kohyama, J., & How, T. H. (2010). Parental behaviors and sleep outcomes in infants and toddlers: a cross-cultural comparison. Sleep medicine, 11(4), 393-399.https://doi.org/10.1016/j.sleep.2009.11.011