Some newborn behaviors that concern parents are not signs of illness. They are usually due to an immature nervous system and will disappear in 3 or 4 months. Some common reflexes and behaviors include:

• trembling chin
• quivering lower lip
• having hiccups
• passing gas (this is not a temporary behavior)
• making noises when sleeping (from breathing and moving). Also during light sleep, babies can normally whimper, cry, groan, or make other strange noises. If you use a nursery monitor don't over-react to these normal variations in sleep sounds.
• sneezing
• yawning
• spitting up or burping
• stiffening of the body after a noise or sudden movement (also called the startle reflex)
• straining with bowel movements
• clearing the throat (or gurgling sounds in the throat)
• breathing irregularly (This is normal if your baby is content, the rate is less than 60 breaths per minute, any pauses are less than 10 seconds long, and your baby isn't turning blue. Sometimes babies take rapid, progressively deeper breaths to completely expand their lungs.)
• trembling or jitteriness of arms and legs during crying is normal. Convulsions are rare. During convulsions babies also jerk, blink their eyes, rhythmically suck with their mouths, and don't cry. If your baby is trembling and not crying, it could be abnormal. Give her something to suck on. If the trembling doesn't stop when your baby is sucking, call your health care provider immediately.