When a baby shakes, particularly during feeding, it can be a source of immediate concern for parents. While such movements can be unsettling to observe, they are not always indicative of a serious underlying problem. Understanding the various reasons why a baby might exhibit shaking movements, ranging from common developmental stages to more concerning health conditions, can provide clarity and help parents determine when to seek professional guidance.
Understanding Normal Baby Tremors
Newborns often display temporary, involuntary movements, known as physiological tremors or jitters, as a result of their developing nervous systems. Many healthy newborns may experience fine tremors in their first few days of life. These normal tremors often appear as small, rhythmic movements of the chin, limbs, fingers, or toes.
These movements can be triggered by common factors like hunger, excitement, or crying. A baby might move their arms and legs more when hungry, and crying can also lead to trembling or stiffening. The startle reflex, also known as the Moro reflex, is another common cause, where a baby extends their arms and legs in response to sudden noises or movements.
Normal tremors typically cease when the baby is comforted, repositioned, or if the affected limb is gently held. They are usually brief, lasting only a few seconds, and tend to resolve on their own as the baby’s nervous system matures, generally by 3 to 4 months of age.
Potential Underlying Causes of Shaking
While many instances of a baby shaking are normal, some less common reasons can be more concerning. Low blood sugar, or hypoglycemia, is one such cause, particularly in newborns. Insufficient glucose levels can lead to shakiness. This condition is more prevalent in premature babies, those born to mothers with diabetes, or babies who are smaller or larger than average for their gestational age.
Temperature regulation issues can also manifest as shivering or trembling. If a baby is too cold, their body might shiver to generate warmth. Conversely, being too hot can also cause distress that might lead to involuntary movements.
Neonatal Abstinence Syndrome (NAS) can occur when a baby experiences withdrawal symptoms after intrauterine exposure to certain substances, most commonly opioids. Tremors, along with irritability and high-pitched crying, are common symptoms of NAS, which can appear within hours to several days after birth.
Seizures, including infantile spasms, are a more serious cause of shaking movements. Unlike normal tremors, seizure-related movements often involve one side of the body or are asymmetric. They may also be accompanied by eye deviation, fixed staring, or changes in consciousness or breathing.
Seizures might occur when the baby is quiet or asleep and usually cannot be stopped by comforting or repositioning the baby. Persistent or unusual shaking may indicate an underlying neurological condition.
When to Seek Professional Medical Advice
Parents should observe their baby’s shaking movements to help healthcare providers make an assessment. Noteworthy details include when the shaking occurs (during feeding, crying, or sleeping), how long episodes last, and what the movements look like (e.g., rhythmic, jerky, or one-sided). Observing whether the shaking stops when the baby is comforted or repositioned is also important. Parents should note any other accompanying symptoms, such as fever, lethargy, difficulty breathing, changes in skin color, poor feeding, or unusual eye movements.
Certain signs warrant immediate medical attention. These include shaking that does not stop when the baby is comforted or repositioned, or movements accompanied by staring, unresponsiveness, or changes in breathing. Shaking that is consistently one-sided or asymmetric, or shaking combined with fever, extreme fussiness, or unusual drowsiness, are also red flags.
For non-urgent situations, a regular check-up with the pediatrician is appropriate if tremors persist beyond 3 to 4 months of age. It is also advisable to consult a doctor if there are any general concerns about the baby’s overall development or well-being in conjunction with the shaking. Parents should also feel comfortable reaching out to their pediatrician with any concerns.