Sleep Regression: Why Your Baby Suddenly Won't Sleep (Complete Guide)
Sarah Mann·16 min read
Your baby suddenly refuses to sleep and you're running on empty?
There's a very good chance you're in the middle of a sleep regression. Every child goes through them in the first couple of years, some more intensely than others.
In this article you'll find out what a sleep regression actually is, when it usually shows up and how long it lasts.
You'll also get 6 tips for getting through a sleep regression, so your family can get back to calm, peaceful nights soon.
Let's start with the five most important questions about sleep regressions in babies:
1. What Is a Sleep Regression?
A "sleep regression" is a temporary phase (2 to 4 weeks) in which a baby or toddler suddenly sleeps much worse than before. Falling asleep becomes hard. Sleeping through the night stops happening. And daytime naps are suddenly far too short, or they disappear altogether.
2. What Causes Sleep Regressions in Babies?
Sleep regressions can be triggered by all sorts of things.
Very often your baby is going through a growth spurt or a whole developmental leap at the same time. That leap is a huge adjustment, and your baby needs time to process it. A lot of that processing happens at night, which is exactly when sleep falls apart.
Physical discomfort (teething and ear infections are the classics), bigger changes in your baby's world or a shift in the daily routine can bring on a regression, too.
3. How Long Does a Sleep Regression Last?
On average, a sleep regression lasts 2 to 4 weeks. In some cases it stretches to 4 to 6 weeks.
Of course, a lot depends on your baby. Every child is different and develops at their own pace.
In most cases, a sleep regression ends all by itself.
4. What Does a Sleep Regression Look Like?
A typical sleep regression affects far more than just sleep. It usually colors the whole day.
Besides the poor sleep, these are the classic signs:
More fussing and crying
A big appetite (frequent feeding is needed)
Serious clinginess and a strong fixation on mom (and dad)
Resistance to other caregivers or new people
Sleep itself can change during the day as well as at night:
Daytime Sleep
Your baby cuts naps short.
Your baby refuses naps.
Your baby skips a nap entirely.
Nighttime Sleep
Your baby suddenly struggles to fall asleep.
Your baby stops sleeping through the night.
Your baby wakes too early in the morning.
5. When Do Babies Have Sleep Regressions?
Most children go through sleep regressions at these ages: around 4 months, 8 to 10 months, 18 months and 2 years.
Smaller regressions can also show up at 6 months, 12 months and 15 months.
That said, both the timing and the intensity vary a lot from child to child. Sleep regressions usually go hand in hand with growth spurts and developmental leaps.
Sleep Regressions by Age
Here's what's going on at each stage, plus the best background and tips for that age:
Sleep Regression at 3 to 4 Months
At around four months, parents run into the notoriously tough 4-month sleep regression. What makes this one special is that the changes are permanent in most cases.
Your baby's sleep has reorganized itself, and the sleep cycles now look much more like an adult's. For many babies, that means waking several times a night between cycles. Naps often get shorter, too.
Baby sleep experts don't agree on whether a 6-month sleep regression really exists. Usually you can't pin down a typical multi-week phase with the classic regression signs at this age.
Even so, plenty of babies develop sleep problems around six months. Common causes are separation anxiety, newly discovered skills, overtiredness or teething.
Whether you call it a 6-month regression or simply "normal" sleep trouble, the effect is the same: babies fight sleep, wake often at night and refuse naps.
Eight to ten months is a different story. Here, pretty much everyone agrees that a regression is coming, and the reason is the enormous developmental jump babies make during this window.
Crawling, pulling to stand, starting to babble and understand words: these are huge adjustments for a little one.
On top of that, many babies cut their front teeth around this time, which can absolutely add a few rough nights.
Many parents see no signs of a regression in their baby at this age. For others, it's a completely different picture.
When sleep problems do show up here, growth spurts and developmental leaps are usually behind them. A lot of children start pulling up to stand or taking their first steps around now.
Sleep Regression at 15 Months
Is your child sleeping badly at around 15 months? At this age the cause is usually a change in the sleep rhythm. Toddlers give up their second nap and move to one nap a day, and that shift can bring real turbulence with it.
It gets even harder when your child refuses that second nap too early, before they're actually ready for one nap. That often happens somewhere between 12 and 14 months, and the result is a completely overtired toddler by evening.
