The 4 Month Sleep Regression: Why It Happens, And What You Can Do About It

Amber LoRe - Sleep Consultant / Pediatric sleep consultant / Updated May 04, 2021
Baby in mom's lap holding hand

Babies often see a big change to their sleep habits around 3-4 months old.  Just as your baby leaves the newborn stage and their sleep patterns start to become more predictable - bam - you may see a big shift. Sudden increases in night waking, short naps, fussiness, or fighting sleep? Yup - the 4 month sleep regression is probably to blame.

But not to worry - whether you’re dreading your baby’s first sleep regression, or are already in the midst of it, we’re here to help guide you through this important developmental milestone.


IN THIS ARTICLE:


When babies are around 3-4 months old, their sleep patterns start to mature. Rather than continuing to sleep as a newborn, their patterns now have additional cycles of light sleep and deep sleep. The so-called sleep “regression” happens because your baby starts to wake fully between these cycles, and needs help falling back to sleep.

It’s also important to note that at this stage, changes in sleep are caused by a biological change in the way a child sleeps, rather than a regression caused by a temporary state. To put it simply, your baby may be waking more because they’re growing and developing - not because they’re going backward.

By this age, babies begin to produce melatonin, which helps to regulate our sleep-wake cycle. While a newborn’s sleep isn’t strongly controlled by circadian rhythm (our internal “body clock” that helps control sleep), that all starts to change at this age. Sleep begins to mature, and babies start sleeping in more stages and cycles, similar to the sleep patterns of an adult.

Once a baby starts to cycle through light and deep sleep, they’ll have a brief period of wakening after each cycle. While this period of wakefulness can lead to new sleep challenges (we’ll get to that in a second!), it’s actually a pretty cool built-in protective mechanism, and allows the body to check in on its environment, making sure everything is  safe and sound throughout the night.

It’s those brief awake periods that can cause a lot of disruptions to sleep and lead to the dreaded 4-month regression.

This is how it typically plays out: your baby falls asleep in your arms/a swing/bouncy seat and is then moved to the crib. Later, when they wake up in between sleep cycles and their environment is different from the way they fell asleep, this causes them to wake fully (rather than fall back to sleep on their own and shift onto the next sleep cycle).

Once fully awake, they often want some help from you so they can get back to sleep. Another cuddle sounds way better than closing their eyes and doing it themselves, especially if they haven’t practiced the skill of falling asleep on their own. Needless to say, this can be extremely disruptive to a family’s sleep if that happens repeatedly throughout the night.

Think of it this way - you fall asleep with a pillow, but when you wake up during the night, it’s mysteriously vanished. You’d want that pillow back, and might have a hard time returning to sleep without it. However, if your pillow had remained under your head, you’d be able to just roll over and fall back to sleep.

Sleep regressions typically last 2-6 weeks. Improving sleep after the 4 month regression depends on how quickly a baby is able to develop healthy sleep habits and be physiologically ready to link sleep cycles on their own.

The 4 month regression begins around 3-4 months of age, when a baby begins to cycle between light sleep and deep sleep, similar to an adult, rather than the more constant state of sleep of a newborn. (Newborns tend to sleep in two sleep stages, compared to the four sleep stages of sleep after 4 months of age.) This maturation in sleep can suddenly lead to multiple wakings at night and short naps - although it doesn't significantly disrupt sleep for ALL babies.

Babies typically start sleeping better when they follow an age appropriate schedule, are developmentally able to link sleep cycles, and learn how to fall asleep independently. With the right guidance, most babies are able to master falling asleep on their own by 5-6 months old, if not sooner. 

Custom plans for better sleep

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Unfortunately, this regression can sometimes lead to short naps. Babies often wake after 30-45 minutes of sleep and are unable to fall back to sleep without help.

Since sleep is critical for brain development and overall health, we don’t want anyone missing out on sleep if they don’t have to. Whether you’ve started to notice sleep changes or not, here’s what you can do to make the transition smooth:

  1. Consistent pre-bedtime and pre-nap routines are an effective way to let your baby know what to expect at sleep times. A calm, predictable routine can also help relax your baby and prime them for sleep.  A bedtime routine might look like this: breastmilk or formula feeding, a bath/wash up, change into a dry diaper and pajamas, and read a story before bed. When the same set of activities are done in the same order each time, children can predict what comes next, which adds to their sense of security. This can make the  transition to sleep much easier.

  2. One of the best ways to prevent babies from waking frequently at night is to help them learn to fall asleep at bedtime under the same conditions they’ll experience for the rest of the night. If your goal is for baby to spend most of the night in their crib, give them some practice falling asleep there. If they tend to fall asleep in your arms (or another sleep surface), you’ll want to give them the time and opportunity to adjust to falling asleep in the preferred sleep space.

  3. Helping your baby learn to fall asleep independently is probably the most important step you can take to reduce the impact of the 4 month regression. Babies who are able to fall asleep without external help (such as patting, rocking, or feeding to sleep) can use those same skills to link sleep cycles during the night and after a short nap. This translates into longer periods of sleep. 

  4. Blackout curtains might be one of our favorite inventions. Since light exposure helps tell our internal clocks when to wake up, a really dark bedroom can mean longer naps and later wakeups, especially during when it’s light outside. After the 4 month regression, sleep tends to be very light in the early morning hours, and children wake easily. If a baby sees light during this time period, it can signal their body to start waking early every morning. Darken the room to help prevent sunlight from turning your little angel into a little rooster.  A dark room can also help lengthen naps. Once their sleep has matured, babies tend to wake after one sleep cycle. If the room is too light, they can become distracted by their surroundings and fully wake up; a dark room can help encourage them to link their sleep cycles and fall back to sleep.

