Tremors in Infant Legs

Tremors in infant legs can vary from baby to baby. But they’re usually quick, rhythmic shakes that last only a few seconds. These movements often look like a light shiver or jitter. It’s like your baby is quivering for a moment. Many parents describe these infant shivers as “jittery,” “wobbly” or “twitchy.”

Some babies have newborn leg tremors that come and go. Others have trembling legs that show up more when they’re tired, hungry or startled. These tremors are usually small and predictable. They stop on their own or when you gently hold your baby’s leg or pick them up.

Are tremors in infant legs normal?

Newborns make a lot of quick, jerky movements. Many of them look unusual if you’re seeing them for the first time. It’s understandable to worry when you see your baby’s legs shake or tremble. The good news is that most leg shaking is normal. It’s often just a sign that your baby’s nervous system is still developing.

Many newborns have little tremors. Especially when they’re falling asleep, stretching or waking up. These movements usually last only a few seconds and stop on their own. Most babies grow out of this shakiness by the time they’re about 3 months old.

Still, you know your baby best. If something doesn’t feel right, or if the shaking looks different from what you’ve seen before, it’s OK to reach out to your baby’s pediatrician. They can help you sort out what’s normal and what may need a closer look.

Why does my baby have leg tremors?

Seeing tremors in your infant’s legs can be unsettling. But most causes are harmless. They’re usually just a part of early development. Babies have immature nervous systems. Their bodies are still learning how to control small muscles. This can lead to brief shaking, shivering or jittery movements that come and go throughout the day.

Some reasons your baby may have leg tremors include:

Immature nervous system

The most common cause of newborn leg tremors is that your baby’s brain and nerves are still developing. In the first days and weeks of life, it’s normal to see quick, rhythmic shaking in your baby’s legs or arms. Many newborns have fine tremors as their bodies adjust to life outside the uterus.

These movements usually last only a few seconds and stop on their own. Most babies outgrow this type of leg shaking within the first few months of life.

Moro reflex

Babies are born with a strong Moro reflex (startle reflex). A sudden sound, movement or even a shift in position can cause their arms and legs to fly outward and shake for a moment. This can look like leg shivering in infants or a quick jerk of both legs at the same time. Tremors from the startle reflex usually affect both legs.

This reflex is normal and fades as your baby grows and their nervous system matures. It usually disappears by 4 to 6 months.

Benign sleep myoclonus

Many parents first notice leg shaking when their baby is asleep. Benign sleep myoclonus causes brief, rhythmic jerks during sleep. It can affect one leg or both. These movements stop as soon as your baby wakes up.

It can look concerning, but sleep-related tremors are harmless. Most babies outgrow them within a few months.

Low blood sugar

Some newborns have low blood sugar levels. This can happen if they’re born early, have trouble feeding or you have diabetes. When blood sugar drops, babies may look shaky, jittery or have trembling legs. You might also notice low energy, a lower body temperature or trouble waking up. Your baby’s pediatrician can test for and treat low blood sugar.

Sensitivity to stimulants

If you’re breastfeeding, your baby may react to caffeine or other stimulants in the food and drinks you consume. This can make them appear jittery or cause mild tremors. Reducing intake often helps. But this cause is usually mild and uncommon.

Less common but more serious causes

Rarely, persistent or unusual tremors may be linked to infantile spasms, metabolic disorders or other neurological conditions. These tremors look different from normal shaking. They may last longer or come with other concerning signs, like:

• Staring spells
• Eye movement abnormalities
• Changes in color or breathing

If you notice these symptoms, contact your baby’s pediatrician right away.

How can I manage or soothe leg tremors in my baby?

Most tremors in infant legs are harmless and don’t need medical treatment. But it’s normal to want to help your baby feel calm and safe when you see their legs shaking. The following tips can help you keep your baby comfortable:

• Let your baby sleep: If the shaking is mild and your baby looks relaxed, you don’t need to wake them. Many babies have trembling legs while they’re drifting off to sleep. Swaddling can help your baby feel snug and reduce sudden movements.
• Gently steady their body: Placing your hand gently on your baby’s leg or torso may help the tremor stop. Normal shaking legs usually settle when your baby is soothed or picked up.
• Check their breathing: Look to make sure your baby is breathing normally. Most harmless tremors happen without any changes in breathing, color or alertness. If anything looks off, seek care right away.
• Offer a pacifier or feeding: Sucking often helps stop mild jitteriness. If your baby accepts a pacifier, bottle or breast and their leg stops shaking, that’s usually a sign the movement is normal.
• Keep track of what you see: Use your phone timer, write down how long the shaking lasts or take a video if you can. Note what your baby was doing right before it started, and if anything helped it stop. This information can be helpful for your baby’s pediatrician.
• Watch for any other symptoms: If you notice changes in your baby’s behavior, color or breathing along with the leg tremors, call your baby’s pediatrician. These symptoms can help them decide whether more testing is needed.

When do baby tremors stop?

Most babies outgrow newborn leg tremors as their nervous systems mature. If the shaking lasts longer, seems unusual or continues as your baby grows, their healthcare provider can help you figure out what’s going on.

When to worry about leg tremors

Most tremors in infant legs are normal and short-lived. But it’s important to know when newborn leg shaking might be a sign that your baby needs medical attention. Trust your instincts. If something doesn’t seem right, it’s OK to reach out to your baby’s pediatrician. Seek care if:

• The leg tremors last longer than a few seconds
• The tremors don’t stop when you gently hold your baby’s leg
• Your baby has trouble breathing
• Your baby’s color changes
• Your baby seems upset or is unresponsive
• You notice other concerning symptoms, like trouble feeding, low energy or repeated episodes that happen close together
• You think the tremors might be infantile spasms or another type of seizure