Newborn Leg Shaking: Is This Normal?

Newborns have an immature and changing neurological system, which can cause them to shake or tremble a bit. This is considered normal, and these tremors should subside as their nervous system develops. However, newborn leg shaking could also be a sign of a more serious condition, such as seizures, deficiencies, or low blood sugar. If you notice that your baby is shaking uncontrollably, seems distressed, or has a noticeable change in behaviour during an episode of tremors, it is important to seek medical attention.

Newborns' immature nervous systems

The nervous system is a complex system that regulates and coordinates body activities. It consists of two major divisions: the central nervous system (the brain and spinal cord) and the peripheral nervous system (all other neural elements). The nervous system is vulnerable to various disorders and can be damaged by blood flow disruption, immune system disorders, inborn genetic or metabolic problems, and toxic exposures or direct effects of drug exposures.

In newborns, an immature nervous system can cause jerky and twitchy movements, especially when they are trying to move their legs. This is because the signals from their brain to their muscles don't always arrive smoothly, resulting in shaky or twitchy movements. These movements will become more fluid as the baby's nervous system matures, usually by around 1 to 2 months old.

It's important to note that while newborn leg shaking is usually not a cause for concern, severe or prolonged shaking may indicate a nervous system problem. If you notice your baby's leg shaking, it's important to monitor the length of the shaking, any triggers, and any other symptoms your baby exhibits during the episode. If you are concerned, consult your baby's doctor.

Benign neonatal sleep myoclonus

The condition is considered harmless and is not associated with any neurological abnormalities. It is generally believed to be caused by an immature nervous system and usually resolves on its own within a few weeks to a few months. In rare cases, it may persist for several years.

The key characteristic of BNSM is that the jerks occur exclusively during sleep and immediately stop when the baby wakes up. The movements can be triggered by external stimuli such as noise, movement, or light, and they usually do not cause the baby to wake up. The episodes can last from a few seconds to 20 minutes or, in rare cases, even an hour.

While BNSM is typically benign, it can be mistaken for seizures, especially if the baby is the child of a mother with opioid dependency. Therefore, it is important to consult a medical professional if you notice any unusual movements or symptoms in your baby to rule out any potential underlying conditions.

Caffeine in breast milk

Breastfeeding mothers are advised to limit their caffeine intake to 200-300mg, or 2-3 cups of coffee, per day. Caffeine affects some babies more than others, and younger babies are more sensitive to it than older ones. Signs that your caffeine intake is affecting your baby include increased fussiness and irritability, and more trouble going to sleep or staying asleep.

If you suspect that your caffeine consumption is affecting your baby, experts recommend the following:

• Feed your baby before consuming any caffeine, and then wait at least three hours before breastfeeding again.
• Reduce your caffeine consumption to one cup of coffee per day.
• Quit caffeine altogether until you are done breastfeeding or until your baby is old enough to process it more quickly.

Caffeine can also affect the nutritional quality of breast milk. Mothers who drink three cups of coffee per day have about one-third less iron in their breast milk than mothers who don't drink coffee.

Low blood sugar

Newborn leg shaking is a common occurrence, and it is often a result of the baby's nervous system developing and adapting to life outside the womb. However, in some cases, it could be indicative of a more serious issue, such as low blood sugar, also known as neonatal hypoglycemia.

• Insulin in the blood: Insulin is a hormone that moves glucose from the blood into tissues. If there is too much insulin, it can lead to low blood sugar.
• Inability to produce enough glucose: The baby's body may not be able to produce sufficient glucose on its own.
• High glucose consumption: The baby's body may be using more glucose than it can produce or receive through feeding.
• Poor feeding: The baby may not be able to take in enough glucose through feeding.
• Premature birth or low birth weight
• Serious infections or need for oxygen right after delivery
• Slower growth in the womb during pregnancy
• Smaller or larger size than expected for their gestational age

Symptoms of low blood sugar in newborns can include:

• Bluish-colored or pale skin
• Breathing problems, such as pauses in breathing, rapid breathing, or grunting
• Irritability or listlessness
• Poor feeding or vomiting
• Problems keeping warm
• Tremors, shakiness, or seizures

If you suspect your newborn may have low blood sugar, it is important to consult a healthcare professional. They may perform a simple blood test to diagnose the problem and recommend appropriate treatment options. Treatment typically involves providing the baby with extra feedings of mother's milk or formula, and in some cases, a sugar solution may be given intravenously.

Seizures

While newborn leg shaking is usually harmless, it can sometimes be a sign of seizures. Seizures in newborns are rare but possible, and they are different from seizures in older children and adults. Here are some signs that newborn leg shaking could be a seizure:

• There is a noticeable change in your baby's breathing, heart rate, eye movement, or mouth movement when they shake.
• The movement can't be stopped by gently holding their leg.
• The episodes are identical each time.
• The movements are symmetrical and rhythmic.
• The shaking starts when there has been no change in the environment or your baby's posture, and they are not about to fall asleep.

If you suspect your baby is having a seizure, seek immediate medical attention. Seizures can be caused by low blood sugar, neurological conditions, or genetic disorders, and frequent seizures can lead to brain damage if left untreated.

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