Newborn Tremors: What's Normal And What's Not?

It is understandable for new parents to worry about their newborn's odd, shaky movements, from quivering chins to trembling hands and jitters to jerky arm and leg gestures. In most cases, these extra movements are completely normal and harmless, and the baby will likely outgrow them. However, it is important to understand the difference between normal baby shakes and a more serious issue, such as seizures.

Shaking is often a normal part of a newborn's development

It is understandable for new parents to worry when they see their newborn's odd, shaky movements, from quivering chins to trembling hands and jitters to jerky arm and leg gestures. However, in most cases, these extra movements are completely normal and harmless, and it's likely that your baby will outgrow them.

Fine Motor Skills Development

Different parts of a newborn's body tend to twitch at different developmental stages, and this can be expected as a natural part of fine motor skills development. For example, during the neonatal period (the first 28 days of life), shaking of the head and extremities prepares babies for holding up their heads. In older babies, twitching of the wrists and fingers may be part of the development of fine motor skills.

Immature Nervous System

In newborns, the pathways that carry signals from the brain to the body are not yet fully developed, causing jerky and twitchy movements. As the baby's nervous system matures, by around 1 to 2 months old, these movements will become more fluid.

Startle (Moro) Reflex

If a baby is suddenly surprised by a loud noise or other environmental stimulus, they might exhibit an involuntary movement in which they extend their arms, legs, and fingers and arch their back for a few seconds. This is called the Moro reflex, or startle reflex, and is common until the ages of 3 to 6 months. Swaddling or using a sleep sack can help curb the reflex during naps.

Caffeine in Breast Milk

If you are breastfeeding and consuming a lot of caffeinated beverages such as coffee or soda, it may cause the baby to twitch or jitter. While a little caffeine (up to 300mg, or about two to three cups of coffee) is not a problem, large amounts can pass to your baby and build up in their body.

Sleep Twitching

Shaky and twitchy movements are also likely to occur when a baby is falling asleep or waking up. This is likely a benign condition known as sleep myoclonus, or nocturnal myoclonus, and it usually occurs at the moment of dropping off to sleep. External stimuli such as noise, movement, or light can also cause these movements. Sleep myoclonus usually resolves within a year and there are no inherent consequences or reasons for concern.

Other Causes

There are other reasons for baby tremors, including being cold, as well as having low blood sugar. Other signs of low blood sugar, or hypoglycaemia, can include a blue tint to the skin or lips, lethargy, and/or lack of interest in feeding.

Shaking can be caused by caffeine in breast milk

Shaking in newborns is usually a normal part of their development. However, caffeine in breast milk can also be a cause of shaking in newborns.

Caffeine is a natural stimulant found in over 60 plants, including coffee, tea, and chocolate. It is often consumed to increase alertness and energy levels, which can be especially helpful for new mothers who are adjusting to a lack of sleep. While caffeine is generally safe for breastfeeding mothers to consume, it can pass into breast milk and affect infants.

The amount of caffeine that passes into breast milk varies from mother to mother, with some studies finding that approximately 1% of the total amount of caffeine consumed is transferred. While this amount may seem small, infants take much longer to process caffeine than adults. In healthy adults, caffeine stays in the body for three to seven hours, while infants can retain caffeine for 65 to 130 hours, or even a few days. This means that even small amounts of caffeine can build up in an infant's body over time, especially in newborns.

The effects of caffeine on infants include increased fussiness and irritability, as well as trouble sleeping. Younger babies are more sensitive to caffeine, and large amounts can cause twitching or jitteriness. While a little caffeine is not a problem, excessive intake can lead to negative consequences. Mothers who drink three cups of coffee per day have been found to have about one-third less iron in their breast milk than those who don't consume caffeine. Additionally, caffeine intake above the recommended limit may decrease weight gain in exclusively breastfed infants.

To minimise the impact of caffeine on your infant, it is recommended to feed your baby before consuming any caffeine and then wait at least three hours before breastfeeding again. This allows your body enough time to process the caffeine and reduce the amount that passes into your breast milk. It is also suggested to limit caffeine intake to 300 milligrams per day while nursing, which is equivalent to about two to three cups of coffee.

