There you sit with Baby fast asleep in your arms. All is calm until you put him in his bed. He throws his arms out and wakes up all bug-eyed with a look of surprise. What startled him? Worry not, newbie Mom. Your little guy is experiencing the Moro reflex. This is only one of several newborn reflexes, or primitive reflexes, he’s born with.
According to Jonathan Spanier, M.D., a pediatrician with Tennessee Pediatrics (which provides primary care for infants, children and teens in Hendersonville, Murfreesboro, Nashville and Thompson’s Station), one’s body performs a quick reflex in response to a stimulus. It’s an involuntary reaction, too. While most involuntary reflexes develop as you get older, you are born with others.
Spanier says these primitive reflexes help Baby survive and adapt to his new environment. They, too, are involuntary and are part of his immature nervous system.
“As Baby matures and his brain develops, these reflexes disappear and voluntary movements replace them,” adds Spanier.
Your pediatrician may asses these normal newborn reflexes to ensure Baby’s nervous system is normal. An absent or asymmetrical reflex can indicate a problem with his muscles, brain or nerves.
Get to know eight common newborn reflexes with detail into what they are and how long they last.
The Moro Reflex
When Baby presents a reflex and he gives a startling look, it’s called the Moro reflex — sometimes known as the “startle response.” Loud noises such as a doorbell or a dog bark, an accidental bump of the crib, a bright light or even his own cries are just a few things that trigger this reflex. It may even wake him from his sleep. Spanier says the Moro reflex may have been developed as a baby’s “alarm system” to alert him to unpleasant stimuli.
Appearance: Baby throws his head back, straightens his arms, opens his hands and then brings his arms back in (as if in an embrace). Cries may also follow. Pediatricians may test for the Moro reflex by supporting Baby’s head and letting it drop slightly. An asymmetrical Moro reflex may indicate a brachial plexus injury or clavicle fracture.
“An exaggerated Moro reflex can be seen in babies who are undergoing withdrawal from drugs used during pregnancy, such as narcotics,” adds Spanier.
Duration: Present at birth, this reflex lasts until Baby’s 4 to 6 months old. Swaddle him for his first few months of life to help prevent it.
If he retains the Moro reflex, it can result in over-sensitivity to light, noises, textures and other stimuli. It can also lead to problems with impulse control, sensory processing disorders, motion sickness and anxiety. It can also cause symptoms that overlap with typical ADHD signs, such as fidgeting, inability to sit still, poor focus and impaired impulse control.
The Babinski Reflex
Try to tickle Baby’s foot. Notice how he has an unusual reflex to your touch on the bottom of his foot? The Babinski reflex is another normal reflex for Baby.
Appearance: Stroke the sole of Baby’s foot and watch his big toe bend up toward the top of the foot as the other toes fan out. It’s actually an opposite reaction of the normal adult response in which the big toe flexes down.
Duration: The infant Babinski reflex can last till about 1 year of age. It can appear again in adults who suffer from brain damage or a stroke.
The Rooting Reflex
You may notice that when you hold Baby, he seems to rub his face into your arm or chest. This is called the rooting reflex and it’s a meant to help him find the breast or bottle for feeding.
Appearance: Stroke the corner of Baby’s mouth, he then turns his head toward the side you touch and open his mouth.
Duration: This reflex actually develops while Baby is in the womb — at around the 28th week of pregnancy. It is also present at birth and lasts until around 4 months of age.
The Suck Reflex
Another reflex that helps Baby with eating is the suck reflex.
Appearance: Touch the roof of Baby’s mouth and see how he starts to suck your finger.
Duration: It, too, develops while Baby is in the womb — at around the 32 - 36 weeks of pregnancy. Because of this, babies who are born prematurely may have difficulty sucking at first. This reflex lasts until 2 - 4 months of age, after which Baby should suck by choice and may start to refuse the bottle or breast more.
The Asymmetrical Tonic Neck Reflex
This reflex is a way to prepare Baby’s body for hand-eye coordination.
Appearance: Baby’s head is turned to one side with the arm on that same side straight. The opposite arm flexes, and he assumes what looks like a fencer’s position.
Duration: It’s usually present at birth and resolves by 4 - 6 months of age, when he’s ready to start rolling over. If he retains this reflex, it can cause problems with the development of normal hand-eye coordination.
The Palmar Reflex
You know how ticklish hands can be, so test this one out on your newborn.
Appearance: The Palmar reflex occurs when you stroke Baby’s palm and he closes his fingers in a grasp that can be quite strong. Although this is an involuntary reflex, hold his hands to help build your bond with him.
Duration: This reflex is present at birth and lasts until around 6 months of age. If Baby retains the reflex, it can result in problems with his development of fine motor skills, handwriting and self-feeding.
The Step Reflex
Sometimes referred to as the walking or dancing reflex, this one happens while you hold Baby.
Appearance: Hold Baby upright and allow his feet to touch a solid surface. Watch as he takes alternating steps as if walking. An asymmetrical step reflex may indicate a muscle weakness or nerve injury.
Duration: This reflex lasts till about 2 - 3 months of age. But don’t feel bad when it goes away — he will be walking again before you know it.
The Galant Reflex
This reflex prepares Baby for crawling and walking as it helps develop a range of motion in his hips.
Appearance: Hold Baby face down and run your finger down one side of his back, parallel to the spine. Watch as he swings his hips toward the direction of the touch and curves his body in that direction.
Duration: This reflex is present at birth and lasts until 3 - 6 months of age. If he retains the Galant reflex, it can result in fidgeting, an inability to sit still and has even been linked to bed wetting. It can also cause symptoms that overlap with typical ADHD symptoms as mentioned in the Moro reflex.
When to Consult Your Pediatrician
If you notice an absence of one of these reflexes, bring it up with your pediatrician. According to Spanier, the absent reflexes can indicate a nervous system problem such as a brain injury or cerebral palsy.
Also, sometimes Baby’s developing nervous system does not suppress these primitive reflexes and he may retain them. This may indicate nervous system problems, such as cerebral palsy. They can also lead to later problems with learning and development.
Spanier adds that reasons Baby may retain some reflexes include a traumatic birth, head trauma, lack of “tummy time” and excessive time spent in a stroller, car seat or bouncer that restrict his movements.
“It’s important that babies be given lots of opportunities to move and explore their environments,” says Spanier.
If you suspect problems that relate to primitive reflexes your baby retains, an evaluation by an occupational therapist may be beneficial.