Once the transition is behind you, this phase generally settles. What helps most here is a predictable daily rhythm and consistent routines around sleep.
This age can get intense all over again. Your toddler is speaking their first words and discovering that they have a will of their own. That last part is where it gets interesting.
Tantrums, little battles over bedtime, testing every limit. Your toddler is experiencing a brand-new sense of independence, and it spills straight into sleep.
Sleep problems here often get amplified by the nap transition (from two naps to one), by separation anxiety that can be very strong at this age, and by molars pushing through.
Is your two-year-old refusing to sleep or screaming at bedtime? Chances are good that a sleep regression is at play here, too. A developmental leap at this stage often leads to intense sleep problems.
Since your little one has discovered how satisfying it is to push boundaries and test their independence, bedtime can turn into a battle of wills.
This regression also tends to make toddlers dig in against daytime sleep. Some of them try to drop their nap entirely.
Making the Days Work
Don't be misled here. For the vast majority of children, this is not the right time to drop the nap. Serious overtiredness would follow, and with it a lot of trouble falling asleep and staying asleep.
The key is to lengthen the wake window before the nap a little, so your child is genuinely tired enough to sleep.
Beyond that, most parents have good experiences with sticking stubbornly to a daily schedule for their child, nap included. With that in place, this regression is very manageable.
What Else to Watch For
Another challenge can be fitting daycare into the picture. I hear again and again from parents that the daycare nap time doesn't match their child's rhythm. In our experience, it can do the little ones a lot of good to go to bed as early as 6:30 PM on those days.
You should also be prepared for separation anxiety and nighttime fears. It's not unusual for sleep to be disrupted by bad dreams, or by your child processing things that happened during the day.
This is a demanding stretch for many children, so it's worth saving bigger changes (moving to a big-kid bed, potty training) for a calmer phase, and definitely not doing them all at once.
6 Tips for Getting Through a Sleep Regression with Your Baby or Toddler
During a regression it isn't just the nights that are exhausting. The days can be just as demanding. Your little one needs a lot of reassurance, nursing or feeding, and attention.
Here are the survival strategies that matter most:
1. Remember, This Is a Hard Phase for Your Baby (or Toddler), Too
Your child needs extra attention and reassurance right now.
Since they're usually working through major developmental steps at the same time, and processing a lot, extra closeness and plenty of cuddling go a long way.
Give them additional security through predictable rhythms and routines. A consistent daily flow and a familiar bedtime routine matter enormously in weeks like these.
2. An Extra Feed
Don't be afraid of extra feedings. Growth spurts and sleep regressions usually arrive as a package deal.
So temporarily offering one more feed during the day, and at night too, makes sense in a lot of cases.
3. Don't Create New Sleep Problems
Easier said than done, but do your best not to establish new problematic sleep associations, meaning fall-asleep habits you can't or don't want to keep up long term.
Also watch out that you don't slide back into old patterns you'd already moved past.
When it comes to falling asleep, it helps a lot if your baby isn't already deeply asleep when you lay them down. Drowsy, but just barely awake, is the sweet spot.
That's what gives your child the chance to settle themselves and drift off on their own.
The lovely thing about it is that babies then learn to do the same at night, when they surface between sleep cycles.
4. Avoid Overtiredness
Do everything you reasonably can to keep your child from getting overtired. Falling asleep and staying asleep get much harder otherwise.
Where possible, hold on to your daily rhythm and bedtime routine. And if a nap simply isn't happening, a walk in the stroller can rescue it.
It also often helps to offer an earlier bedtime. Even 15 minutes can work wonders.
5. No Sleep Training
A sleep regression is not the time to start any kind of sleep training.
Give your baby 2 to 6 weeks to work through this mentally and physically demanding phase. After that, you can gently and actively start helping your child learn to sleep.
6. Take Care of Yourself, Too
I know how draining sleep regressions can be. I've lived through more than a few of them. So here's my tip: try to get help.
Especially when it's really rough, when you're getting no sleep at night and your child is extremely clingy during the day, it's genuinely wise to line up as much support as you can. Whether that's your partner, grandparents, friends or someone helping around the house.
No Improvement in Sight?
If your child's sleep hasn't improved after several weeks, you're usually not looking at a regression anymore but at a longer-standing issue with how your child falls asleep and stays asleep.
