Most parents witness the Moro reflex in the first 48 hours: lay the baby down too fast and the arms throw out wide, eyes go big, and they cry. It looks like fear. It isn't — it's a brainstem-driven response that all healthy term newborns share, and one of the simplest neurological screens we have. Knowing the main reflexes, what triggers them, and what counts as a normal versus a worrying pattern, helps you recognise what's already being checked at the NIPE and 6–8-week reviews. Healthbooq covers what newborns do reflexively and what those movements actually mean.
What "Primitive" Means Here
Primitive reflexes come from the brainstem and spinal cord — the older, deeper parts of the nervous system that are functional well before birth. They don't require the cortex, which is the part doing the slow work of building voluntary movement, attention, and (eventually) speech.
Reflexes serve three rough purposes:
- Feeding — rooting and sucking direct the baby toward the breast or bottle and coordinate the suck-swallow-breathe sequence
- Protection — the Moro and the blink reflex respond to sudden change or threat
- Motor scaffolding — grasp, stepping, and the ATNR provide pre-wired patterns that the cortex will later override with voluntary control
When the cortex develops normally, it inhibits these reflexes. They don't vanish — they become inaccessible as automatic responses. If the cortex is damaged or develops atypically (cerebral palsy, hypoxic injury, some genetic conditions), reflexes can persist or re-emerge later in life.
What's Normal — And What Each One Tells You
The Moro reflex. Triggered by a sudden change in head position, a loud sound, or the feeling of falling. The baby's arms abduct (fling out), fingers spread, and then the arms come back to the midline, often with a cry. Present from birth in healthy term infants and integrated by 4–6 months.
- Normal: a vigorous, symmetric response in the first weeks; gradually weaker over the first few months.
- Concerning: absent at birth (suggests CNS depression — possibly maternal sedation, hypoxic injury, or significant prematurity); asymmetric (one arm responding less — assess for clavicle fracture, Erb's palsy / brachial plexus injury, or hemiparesis); still strong past 6 months.
Rooting. Stroke the cheek or corner of the mouth and the baby turns toward the stimulus and opens their mouth. Present from birth; integrates by 3–4 months as voluntary head control takes over.
- Normal: clear turning toward the stimulus; useful when establishing breastfeeding latch.
- Concerning: absent or weak rooting in a term newborn, especially if paired with feeding difficulty.
Sucking. Present from around 32 weeks gestation. A finger placed gently on the palate triggers a rhythmic, vigorous suck. Integrates around 3–4 months as feeding becomes more voluntary.
- Normal: strong, coordinated suck with a clear seal.
- Concerning: weak, disorganised, or uncoordinated suck; difficulty pacing the suck-swallow-breathe sequence; tiring quickly at the breast or bottle. These can reflect prematurity, hypotonia, tongue-tie (ankyloglossia), or neurological difficulty and warrant midwife or feeding-support review.
Palmar grasp. Press into the palm and the fingers close around your finger tightly enough that some newborns can briefly support a portion of their body weight (which you don't test deliberately). Present from birth; integrates by 4–6 months.
- Normal: strong, sustained grip; releases when the palm is no longer stimulated.
- Concerning: persistently absent at birth, marked asymmetry, or persistence well past 6 months — the latter is associated with later difficulty developing a pincer grip and fine motor control.
Plantar grasp. Press the ball of the foot and the toes curl downward. Present from birth; integrates around 9–12 months as the foot starts to flatten for weight-bearing.
Babinski. Stroke the outer edge of the sole from heel toward the toes; the big toe extends upward and the smaller toes fan out. In a baby, this is normal and remains so until about 12–18 months. In an older child or adult, the same response is abnormal and indicates upper motor neuron pathology — but in a 6-month-old, it's expected and not a cause for concern.
Stepping (walking) reflex. Hold the baby upright with feet touching a flat surface and they make alternating stepping movements. Disappears by around 2 months, re-emerging much later as voluntary walking. This is unrelated to when a child will actually walk and there is no value in trying to "exercise" it.
Asymmetric tonic neck reflex (ATNR / fencer posture). Turn the head to one side and the arm and leg on that side extend; the opposite arm flexes. Present from birth, expected to integrate by 4–6 months.
- Concerning: persistence past 6 months can interfere with rolling, midline reaching, and later bilateral skills like crawling, reading, and writing.
What the NIPE Actually Tests
The Newborn and Infant Physical Examination is performed within 72 hours of birth and repeated at 6–8 weeks. The reflex and neurological component looks for:
- Presence of the Moro, palmar grasp, rooting, suck, and plantar response
- Symmetry — both sides of the body responding the same way
- Tone — neither floppy (hypotonia) nor stiff (hypertonia)
- Absent abnormal movements — no jitteriness disproportionate to the situation, no seizure-like activity
If the examiner finds something they want to follow up — an absent Moro, an asymmetric grasp, low tone — they will say so and arrange the appropriate next step. Most apparent abnormalities at the first exam either resolve or have benign explanations (a sleepy baby gives a less impressive Moro, for example), and the 6–8-week review provides a second look.
When to Raise It Yourself
You don't need to formally test reflexes at home, but flag the following at your next health visitor or GP appointment, or sooner if marked:
- One side of the body consistently moving less than the other
- A baby who's noticeably floppy, stiff, or hard to rouse
- A weak, uncoordinated suck affecting feeding
- A reflex (especially the Moro or the ATNR) that's still strong months after the integration window
- Sudden re-emergence of a reflex that had previously disappeared
Most concerns turn out to be benign or transient. The ones that aren't are easier to address early.
Key Takeaways
Newborn reflexes are involuntary responses generated by the brainstem and spinal cord, present from birth in healthy term infants. They are not just curiosities — they are part of the standard neurological screen at the first newborn examination (NIPE) within 72 hours and again at the 6–8-week GP review. A reflex that is absent, weak, or asymmetric in the early days, or that persists strongly months after it should have integrated, is a clue that something in the nervous system needs a closer look. The Moro, rooting, sucking, and palmar grasp reflexes are the ones parents will see most often and the ones examiners pay closest attention to.