Shaking can be a sign of infantile spasms

Shaking in newborns can be a source of concern for parents, but it's important to understand that in most cases, these extra movements are completely normal and harmless. However, there are instances where shaking can indicate a more serious issue, such as infantile spasms.

Infantile spasms are a rare form of childhood epilepsy, affecting approximately 1 in 2,000 infants and children in the United States each year. They are characterised by tiny seizures that can significantly impact a baby's development. These seizures often manifest as sudden stiffening of the muscles, with the baby's arms, legs, or head bending forward. The seizures are typically brief, lasting only one to two seconds, but they can occur in clusters, with multiple spasms in a row.

Infantile spasms usually occur when a baby is between 3 to 12 months old, with the peak age range being 4 to 8 months. They can be subtle and easily overlooked, sometimes resembling a normal startle reflex or colic. During a spasm, a baby may stiffen and extend their arms while scrunching up their knees or bending their neck forward. In some cases, it may appear as a mild head bob or the baby's eyes rolling up.

The underlying causes of infantile spasms vary and can include genetic or metabolic disorders, brain injuries, or conditions such as Down syndrome or tuberous sclerosis. In some instances, no identifiable cause is found.

If you suspect your baby is experiencing infantile spasms, it is crucial to seek medical advice promptly. Early diagnosis and treatment are critical to stopping the seizures and minimising their impact on your baby's development. You can help your doctor by recording videos of the spasms, documenting when they occur, and tracking changes in your baby's developmental milestones.

While shaking in newborns is often a normal part of their development, it is always better to be cautious and consult a healthcare professional if you have any concerns.

Shaking may be a symptom of low blood sugar

Shaking in newborns is usually a normal reflex known as the startle or Moro reflex. However, in some cases, it may be a symptom of low blood sugar, or hypoglycemia.

Low blood sugar in newborns can occur for several reasons. One reason could be that the mother's blood sugar levels were poorly controlled during pregnancy, which could be due to diabetes. Other reasons include the baby being born prematurely, the baby being larger or smaller than expected for their gestational age, or the mother and baby having incompatible blood types.

The symptoms of low blood sugar in newborns may not always be obvious. Some of the most common signs to look out for include a blue tint to the skin and lips (cyanosis), pauses in breathing (apnea), low body temperature (hypothermia), floppy muscles (poor muscle tone), lack of interest in feeding, and lethargy. If you suspect your baby might have low blood sugar, it is important to seek medical advice as soon as possible.

Low blood sugar in newborns can usually be treated by providing the baby with a fast-acting source of glucose. This could be in the form of a glucose and water mixture, formula, or glucose given through an IV. It is important to monitor the baby's blood glucose levels after treatment to ensure their levels remain stable.

In summary, while shaking in newborns is typically a normal reflex, it could sometimes be a symptom of low blood sugar. If you are concerned that your baby is exhibiting signs of low blood sugar, it is crucial to consult a healthcare professional for proper diagnosis and treatment.

Shaking may be a symptom of seizures

Seizures can be difficult to diagnose in newborns as the signs may mimic normal movements and behaviours seen in healthy babies. For example, chewing motions, bicycling movements, and sudden jerking of the arms and legs are all normal reflexes in newborns that can also be symptoms of seizures. Other signs of seizures in newborns include:

• Random or roving eye movements, eyelid blinking or fluttering, eyes rolling up, eye opening, or staring
• Sucking, smacking, chewing, and protruding tongue
• Unusual bicycling or pedalling movements of the legs
• Thrashing or struggling movements
• Long pauses in breathing
• Rhythmic jerking movements that may involve the muscles of the face, tongue, arms, legs, or other body regions
• Sustained stiffening or tightening of the muscles in one area or the whole body
• Turning the head or eyes to one side, or bending or stretching one or more arms or legs
• Quick, single, or arrhythmic repetitive jerking motions involving one arm or leg, or the whole body

It's important to note that seizures in newborns can have serious consequences and may indicate a more serious underlying condition, particularly a brain injury. Therefore, if you suspect that your baby is having seizures, seek specialised medical care immediately.

Frequently asked questions