What Is Baby Sleep Regression?


When your baby accepts a good sleeping routine, your troubles as a parent reduce dramatically. That is, until they suddenly and inexplicably rebel against this routine after just a few months. This can be a frustrating turn of events, but, luckily, there is an explanation for this behavior.

Perhaps your baby is undergoing what is commonly known as baby sleep regression.

Let’s take a look at exactly this sleep regression is, what the sleep regression ages are, and how to survive these unpredictable sleep regression stages. By the end, you’ll be better equipped to help your baby through these times.

What is Baby Sleep Regression?

Sleep regression is a variable period of time, where your child will suddenly wake up throughout the night or fight going to sleep after months of sleeping without issue.

Common signs of a baby undergoing this sleep regression include:

  • Frequent waking.
  • Shorter naps (that often last around 45 minutes or so).
  • Fussy when being put to sleep or upon waking.
  • Wakes up in the middle of their normal sleep cycles and has trouble falling back asleep.
  • Changes in feeding patterns.

Overall, you may notice that your baby’s sleep patterns have become worse.

18 month sleep regression

In reality, this behavior is not technically considered a “regression” whatsoever. According to Rachel Turner, a certified sleep consultant, a regression is when you revert to an earlier behavior, while this “sleep regression” is actually more of a progression. It’s simply your child’s way of developing their own circadian rhythm. Once they get through it, they’ll have a much healthier and longer sleep cycle, which they’ll likely possess for the rest of their life.


If your child is currently undergoing sleep regression, then it may help to find out the initial trigger for it. This will ensure you can address their ‘regression’ as best you can.


If this sudden change in sleep behavior is accompanied by clinginess or your child crying or moaning as if they’re in pain, then check if they are sick. A fever is the most obvious sign, of course, but not all illnesses result in a fever.

If you suspect your child is suffering from an illness, take them to their pediatrician as soon as possible.

Seasonal Allergies

Seasonal allergies may cause your baby to have difficulty breathing at night, which, in turn, will lead to them fussing and crying more often. Allergies may also result in snoring and sleep apnea, both of which definitely need to be checked out by a medical professional.

Food allergies and eczema may cause further pain while they sleep, leading to sleep regressions.

Physical Developments

Babies come to understand the world around them by learning how to roll, sit, stand, crawl, and walk. The stress of all these new developments can cause sleep regressions, especially if they wake up and roll around in their cribs during the night.

4 month sleep regression

Cognitive Bursts

With each new concept your child begins to understand, they may experience apprehension and insecurity about their newfound knowledge. This can then lead to separation anxiety and an increased need for reassurance from their parents at night.


Newborns and younger infants tend to sleep no matter their surroundings. Once they are old enough to become aware of their environment, however, sleeping in new places can stress your baby out.

Some babies will need more reassurance than others while travelling and settling back into their home. This can lead to baby sleep regression.

Changes in Sleep Needs

Your child’s sleep needs will change dramatically over their first five years of life. Though you may be forcing them to adjust to your sleep schedule, you should actually be accommodating theirs.

This doesn’t mean letting them stay up all night. Instead, you can help them through this difficult time by providing comfort when they experience trouble falling or staying asleep.


Exhaustion due to chronic sleep debt (or the amount of sleep you need to “catch up” on in order to reach a proper degree of sleep for the night) can raise your baby’s adrenaline and cortisol. This will make it difficult for them to fall and stay asleep.

If your baby can’t catch up on this very necessary sleep, their difficulties will only grow worse.

Baby sleep regression

Family Stress or Sudden Change

If your child undergoes any big life changes, such as entering daycare, having to share their parents’ attention due to the birth of a new sibling, parents’ divorce, or moving homes, their sleep patterns may change for the worse.

Some changes are just a part of life and you just cannot protect your child from them. They will experience some short-term stress from this change, but they will soon grow used to it if you’re there to constantly reassure them.

When Does Sleep Regression Start?

Sleep regressions will often coincide with significant developmental milestones, such as a sudden growth spurt or brain development. This can be stressful and frustrating for your baby, and their sleep patterns may reflect that stress.

The most common sleep regression stages are at four months, eight months, and eighteen months respectively.

Sleep regression

Four-Month Sleep Regression

The four-month sleep regression period occurs for nearly every baby and is often the hardest stage for parents to deal with. This sleep regression can occur as early as eight weeks old and as late as five months old.

This is by far the most important regression period, as it sets the stage for how your baby’s sleep cycle will be for the rest of their life.

Eight-Month Sleep Regression

This sleep regression stage can occur at eight months old or as late as ten months old.

Though not as common as the four-month or eighteen-month sleep regression, it may coincide with a period of significant brain development for your child (i.e. your child is learning to crawl, sit up, form words, etc.).

