Nursing care
Newborn Reflexes, explained for the bedside and the exam
Written and reviewed by Dana Whitfield, RN, MSN · 6 min read · Updated September 2026
Short answer
Newborn reflexes are automatic, involuntary responses present at birth that reflect an intact central nervous system, including Moro, rooting, sucking, palmar and plantar grasp, Babinski, and stepping. Each has an expected window of disappearance in infancy; a reflex that persists past its normal age is the finding that signals a neurological problem, not the reflex itself.
What the concept actually says
Newborn reflexes are primitive, involuntary motor responses to specific stimuli, present from birth and mediated by the brainstem and spinal cord rather than the still-immature cortex. The Moro reflex, the startle response to a sudden loss of support or loud noise, shows symmetric arm extension and abduction followed by flexion, and is normally present from birth and fades by around 4 to 6 months.
Rooting and sucking both support feeding: stroke the cheek near the mouth and the infant turns toward the stimulus and opens the mouth (rooting), and anything placed in the mouth triggers a coordinated suck (sucking). Palmar grasp closes the fingers around an object placed in the palm; plantar grasp curls the toes when the sole is stroked near the base of the toes. Babinski shows fanning of the toes and dorsiflexion of the great toe when the sole is stroked from heel to toe, a finding that would be abnormal in an adult but is expected in infancy. Stepping produces alternating leg movements resembling walking when the infant is held upright with feet touching a flat surface.
The clinical reasoning behind it
The reasoning is straightforward once stated: these reflexes exist because the newborn's cortex has not yet matured enough to inhibit brainstem-level responses. As the cortex develops over the first months of life, it suppresses these primitive reflexes, and each one disappears on its own predictable timeline. Presence at birth, followed by disappearance on schedule, is the pattern that confirms normal neurological maturation.
That framing flips how you interpret an abnormal finding. It is rarely the reflex being present at birth that worries a nurse; it is a reflex being absent, asymmetric, or weak at birth (suggesting a birth injury, such as brachial plexus injury affecting an asymmetric Moro), or a reflex persisting well past its expected window in later infancy (suggesting a central nervous system abnormality, since cortical maturation should have suppressed it by then). Both directions, present when it should have faded, or absent when it should be there, point toward the nervous system as the site of concern.
Applying it under time pressure
In a real assessment or a fast-moving exam question, anchor to two things: is the reflex present at the expected age, and is it symmetric. An asymmetric Moro in a newborn is one of the higher-yield findings tested because it points specifically toward a clavicle fracture or brachial plexus injury on the weaker side, and it is something you can identify in seconds during a routine exam.
For timing questions, don't try to memorize every reflex's exact fade date under pressure; know the general rule instead. Rooting and sucking support early feeding and fade as voluntary feeding control develops, typically by 3 to 4 months. Palmar grasp fades by around 5 to 6 months, and plantar grasp somewhat later. Babinski can normally persist longer in infancy, up to around 12 months to 2 years in some references, before the adult pattern of toe flexion takes over. Stepping fades by around 2 months. When a question describes a reflex clearly past these general windows, the answer is usually pointing at a neurological finding, not a normal variant.
Common misconceptions
The most common misconception is treating the Babinski response as automatically abnormal because it is a red flag in adults. In a newborn or young infant, upgoing toes on plantar stimulation are expected; the same finding in a toddler well past the expected window, or in an adult, is what points to upper motor neuron pathology.
A second misconception is assuming an absent reflex always means neurological damage. A weak or diminished reflex can also reflect a sedated infant, prematurity, or simple timing of the exam relative to feeding or sleep state; context matters before jumping to pathology. A third misconception is testing reflexes in isolation from the rest of the neuro exam. A single equivocal reflex finding is far less meaningful than a pattern across multiple reflexes plus tone, symmetry, and overall behavioral state.
Practice scenarios
Scenario one: a term newborn shows a Moro reflex with full arm extension on the left but minimal movement on the right. This asymmetry, not the presence of the Moro itself, is the finding to report, and it should prompt assessment for clavicle fracture or brachial plexus injury on the right side.
Scenario two: an 8-month-old still shows a strong palmar grasp reflex that should have integrated by around 5 to 6 months. Persistence well past the expected window at this age is a cue to evaluate further for a central nervous system abnormality rather than assume normal variation.
Scenario three: a nurse strokes the sole of a 2-week-old's foot and documents fanning toes with dorsiflexion of the great toe as an abnormal finding requiring escalation. This is the wrong call — Babinski is expected in a healthy newborn at this age, and documenting it as pathological reflects the common misconception, not an actual concern.
Key takeaways
Know the six core reflexes, Moro, rooting, sucking, grasp, Babinski, and stepping, as present-at-birth findings tied to brainstem and spinal function rather than cortical control. Each has an expected window in which it should fade as the cortex matures.
The neurologically significant finding is timing and symmetry, not presence at birth. A reflex missing or asymmetric when it should be there, or lingering well past when it should have disappeared, is what should prompt further neurological evaluation. Build assessment habits around checking symmetry every time and knowing the general fade windows well enough to spot an outlier without needing to recall an exact week.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our maternity and newborn practice questions are the closest set to what this page covers.
Common questions
What does an asymmetric Moro reflex mean in a newborn?
An asymmetric Moro, where one arm extends and abducts fully while the other moves minimally, suggests a possible clavicle fracture or brachial plexus injury on the weaker side. It should be reported and followed up with a focused assessment of that limb.
Is the Babinski reflex normal in newborns?
Yes. Fanning of the toes with dorsiflexion of the great toe on plantar stimulation is an expected finding in newborns and young infants, unlike in older children and adults where it signals upper motor neuron dysfunction. It can normally persist for up to a couple of years before the adult pattern appears.
When should the rooting and sucking reflexes disappear?
Both typically fade by around 3 to 4 months of age as voluntary feeding control develops. Persistence beyond this window, or absence at birth, both warrant further neurological evaluation.
What is more concerning, a reflex that is absent or one that persists too long?
Both directions matter. Absence or asymmetry at birth can point to a birth injury such as brachial plexus injury, while persistence well past the expected fading window in later infancy points toward a central nervous system abnormality, since cortical maturation should have suppressed the reflex by then.
Why do newborns have these reflexes at all?
The newborn cortex has not yet matured enough to inhibit brainstem and spinal-level responses, so primitive reflexes like Moro, rooting, and grasp appear automatically. As the cortex develops over the following months, it suppresses these responses on a predictable schedule.