Observing a newborn’s lip quivering can be unsettling for new parents, often raising concerns about their baby’s well-being. This common occurrence in infants is a normal part of their early development, typically temporary and harmless. Understanding the reasons behind it can provide reassurance and help parents recognize when medical attention might be necessary.
Common Reasons for Lip Quivering
A primary reason for a newborn’s lip quivering stems from their immature nervous system. As the nervous system develops, it can lead to less coordinated muscle control. This immaturity can cause transient tremors or jitters, including in the lips and chin, as electrical signals from the brain are sent erratically. These movements resolve as the baby matures, often by three to four months of age.
Newborns also have an underdeveloped ability to regulate their body temperature. If a baby feels slightly cold, their body might respond with shivering or quivering, which can manifest as lip tremors. Ensuring the baby is adequately warm, such as by wrapping them in a blanket, can alleviate this type of quivering.
Strong emotions, such as hunger or being overwhelmed by new sensations, can trigger subtle tremors or quivering in newborns. For instance, an empty stomach due to hunger can lead to quivering lips. The developing body’s inability to efficiently regulate a rush of emotions or sensory input can physically manifest as these small muscle movements.
Some instances of lip quivering are part of normal newborn reflexes that fade over time. For example, lower lip quivering can be a reflex in response to a sudden noise, movement, or change in body posture. These involuntary movements are a sign of a healthy nervous system and diminish as the infant gains more voluntary control over their muscles.
When to Seek Medical Advice
While lip quivering is harmless, certain characteristics or accompanying symptoms warrant medical evaluation. If the quivering is persistent, increases in intensity, or becomes more frequent, it may indicate an underlying issue. For instance, if the trembling does not stop when the baby is sucking, it indicates a need to contact a physician.
Medical advice should be sought if lip quivering is accompanied by other concerning signs. These include lethargy, difficulty feeding, fever, or a bluish tinge around the lips or face. Abnormal eye movements, lack of responsiveness, or unusual muscle tone are also signs that require medical attention.
If the baby appears unresponsive or difficult to rouse during or after an episode of quivering, professional guidance is necessary. If the quivering resembles seizure-like activity, such as being rhythmic, non-stopping, or not easily interrupted, contact a doctor. Parents should trust their instincts and consult their pediatrician if they are worried.
Differentiating From Other Newborn Movements
Distinguishing normal lip quivering from other types of newborn movements can help parents assess the situation accurately. Normal lip quivering stops when the baby is touched, repositioned, or distracted, or when given something to suck on. In contrast, true tremors or seizure-like activity may not cease with these interventions.
Normal lip quivering is isolated to the lips or chin. More concerning movements, however, may involve other parts of the body or be more generalized. For example, seizures in newborns can involve muscle jerking, eye blinking, and rhythmic sucking movements of the mouth, and babies do not cry during seizures.
The Moro reflex, also known as the startle or embrace reflex, is another common normal movement that can be confused with tremors. This reflex involves a brief stiffening of the body, straightening of the arms, and opening of the hands in response to a sudden noise or movement. Unlike lip quivering, the Moro reflex involves a more widespread body response.