Understanding and Navigating the Four-Month Sleep Regression
What is the Four Month Sleep Regression?
Around the four-month mark adjusted to the estimated due date, your baby's sleep patterns undergo a significant transformation. Previously, they may have been sleeping longer stretches at night, but suddenly you may find them waking up more frequently, taking shorter naps, and displaying less consistency in their sleep routine. While this regression may seem worrisome and disruptive, it is actually a positive sign of your baby's neurological development.
Signs and Symptoms of the Four-Month Sleep Regression
Several signs and symptoms may indicate that your baby is going through the four-month sleep regression. These may include:
1. More frequent night awakenings: Your baby may wake up more frequently during the night, requiring increased parental support to fall back asleep.
2. Difficulty settling: It might become increasingly challenging to soothe your baby to sleep, as they may resist their usual sleep routines or methods.
3. Shorter naps: Daytime naps may become shorter and more unpredictable, leading to overtiredness throughout the day.
4. Increased fussiness: Your baby may exhibit increased crankiness, irritability, or general fussiness due to disrupted sleep patterns.
What Causes the Four Month Sleep Regression?
A four month sleep regression can occur because babies are in the midst of a major transition away from a newborn sleep pattern. The process of forming and linking different areas of the brain and nervous system may create instability in their sleep transitions that are not always smooth; they may have plateaus or setbacks like sleep regressions (1). There is typically no single cause for a four month sleep regression, but some contributing factors may include:
An uneven transition into consolidated sleep
Disturbances in the infant’s sleep environment
A greater awareness of their surroundings, which can result in overstimulation
Separation Anxiety
Around four months, infants begin to sleep more like an adult. They drift off into a light sleep that guides them into a N-REM cycle (deep sleep). Then, they have a brief partial awakening that is followed by a REM cycle (light, active sleep). We all, even as adults, wake-up throughout the night during brief partial awakenings between sleep cycles. We typically go right back to sleep and do not remember waking.
However, young infants may fully wake up between sleep cycles. Often they fully wake because the methods that may have worked well for the newborn phase (feeding and rocking completely to sleep in our arms) may start to get in the way of connecting sleep cycles as they become more aware. When babies are placed into their bassinet fully asleep, they have their partial wake up between sleep cycles in a different environment. Their bodies expect their surroundings to be unchanged during these wake-ups; this results in the child fully waking throughout the night and after a brief 20-40 minute nap (the length of the N-REM cycle).
We can also unintentionally reinforce these wake-ups further by responding to each night waking with a feed. It’s easy to assume that our baby may be going through a growth spurt when it is actually a developmental change. When we feed our baby every night waking, babies may form a habit of waking very frequently for feedings. While, typically babies still need night feedings at four months, waking every hour or two for night feeds is no longer needed in typically developing children.
Do all Babies Have a Four Month Sleep Regression?
Not all babies have a 4-month sleep regression. Research has shown that there is a considerable amount of individual variation in infant sleep (2).
Many babies may have no detectable sleep regression at 4 months, while others may have difficulty sleeping at this age or a few weeks earlier or later.
How Long Does the Sleep Regression Last?
The sleep regression typically lasts a few weeks, but the effects of the transition can last longer. In my newborn package, you can learn how to gradually work on supporting babies to fall asleep independently without crying to sleep by using sleep timing and soothing routines. While it’s impossible to avoid the developmental changes that cause the four month sleep regression and even the best sleepers may experience some challenges during this time, there is a lot we can do to support sleep during this window and minimize the effects of this developmental shift.
Tips for Supporting the Four Month Sleep Regression
While the four-month sleep regression can be frustrating, implementing a few strategies can help navigate this challenging phase:
1. Create a consistent, sleep-friendly environment: Ensure your baby's sleep environment is quiet, dark, and cool (68-72 degrees) to promote restful sleep.
