Is your baby twitching in their sleep? What’s normal and what’s not

If you’ve ever watched your baby sleep (and let’s be honest, you probably have!), you may have noticed them suddenly twitching, jerking, or seemingly jumping even while zonked out. These movements might look random, but they’re often part of a phenomenon known as sleep myoclonus — the medical term for brief muscle twitches that occur during sleep [].

These twitches are similar to that “falling” sensation adults sometimes feel right before sleep, called a hypnagogic jerk []. In babies, though, researchers believe these movements may play a role in neurological development, helping their brains learn how to move and control their growing bodies [].

In most cases, a little twitching or jerking during sleep is nothing to worry about — just your baby’s brain hard at work building movement skills.

Why do babies twitch in their sleep?

So what’s actually causing all that twitching while your baby sleeps? Usually, it’s linked to development — like reflexes, sleep cycles, or a maturing nervous system. 

Benign Neonatal Sleep Myoclonus (BNSM)

Benign Neonatal Sleep Myoclonus (BNSM) is a specific kind of sleep myoclonus that typically starts within the first six weeks of life []. BNSM is a harmless condition that can cause sudden, repetitive twitching while your baby sleeps. Though it may look alarming, this condition is not associated with seizures or developmental issues, and it usually resolves on its own by 6 months old.

Signs of BNSM include []:

• Rhythmic myoclonic jerks in the arms, legs, or trunk (but not the face)

• Movements that only occur during non-REM (quiet) sleep or “quiet sleep”

• No twitching when your baby is awake

• Movements that stop when your baby is gently woken

• Normal EEG and neurodevelopment

• May be triggered by rocking or repetitive sounds

BNSM doesn’t require treatment or testing, but if you’re unsure what you’re seeing, take a quick video of your baby’s movements and check in with your pediatrician.

Developing the brain and nervous system 

Many researchers believe that twitching during REM (active) sleep plays an important role in babies’ neurological development []. These movements may help your baby’s brain build motor pathways and learn how different body parts work together []. It’s all part of the brain “mapping” the body. And while it might look strange, it’s often a sign of healthy growth.

REM and non-REM sleep

During the first few months of life, babies spend about 50% of their sleep time in REM (rapid eye movement) sleep, also called “active sleep” []. This phase is light, unpredictable, and full of movement (think: fluttering eyelids, facial expressions, and twitching or jerking limbs) []. Many of these movements also show up during transitions between sleep cycles, when the brain briefly “wakes” before settling again.

Around 3 months, research suggests that twitches begin to appear during “quiet sleep” (non-REM) as well, often paired with bursts of activity called “sleep spindles []. Scientists believe this timing may help coordinate movement, strengthen motor pathways, and support neurological development []. 

Moro reflex (startle reflex)

Sometimes, when your baby suddenly throws out their arms, legs, or even jerks their whole body while asleep, it’s not just a random twitch. You may be seeing the Moro reflex, also called a “startle reflex" []. This involuntary movement is triggered by a sensation of falling, a loud noise, or even a shift in position and can happen when your baby is awake as well as asleep. It may look dramatic, but it’s a normal part of early development. It usually peaks at about 1 month, fades by the time babies are 2 months old [], and rarely persists beyond 6 months old []. 

When twitching might point to a medical issue

More often than not, your baby's twitching during sleep is harmless. But in rare cases, certain underlying conditions can lead to movements that look like twitching or jerking while they’re asleep. Below, we’ll break down the signs of less-common neurological conditions that may need a pediatrician’s attention. However, it’s important to note that most of the conditions below more commonly occur while babies are awake.

Neonatal seizures

Neonatal seizures are seizures that occur within the first 28 days of life, most often within the first week after birth []. They can be caused by a range of conditions, including brain injury, infection, or metabolic issues, and may be hard to recognize since their symptoms often look like typical newborn behaviors. Some neonatal seizures — like tonic seizures — can happen during sleep, though there are many types of seizures that are more commonly observed in babies while awake []. 

Possible signs of neonatal seizures include []:

• Sudden or repetitive eye movements, blinking, or staring

• Chewing, sucking, or tongue movements that seem unusual

• “Bicycling” or paddling leg movements

• Pauses in breathing (apnea)

• Rhythmic jerking or stiffening in one area of the body

• Quick, single jerking motions that repeat

• Movements that occur while awake and do not stop when touched or repositioned

If a provider suspects seizures, they’ll likely perform an EEG (brain wave test) and possibly imaging tests like an MRI to identify any underlying causes. Treatment may involve medication and supportive care. 