Then it's worth thinking about when and how you can help your little one fall asleep without your help. That's the key to better nights.
I hope you get through your sleep regression well and are back to lots of good sleep soon. If you still have questions about sleep regressions, take a look at the frequently asked questions below.
All my love and sweet dreams,
Sarah
Frequently Asked Questions About Sleep Regressions
Can I Stop My Child From Having a Sleep Regression?
Unfortunately there's no way to prevent a sleep regression, because it's part of normal development in babies and toddlers.
You can, however, take some of the edge off sleep problems, for example by keeping a predictable daily schedule and bedtime routine and by practicing falling asleep independently. Positive sleep habits like these can soften the effect that developmental leaps have on sleep.
It's also worth keeping in mind that sleep regressions are closely tied to meaningful leaps in your little one's development. Which makes them a reason to celebrate, if only we parents weren't far too tired for that.
Do You Have Tips for Heading Off a Sleep Regression?
You can't prevent sleep regressions entirely, but here's what helps:
Establish a bedtime routine. Humans love predictability.
Keep an eye on appropriate wake windows between naps, and on a fitting bedtime.
Make sure the sleep environment works: dark room, comfortable temperature.
Avoid letting your child get used to sleep associations you don't want long term.
Do All Babies Have Sleep Regressions?
While not all babies go through all of these phases, almost every family notices a clear change in their little one's sleep around the 4-month mark. Light and deep sleep phases become more and more pronounced, which raises the chances of your baby surfacing between them and needing your help to fall back asleep. (Worth reading, too: 10 reasons your baby keeps waking up, plus 12 solutions)
In the fourth month, a baby's sleep starts to look more and more like that of an older child or an adult. That change is permanent, and so, usually, are the sleepless challenges that come with it.
For all the other regressions, the good news is this: they're exhausting, but they're phases. And they are a natural and very important part of your child's healthy development.
Are There Studies on Sleep Regressions?
Sleep regressions are a completely normal, natural part of your baby's and toddler's development. They're closely tied to the other developmental leaps your little one is making.
We largely owe that insight to the pediatrician Dr. T. Berry Brazelton. Over the course of his work with 25,000 infants and young children, he studied early childhood development. His conclusion: early development isn't a straight line where each skill builds neatly on the last. It's more like a series of major reorganizations.
Just before these shifts, children seem (!) to go backward, before mastering a new milestone.
His observations and findings were later confirmed by neuroscientists. (www.nytimes.com)
A Good Sign!
So "regressions" in sleep and behavior are really the heralds of a rapid developmental leap, and you'll notice them shortly before or during the moment your baby or toddler reaches a new milestone.
When your little one is learning to roll, sit, walk or talk, those are all skills that demand an extraordinary amount from their brain and their body. They essentially need a while to reorganize themselves and get comfortable with the new abilities.
And after that, in most cases, sleep improves noticeably again.
Here is another study pointing to the typical sleep regression ages.
Do Sleep Regressions Go Away on Their Own?
Sleep regressions are phases. They usually last 2 to 6 weeks.
But not every baby goes through every one of these phases in the same way or with the same intensity.
Afterward, your little one's sleep normally improves on its own, unless they were always a light sleeper to begin with. The exception is the 4-month mark, where the effects on sleep can be permanent.
Where Can I Learn More About Sleep Regressions?
Understanding what's happening developmentally makes these weeks so much easier to carry. When you can connect the fussing and the extra neediness to a milestone your child is working on, it stops feeling like something is going wrong. And that makes it far easier to respond with patience instead of frustration.
Yes, and it's no coincidence that some sleep regressions land right around the time a baby's sleep rhythm changes. Babies need more guidance and more closeness from us during those windows.
The transition from three naps to two happens at roughly 6 to 8 months, and the move from two naps to one somewhere between 14 and 18 months.
How Do I Know If My Baby Is Having a Sleep Regression?
Babies are much clingier during these stretches. They fuss and cry a lot, fixate on mom and suddenly sleep far worse, whether that's falling asleep, staying asleep or napping. On top of that, you'll usually notice a bigger appetite.
With love, Sarah
About the author
Sarah Mann
Mom of seven. Certified Sensitive Sleep Consultant of the ISSC Australia. Founder of Land of Little Dreamers. Writing about attachment-friendly baby sleep for ten years, because it took her years to find her own way.
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