Sleep Regressions: Why Your Baby Suddenly Won’t Sleep (and How to Survive It)
- Samantha Pieterse
- Sep 30
- 10 min read
Just when you thought you had finally figured out your baby’s sleep, bedtime routine working, and longer stretches at night, maybe even the occasional “they slept through,” everything suddenly unravels. Naps are shorter, nights are restless, and your once-sleepy little one now acts like bedtime is a personal insult.
If this sounds familiar, you’re probably in the middle of a sleep regression. Luckily (or unfortunately), sleep regressions are normal, temporary, and a sign of healthy development. They aren’t caused by bad habits, “spoiling” your baby, or doing something wrong as a parent. If you’re ever unsure whether your baby’s sleep changes are normal, you can always contact us for guidance.
Most sleep regressions last anywhere from two to six weeks, although the exact timing varies from child to child. The frustrating part is that it feels like forever when you’re living on coffee and wishful thinking, but the truth is, these phases really do pass.
What Is a Sleep Regression?
A sleep regression is a temporary phase when a baby or toddler who was previously sleeping well suddenly starts waking more often at night, fighting naps, or becoming fussier at bedtime. These changes usually happen during periods of rapid brain or body development, when your child is learning big new skills like rolling, crawling, walking, or talking.
The important word here is temporary. Sleep regressions don’t last forever. They reflect healthy growth and are not a sign that something is “wrong” with your baby or your parenting.
Is a Sleep Regression Normal and Does It Mean Something’s Wrong?
Parents often worry that sleep regressions mean they’ve created “bad habits” or done something wrong, when actually:
Sleep regressions are not a sign of illness.
Unlike infections or medical issues, regressions don’t cause fevers, rashes, vomiting, or ongoing pain.
Sleep regressions are not your fault.
They aren’t caused by rocking, feeding to sleep, or contact naps. Those might soothe your baby, but they don’t cause regressions.
Sleep regressions are not permanent.
Most regressions last 2–6 weeks, and once the new developmental skill becomes more routine, sleep generally settles again.
Sleep Regression or Illness: Knowing the Difference
This is where parents often get confused. Teething, growth spurts, and even illness can also disrupt sleep. Here’s how to distinguish them:
Teething
Often causes gum swelling, drooling, or a desire to chew on objects. Teething discomfort can wake a baby, but it usually improves with teething relief measures, whereas regressions persist regardless. If you’re wondering whether it’s teething instead, here’s a guide on what’s normal (and what’s not).
Illness
Look for red flags such as fever (≥38 °C), persistent vomiting, diarrhoea, ear pulling, or a widespread rash. These are not signs of a regression and should prompt a medical check.
Growth spurts
Babies may wake more frequently to feed, but usually settle again after a few days once their appetite levels out. A regression typically lasts longer and is linked to behaviour changes (clinginess, separation anxiety).
Why It’s Important to Understand Sleep Regressions
Sleep regressions can sometimes overlap with teething or growth spurts, making already tough phases feel even worse. That’s why it helps to know what you’re dealing with.
Understanding what a sleep regression is, and what it isn’t, lets you respond with confidence. It helps you avoid unnecessary worry about illness or guilt about “bad sleep training.” Most importantly, it’s a reminder that this is a developmental milestone, not a parenting failure.
Sleep Regression Ages: What to Expect and Why They Happen
Sleep regressions tend to follow your child’s developmental milestones. Not every baby hits them at the exact same time, and some babies may even skip a noticeable regression altogether. But there are certain ages when disrupted sleep is especially common. Each stage has its own triggers, typically linked to changes in the brain and body.
How long it lasts | Why It Happens | What to expect | |
|---|---|---|---|
The 4-Month Sleep Regression | Typically 2–6 weeks. | Around 4 months, a baby’s sleep pattern matures from “newborn sleep” into more adult-like cycles. This means lighter sleep stages (non-REM and REM) become established, and babies naturally wake more between cycles. | More frequent night wakings, even if they previously did longer stretches. Shorter naps. Increased need for comfort at bedtime. |
The 8–10-Month Sleep Regression | Often, 3–6 weeks. | Big leaps in mobility and social awareness occur here. Babies may start crawling, pulling up to stand, or even cruising along furniture. At the same time, separation anxiety peaks, as your baby begins to realise you can leave the room (and that’s not acceptable to them!). | Waking up just to check if you’re nearby.
Protesting at naps and bedtime.
Practicing new skills in the cot (standing). |
The 12-Month Sleep Regression | Usually 2–4 weeks. | Turning one often coincides with learning to walk. On top of this, some toddlers begin trying to drop a nap too soon. The combination of physical milestones and nap transitions makes sleep rocky. | Refusing naps (especially the second nap).
Night wakings when they start walking.
