Parents know extremely well that change comes fast for babies. They grow and develop at a rapid pace, and that includes shifts in their sleep pattern as they get older.
Newborns start out sleeping only in short segments, but over a few months a new trend develops toward sleeping for longer periods and spending more time sleeping at night.
Much to the dismay of many parents, this progression to a more stable sleep schedule can happen in fits and starts. Sleep patterns may change rapidly and even at times seem to go in reverse. This is often called a sleep regression, and it can occur at various points in childhood development.
The timing and nature of sleep regressions can vary for every baby, but it’s not uncommon for one to occur at around four months. Knowing the causes, signs, and ways to cope with a four-month sleep regression can help parents develop healthy sleep habits and support their child’s sleep.
This starts to change at around three months when a baby’s sleep starts to consolidate, meaning that they start to sleep for longer periods at a time. While multiple naps are still the norm, they may have longer nighttime sleep sessions and sleep fewer total hours (closer to 14-15 hours per day).
The process of sleep consolidation, though, is highly variable. At this age, the brain and body are developing rapidly, and the process of forming and linking different areas of the brain and nervous system may create instability in sleep. Babies are learning to react more and more to their environment, including adjusting to daylight, feeding, and other aspects of their day-to-day schedule.
A four-month sleep regression can occur because babies are in the midst of a major transition away from a newborn sleep pattern. That transition is not always smooth; it may have plateaus or setbacks like sleep regressions. The sleep instability that accompanies brain development at this age may be further affected by environment, physical growth, and sleep habits.
There is much that remains unknown about the underlying biology of sleep, so even pediatric sleep experts may not be able to point to one single cause for a four-month sleep regression.
Not all babies have a four-month sleep regression. Research studies have shown that there is a considerable amount of individual variation in infant sleep. Some babies may have no detectable sleep regression at four months while others may have difficulty sleeping at this age or at a somewhat earlier or later point.
At about four months, some babies show signs of worsening sleep. Examples of symptoms of a sleep regression include:
It’s natural for parents to wonder how long these symptoms of a sleep regression will last. In most cases, sleep problems only last for a few days to a few weeks, but this may depend in part on fostering good sleep habits that promote better infant sleep.
There’s no single solution to a four-month sleep regression; instead, parents are encouraged to cultivate healthy sleep routines and habits for their baby. Various tips often can not only help in the short-term but also create a framework for healthier sleep as your baby grows.
Another way to promote infant sleep is by creating a standard routine before bedtime. This can build cues for your baby that it’s time for sleep and has been found to make it easier for babies to fall asleep and stay asleep. This routine should include:
If your infant wakes up in the night, keep the following tips in mind:
If your baby cries from separation anxiety when you put them in bed, resist the urge to pull them back out of their crib. Try being comforting and reassuring, lightly rubbing their head while talking in a soft, soothing voice until they calm down, at which point you can quietly walk away and let them fall asleep.
If your baby is struggling to sleep or has many nighttime awakenings, the American Academy of Pediatrics advises talking with their doctor if you also notice:
Parents should discuss any abnormal breathing during sleep with their pediatrician.
Self-care is an important part of parenting, and that includes recognizing that nighttime awakenings or sleep regressions are common in babies.
Parents should set their expectations appropriately and remember that it takes time for babies to develop stable sleep patterns. Many babies don’t sleep through the night even at 12 months (10), so parents should avoid blaming themselves if their infant wakes up in the night. Self-care also includes thinking about tips to help parents get the sleep they need to feel more rested despite their baby’s sleep schedule.