"When a baby is born, his/her normal reflexes are immature resulting in them being overactive," Lewis explains. Trembling and quivering should come to a complete stop after this period. Overactive reflexes can result in chin and lower lip quivering as well as jittery limbs multiple times a day.

Is it normal for a baby to shiver?

As a new parent, it's easy to get worried when you see your 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, in most cases, your baby will outgrow them.

What happens when a baby shivers?

If a baby is forcefully shaken, his or her fragile brain moves back and forth inside the skull. This causes bruising, swelling and bleeding. Shaken baby syndrome usually occurs when a parent or caregiver severely shakes a baby or toddler due to frustration or anger — often because the child won't stop crying.