Extra clinginess, especially at bedtime. |
The 18-Month Sleep Regression | Roughly 2–6 weeks. | Around this age, toddlers go through a burst of language development, alongside emotional changes. Independence and testing limits become part of daily life, and yes, bedtime is one of those limits. | Bedtime resistance. Night wakings tied to new fears. Nap strikes. |
The 2-Year Sleep Regression | Commonly 2–6 weeks. | Toddlers are navigating big feelings, fears, and autonomy. They may experience nightmares, fear of the dark, or resistance to boundaries. Many are also transitioning out of the cot, which can add to the disruption. | Bedtime battles and delay tactics.
Night wakings due to fears. Sudden refusal of naps or early morning waking. |
The Significance of Each Sleep Regression Age
Each regression lines up with developmental growth, not bad habits. Babies and toddlers are processing new skills, emotional changes, and a rapidly developing brain. Sleep disruptions are a normal by-product of this progress, a temporary bump on the road to more settled sleep.
Signs of a Sleep Regression
Sleep regressions can look slightly different depending on your child’s age, but most share a few common threads. If your once-settled baby suddenly seems to have “forgotten” how to sleep, these are the signs to look for:
More Frequent Night Wakings
Your baby, who was giving you longer stretches, may start waking every couple of hours again. These wakings often happen between sleep cycles, and your little one may need more help settling back to sleep.
Nap Refusal
Daytime sleep can become tricky. Babies who used to nap well may suddenly fight naps or cut them short. Some toddlers even skip naps altogether, only to melt down later from overtiredness.
Sudden Bedtime Battles
Where bedtime used to be predictable, now it feels like a wrestling match. Your baby might cry as soon as you leave the room, or your toddler might pull out every stall tactic in the book (“one more story, one more sip of water”).
Increased Clinginess and Fussiness
Sleep regressions often overlap with developmental leaps and separation anxiety. This means your baby may want to be held more often, resist being put down, or cry whenever you leave the room.
How to Tell It’s a Regression (and Not Something Else)
Because many things can affect sleep, it helps to know the difference:
Regression: No fever, rash, diarrhoea, or persistent vomiting. Changes in sleep happen alongside new skills or behaviour, and usually last a few weeks.
Illness: Look out for fevers (≥38 °C), breathing difficulties, repeated vomiting, diarrhoea, ear pulling, or widespread rash. These are not regression signs and need a medical check.
Teething: May cause gum swelling, drooling, or chewing, but disruptions usually improve with teething remedies.
Growth spurts: Babies may wake more often to feed, but this usually settles after a few days.
Bottom line: If your baby is otherwise healthy, but suddenly clingier, fussier, and sleeping poorly, you’re likely dealing with a sleep regression phase, not a medical issue. Not sure if it could be an illness? Read how to spot dehydration and when to get help, or book a consultation online, and have our nurse check your little one out.
The Science of Baby Sleep
Understanding a little of the “why” behind sleep regressions can make them less frustrating. Babies aren’t trying to trick you, their brains and bodies are genuinely working overtime.
Baby Sleep Cycles
Adults cycle through light sleep, deep sleep, and rapid eye movement (REM) sleep approximately every 90 minutes. Babies do the same thing, but their cycles are much shorter, around 45–60 minutes in infancy. This means they naturally stir more often between stages of sleep, which is why they’re more likely to wake at night. As they grow, their cycles gradually lengthen and become more stable.
Baby Brain Development and New Skills
Sleep and brain development are closely linked. When babies are mastering big milestones, such as rolling, crawling, walking, or suddenly learning new words, their brains practice these skills even during sleep. This can make sleep lighter and more restless until the new abilities feel “settled.”
Sleep Hormones in Babies
Two hormones play a big role in regulating sleep:
Melatonin
The “sleep hormone,” which helps babies (and adults) feel drowsy when it gets dark. Newborns don’t produce much melatonin at first, but levels increase after a few months as their circadian rhythm develops.
Cortisol
The “stress hormone,” which rises when a baby is overtired or upset. High cortisol makes it harder to fall asleep and stay asleep. One reason overtired babies can seem even more wired.
Together, shorter sleep cycles, rapid brain development, and hormonal changes explain why regressions occur. They’re not random. They’re a reflection of healthy growth.
How a Sleep Regression Affects Parents
Sleep regressions don’t just disrupt babies. They take a real toll on parents as well. Broken sleep can quickly affect mood, concentration, and coping ability. Research shows that chronic sleep deprivation in the postnatal period is linked to higher rates of anxiety and postnatal depression, especially in mothers. Fathers and partners aren’t immune either. Disrupted sleep can increase irritability and lower patience for everyone in the household.