  5. It seems like babies should just fall asleep when they’re sleepy, right? Unfortunately, that’s not always the case. Babies fall asleep most easily when they’re tired, but not overtired. When babies stay awake too long, they tend to cry more at bedtime and have a harder time falling asleep and staying asleep, thanks to a release of hormones. Fortunately, giving your baby the opportunity to snooze within the appropriate wake window can help them stay asleep longer, and fall asleep more easily. Sleepy cues can be helpful in figuring out the best time, but not all babies give clear signals that they’re ready for sleep. Others might give you cues, but by the time you’ve gone through the routine, you’ve missed your chance, and baby seems wide awake again.  Figuring out the right wake windows can be tricky. Huckleberry’s SweetSpot® sleep predictor makes finding the optimal nap and bedtime easier, even letting you toggle between the number of naps each day if your child is in the midst of a nap transition. Install our app today!

  6. Babies can make a lot of noise in their sleep! If your child starts to stir in between cycles, don’t assume they immediately need your help. Many will fall back to sleep on their own after a few minutes if given the chance.

  7. If your baby suddenly starts waking frequently at night, you may wonder whether they’re hungry, or just want to soothe themselves back to sleep by sucking. To complicate matters, many babies go through a growth spurt around this time, and genuinely do need to eat more.  Around 3-4 months, we find that many babies still need one to three feedings at night. Waking more than that is often the result of a sleep association or overtiredness. Examine whether they have a feed-to-sleep association at bedtime. If they fall asleep on the breast or bottle, they’ll be more likely to want that help when they wake between sleep cycles during the night. Consider whether you can offer more milk or formula during the day to help curb true hunger at night. You might offer bigger feeds during the day, cluster feeding before bedtime or a dream feeding before your bedtime. Speak with your pediatrician and/or lactation consultant regarding your child’s individual dietary needs. 

  8. There are plenty of steps you can take to improve sleep around 3-4 months old. However, don’t expect sleep to be flawless at this age. Not all babies can learn to consistently fall asleep on their own yet - this skill takes time, and not all babies are physiologically able to do so until 5-6 months of age. Babies this age typically aren’t ready to sleep for 10-12 hours straight without some help. Likewise, you’re likely to continue to see some short naps for a while. While some babies are capable of amazing feats of sleep at 3-4 months old, most of us will need to continue to give our babies the space to practice without the expectation of perfection.

Sleep issues can be complicated! Let our data scientists and sleep experts get to work on developing a program specifically designed with your family’s challenges and goals in mind. Our customized schedules are based on your child’s individual sleep needs, and designed to help minimize overtiredness. We’ll also provide guidance on helping your child develop (and strengthen) their independent sleeping skills, which is the most important step you can take to move past the 4 month regression. 

Change is the only constant in life -- especially when it comes to parenting. Luckily, the team at Huckleberry has your back through all the sleep changes ahead, from dropping naps, to sleep-space transitions, to improving sleep in general. Let’s do this together!

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4 month sleep regression FAQ

Q: Do all babies have a sleep regression at 4 months?

A:

No. Some babies experience sleep disruptions at 3 months, and other babies aren’t affected at all.

Q: Does the 4 month sleep regression pass?

A:

Yes! Once a baby learns to fall asleep on their own, they typically start sleeping for longer periods of time at night.

Q: Why is my 4 month old baby not sleeping?

A:

A maturation in the sleep cycle occurs between 3-4 months old, which can cause a baby to wake more often at night, and have shorter naps. This is especially true when a baby relies on parental help to fall asleep and/or is overtired at bedtime.

Q: How can I prepare for the 4 month sleep regression?

A:

Start helping your baby learn to fall asleep independently by giving them opportunities to go into their sleep space while they’re sleepy, but not asleep. When a baby regularly gets enough sleep during the day and has independent sleeping skills, they’re more likely to continue sleeping well throughout this developmental change.

Q: Is the 4 month sleep regression a myth?

A:

We wish! It’s common for many babies to begin to sleep for 5-8 hour stretches at night around 3 months of age, only for their caregiver to be surprised by the 4 month sleep regression.

Q: Do all babies experience a sleep regression at 4 months?

A:

No, they don’t. All babies experience the maturation of the circadian rhythm that causes children to sleep in stages and cycles (similar to an adult). However, not all babies will see sleep issues as a result.

Q: Does swaddling help with the 4-month-old sleep regression?

A:

We recommend transitioning away from swaddling once a baby starts to roll, or when they’re learning independent sleeping skills. Since teaching your baby how to fall asleep without help is one of the best ways to combat sleep problems caused by the 4 month regression, we don’t recommend starting to swaddle your baby at this age.

Q: My 4 month old baby won't sleep unless held. What should I do?

A:

It’s natural, and fairly common, for babies to want to be held for sleep. However, we understand how exhausting it can be! We recommend giving your baby the opportunity to practice sleeping in the crib at least once each day. This will help get them accustomed to sleeping flat on their back in their own sleep space. This may result in a short nap, which is okay at this stage - you can hold them for the next nap (so it’s longer) and try again the next day. With time and practice, they’ll be able to transition to sleeping longer periods without being held.

Custom plans for better sleep

Easy-to-follow steps that really work from pediatric sleep experts with your sleep goals in mind. Don’t let another sleepless night pass you by.

Created Aug 26 2019