While some neonatal seizures are short-lived and mild, others may be a sign of more serious brain issues. Early diagnoses and treatment are key, so seek medical evaluation promptly if you notice any concerning signs.

Self-limited neonatal-infantile seizures

Self-limited neonatal-infantile seizures (previously called “benign familial neonatal-infantile seizures”) are a rare type of epilepsy that typically starts within the first few months of life []. These seizures occur in otherwise healthy babies who are meeting their developmental milestones and have normal brain imaging and neurological exams.

Signs of self-limited neonatal-infantile seizures may include []:

• Repetitive jerking on one side of the body, such as the arm, leg, or face

• Seizures that spread to both sides of the body

• Movements that occur in clusters

• Seizures happen during wakefulness, not during sleep

• A possible family history of similar early-life seizures

While these seizures can look alarming, they usually respond well to medication and tend to stop on their own by 1 - 2 years old. Most children with this condition develop normally. If you’re noticing jerking movements that happen when your baby is awake — especially if they seem rhythmic or one-sided — it’s a good idea to contact your pediatrician for an evaluation.

Infantile spasms

Infantile spasms are a rare but serious underlying neurological condition (a specific type of epilepsy) that can sometimes be mistaken for normal baby twitching []. These seizures typically begin between 3 - 12 months of age and often appear in subtle, clustered bursts, usually just after a baby wakes up, and rarely during sleep.

Signs of infantile spasms include []:

• Sudden stiffening or tensing of the body

• Repeated head drops, chin movements, or brief, jerky motions

• Eyes rolling up or pulling to one side

• Clusters of spasms with brief pauses between them

• Increased fussiness or silence after a spasm

• Loss of developmental milestones (e.g., rolling, sitting, babbling)

• Decreased social interaction or smiling

If you notice any of these symptoms, record a video and contact your pediatrician right away. Prompt evaluation and early intervention are key.

Not sure if it’s normal twitching? Here’s what to know

Your baby twitching in their sleep is often nothing to worry about. But when the movements seem unusual or are paired with other changes in behavior or development, it’s worth a closer look. 

This quick guide can help you tell the difference between twitches that are part of babyhood and movements that may require your pediatrician’s attention.

When to check in with your pediatrician

Generally, twitching during sleep is normal for babies, especially if it stops as soon as they wake up (except in the case of Moro reflex). But if something feels off — or the movements seem more intense, repetitive, or unusual — check in with your pediatrician for peace of mind.

Call your pediatrician if you notice:

• Twitching that continues when your baby is awake (outside of Moro reflex)

• Repetitive or rhythmic jerking, especially on one side of the body

• Movements that don’t stop when you reposition or touch your baby

• Signs of stiffening, unusual eye movements, or loss of developmental milestones

If any of the above is present, try to take a video of what you’re seeing. That way, your pediatrician can review it and help determine whether further evaluation is needed. It’s always OK to reach out and ask for help, even if it’s for your own peace of mind.

Should I wake my baby if they twitch during sleep?

In most cases, there’s no need to wake your baby if they’re twitching while asleep. These movements are usually a part of normal development and often happen during active sleep [] or as a result of the Moro reflex [].

If your baby seems well and is otherwise resting peacefully, it’s best to pause, observe, and let them sleep. 

What to do if your baby twitches or shakes while sleeping

Seeing your baby twitch or jerk while sleeping can be unsettling, but in most cases, there’s nothing you need to do. That said, there are a few simple ways to support your baby’s sleep (and your peace of mind!) while you keep an eye on their movements.

Observe 

A good first step is to watch without waking them. Most baby twitching in sleep is short-lived and resolves on its own. Pause and observe: Does your baby settle afterward? Are they breathing normally and waking up content? If the answer is yes, it’s likely nothing to worry about. And if something still feels off, it’s always OK to check in with your pediatrician (with a video of your baby’s movements, if possible).

Swaddle newborns

For newborns, can help reduce sudden movements triggered by the Moro reflex. A snug, breathable swaddle can make sleep feel more secure and reduce flailing or startling. However, swaddling won’t prevent all twitching, especially those related to REM sleep or neurological development.

Takeaway

• Babies twitching while asleep is expected. Most movements — like jerks, flails, or brief shudders — are part of healthy neurological development (likeREM sleep, or the Moro reflex).

• Watch without waking. If your baby looks comfortable and the twitching stops when they wake up or shift position, there’s no need to intervene.

• Some movements may need a closer look. Movements that are repetitive, one-sided, happen while awake, or are paired with other symptoms (like stiffening or loss of developmental milestones) should be evaluated by a pediatrician.

• When in doubt, take a video and reach out to your pediatrician. Getting reassurance is always OK!