2. Practice an appropriate daytime schedule: Offer age-appropriate naps throughout the day to prevent overtiredness and encourage healthier sleep patterns. As your baby gets older, they will be able to stretch a little more between naps. Typically, wake windows will last between 90-120 minutes. Keep an eye out for the daytime biological sleep patterns that emerge around four months. The first nap will begin to fall between 8:30-9:00 am, second nap at 12:30-1:00 pm, and brief nap around 3:30 to bridge to bedtime around 5-6 months.
3. Have a consistent soothing routine - A predictable, calming routine helps babies know what to expect.
4. Provide a flexible, early bedtime - An early bedtime is the best way to get rid of built up sleep debt, and it is much easier to put down a child who is not already overtired. Aim for a bedtime between 6-8 pm.
5. Practice observation - Studies show that babies who have caregivers who understand and can read their cues sleep better (3). Check out my blog about sleepy cues.
6. Provide access to natural light - Natural light helps adjust your baby’s internal clock and promotes nighttime sleep (4).
7. Soothe your baby in their crib
8. Be responsive, but gradually reduce nighttime support -Respond to your baby's needs during the night, but gradually reduce the level of parental support to give them a chance to self settle and fall back to sleep.
9. Consider sleep associations - Review any sleep associations your baby may have developed and gradually wean them if they hinder sleep.
10. Feed them before bed while it is dark and quiet - Continue to offer feedings every few hours based on your baby’s hunger cues.
11. Consider using a transitional swaddle - Babies may begin to roll over independently around four months. This is a time to transition away from the swaddle. Using a transition swaddle such as the swaddle-me or the swaddle-up can help ease this transition.
12. Take care of yourself - Supporting our baby’s sleep can be very challenging and taxing. Get support from loved ones, take breaks, and do self care whenever possible. The more regulated and supported the caregiver is, the easier to help regulate and support their baby.
13. Seek support - Don't hesitate to reach out to a pediatric sleep consultant who can provide personalized guidance and support. Remember, every baby is unique, and the duration of the regression phase may vary. By practicing patience, implementing consistent strategies, and seeking assistance when needed, you can help your baby navigate the four-month sleep regression and restore peaceful nights for the whole family. Soon enough, both you and your little one will reestablish healthier sleep patterns and enjoy restful nights.
When Should Caregivers Talk With a Doctor About Sleep Problems in Four Month-Olds?
Talk to your doctor if you have concerns about your baby’s sleep or increased nighttime awakenings. It is important to consult with your pediatrician if you also notice:
Lack of growth or weight gain
Changes, especially reduction, in urination or bowel movements
Abnormal breathing during sleep
References
Blumberg, M. S., Gall, A. J., & Todd, W. D. (2014). The development of sleep-wake rhythms and the search for elemental circuits in the infant brain. Behavioral neuroscience, 128(3), 250–263.
https://pubmed.ncbi.nlm.nih.gov/24708298/
Mindell, J. A., Leichman, E. S., Composto, J., Lee, C., Bhullar, B., & Walters, R. M. (2016). Development of infant and toddler sleep patterns: real-world data from a mobile application. Journal of sleep research, 25(5), 508–516.
https://onlinelibrary.wiley.com/doi/10.1111/jsr.12414
Keys EM, Benzies KM, Kirk VG, Duffett-Leger L. Effect of Play2Sleep on mother-reported and father-reported infant sleep: a sequential explanatory mixed-methods study of a randomized controlled trial. J Clin Sleep Med. 2022 Feb 1;18(2):439-452. doi: 10.5664/jcsm.9618. PMID: 34409935; PMCID: PMC8805006.
Wood LA, Tomlinson MM, Pfeiffer JA, Walker KL, Keith RJ, Smith T, Yeager RA, Bhatnagar A, Kerstiens S, Gilkey D, Gao H, Srivastava S, Hart JL. Time spent outdoors and sleep normality: A preliminary investigation. Popul Med. 2021 Mar;3:7. doi: 10.18332/popmed/132119. Epub 2021 Mar 4. PMID: 34485920; PMCID: PMC8411876.