Eighteen-Month Sleep Regression

This sleep regression stage can occur anywhere between seventeen and eighteen months old.

You can usually attribute this last regression period to your toddler’s newfound sense of independence (i.e. walking on their own), the development of separation anxiety, or teething.

Sleep regression ages

How Long Does It Last?

Sleep regressions will last anywhere between one to six weeks, but they shouldn’t last any longer than that. If your child’s behavior has not improved after that, it’s possible that they may have developed some bad sleeping habits during the regression period.

Such habits may include needing to be rocked to sleep, fed to sleep, picked up and sung to, or other clingy habits that you may need to perform just to get them sleeping again.

Of course, these steps may be necessary to comfort and reassure your child throughout their development period. However, it’s wise to try and limit these habits in a careful, gentle way, so your child can learn to sleep more independently.

Can You Prevent Baby Sleep Regression?

Rest assured, all babies and toddlers will go through sleep regressions at some point in their young lives. It’s entirely common, and they may experience a few ‘relapses’ now and then.

This may be why medical professionals, including the American Academy of Sleep Medicine, have not agreed on what constitutes a sleep problem for babies. Some parents and pediatricians may think the exhaustive number of times they are awoken by their baby during the night is troublesome. Meanwhile, others may think this stretch of bad sleep is par for the course as far as infant care is concerned.

After all, a baby working out their circadian rhythm can make their sleep schedules unpredictable, even outside these normal sleep regression periods. Because of this inherent uncertainty, there is simply no way for parents to stop it from happening.

How to Survive Baby Sleep Regression

However, there are ways to lessen the intensity of your sleepless nights during these periods.

Sleep regression stages

Nap When They Nap

The most common piece of advice is to nap when your baby naps. Since bending them to your sleep schedule isn’t an option right now, you can simply follow theirs. That way, you gain some extra rest and are better prepared to care for them when they awaken.

Allow Them to Self-Soothe

Around three to four months (or around the time of their first sleep regression period), most babies will know how to soothe themselves to sleep.

This means that you need to give them this space to do so, even if this results in them crying along the way. Of course, some parents might deem this as cruel and opt to comfort their little ones even more instead. That is a perfectly valid option, if comforting your child is more your style.

The American Academy of Sleep Medicine, however, finds these “cry it out” methods to be generally effective, but only when done right.

If you want to try this method, start when your baby is six to twelve weeks old, then follow these steps:

  1. Comfort your baby until they become drowsy, but are not yet fully asleep.
  2. When they are on this tipping point, settle them into their crib and let them drift off on their own. Waiting until they are fully asleep may result in a sleeping habit that could be difficult for them to break later on.
  3. Once you’re sure they’re comfortably asleep, leave the room (unless you co-sleep in the same room).
  4. If your baby does wake up and cry, wait a few minutes before you get up and check on them. The amount of time you wait depends how long you are comfortable letting them figure out how to self-soothe. Start by waiting anywhere between one and five minutes before this initial check.
  5. When you check in on them, try to console your baby without picking them up. Don’t stay for any longer than two to three minutes doing so, even if they are still crying by the time these few minutes pass. Eventually, they will learn that you will always be close by, and fall asleep comforted by this fact.
  6. If they continue to cry for you throughout the night, however, you need to wait for a longer period of time before checking in on them again. For example, if you waited three minutes the first time, wait five minutes the second time, and ten minutes for each instance after that. The next night, wait five minutes the first time they wake, ten minutes the second time, and twelve minutes each time after that. Keep increasing the time until they learn to soothe themselves.

This may be hard for you at first, but most parents report seeing improvements by the third or fourth night, or up to a whole week later.

Create a Strict Bedtime Routine

Developing a routine before bed can help your baby associate that strict routine with sleepy time. Try these bedtime routine ideas and see if they work for you and your baby:

  • Save more active games for the daytime and quieter, calmer games for the evening. This keeps your baby from becoming too excited before bed, while tiring them out just enough to put them to sleep.
  • Many babies enjoy bathing right before sleep, because it helps to calm them down.
  • If your baby has a favorite activity, then save it for right before bedtime. This will help them associate this enjoyable activity with sleep, thus teaching them to like sleeping as well.
  • You need to be as consistent with these activities and routines as you can. This means doing the same activities in the same order every night, no matter how tedious. For example, it can involve nursing or rocking them in their crib at the same times every night. The routine helps them to relax and fall asleep, and changing that routine might stress them out.


While “regression” may not be the correct term for this behavior, baby sleep regression can be a real problem for exhausted parents everywhere.

Now that you know the signs and causes behind this behavior, you can care for your child with more confidence.


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