It can also place strain on relationships. Partners may feel frustrated, argue more often, or struggle to share the load equally when both are exhausted. Add work, other children, and daily responsibilities, and it’s no wonder many parents describe regressions as one of the hardest parts of the baby years.
The reassuring truth is that you’re not alone. Nearly all families experience at least one regression, and while it may feel endless in the moment, it always passes. With support, communication, and realistic expectations, most couples and parents weather this stage and often come out stronger for it.
We know how tough this stage can be. Don’t hesitate to reach out if you need support.
Sleep Regression Coping Strategies
There’s no magic trick to make a sleep regression vanish, but there are ways to make it more manageable. Think of this stage as survival mode. You’re helping your baby adjust while also protecting your own sanity.
Keep Your Baby’s Bedtime Consistent
Babies thrive on predictability. A simple routine: bath, feed, cuddle, sleep, helps signal that it’s time to wind down. Even if sleep is rocky, the consistency gives your baby a sense of security.
Create a Safe Sleep Space
Whether it’s a cot, crib, or safe room-sharing setup, a calm environment makes a difference. Keep the room dark, quiet (or use white noise), and comfortably cool. Following safe sleep guidelines reduces risks and helps you relax, too.
Gentle Settling Works
Rocking, shushing, feeding to sleep, or contact naps are not “bad habits.” They’re tools. If these soothe your baby during a regression, use them. Once the phase passes, you can ease back into other settling methods if you want to.
Share the Load
If possible, take turns with your partner or another support person. Even short stretches of uninterrupted rest can make you more resilient.
Support for Toddlers
Older toddlers may require a different approach. Comfort items such as a soft toy or blanket, a predictable bedtime routine, and extra reassurance if fears or separation anxiety are keeping them awake.
Remember: This Too Shall Pass
A regression feels endless in the moment, but it’s temporary. Survival strategies, yes, even feeding to sleep or holding your baby through a nap, won’t ruin their sleep forever. When the developmental leap settles, so does the sleep.
We’ve supported many families through these stages. Find out more about us here.
Sleep Regression Myths Busting
Sleep regressions come with plenty of advice, some helpful, some not so much. Let’s clear up a few of the most common myths.
“Sleep regressions aren’t real.”
They’re very real. While not a medical diagnosis, the term describes well-documented periods when sleep worsens around developmental milestones. Studies of infant sleep patterns confirm that these disruptions are linked to brain and body growth, not imagination.
“Your baby should be sleeping through the night by 6 months.”
Some babies manage longer stretches early, but many don’t, and that’s normal. Research shows that frequent night waking can persist well into the first year (and beyond) for healthy children. Every baby’s sleep journey is different.
“If you pick them up, you’ll spoil them.”
Responding to your baby’s needs builds trust and security. Holding or comforting them during a regression doesn’t create “bad habits.” In fact, responsive caregiving is linked to healthier emotional development.
“It’s always teething.”
Teething can disrupt sleep, but it’s not the explanation for every rough night. If sleep disruption lasts for weeks and lines up with new skills or developmental stages, it’s more likely a regression. Teething usually causes short-lived discomfort, not prolonged changes in sleep patterns.
The Light at the End of the Regression Tunnel
Sleep regressions can be overwhelming, especially when you’re running on fumes, but they are normal, temporary, and survivable. Every baby goes through phases of unsettled sleep, and every parent feels the strain. You are not alone in this.
These phases always pass. As your baby adjusts to new skills and milestones, their sleep settles again, often more predictably than before.
And while it’s hard to believe in the thick of it, there may come a day when you look back and actually miss those midnight cuddles, promise!
At Mums & Bums Centurion, We’re Here to Help
If you’re in Centurion and need extra support, whether it’s for sleep struggles, baby check-ups, or simply reassurance that you’re on the right track, we’d love to help.
👉 Book an appointment online or contact us today at Mums & Bums Mother & Baby Clinic, Centurion, where parents find trusted guidance and babies get the care they deserve.
FAQs About Sleep Regressions
At what ages do sleep regressions happen?
The most common ages are around 4 months, 8–10 months, 12 months, 18 months, and 2 years. These line up with big developmental milestones like rolling, crawling, walking, and language growth.
How long does a sleep regression last?
Most regressions last 2–6 weeks. Some children adjust faster, while others take a little longer, depending on temperament and milestones.
Is sleep regression the same as a growth spurt?
No. A growth spurt usually causes increased hunger and extra feeds for a few days. A sleep regression lasts longer and is linked to brain and skill development, not just appetite.
Do all babies go through sleep regressions?
Not always. Some babies have obvious regressions at the classic ages, while others glide through with minimal disruption. Both are normal.
How can I tell if it’s regression or illness?
Sleep regressions don’t cause fever, diarrhoea, vomiting, or rashes. If your child has these symptoms, it’s more likely an illness and should be checked by a healthcare provider.
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