Beyond missed milestones, what are the main categories of early CP signs?

Four main categories, often appearing together rather than alone: muscle tone that's noticeably too stiff or too loose, primitive newborn reflexes that persist beyond the age they should normally fade, feeding difficulties such as a poor suck or trouble coordinating swallowing, and unusual, persistent postures or asymmetric movement.

What is the ATNR, and why does the specific way it presents matter so much?

The asymmetric tonic neck reflex is a newborn reflex where turning a baby's head to one side extends the arm on that same side while the opposite arm bends, sometimes called the fencing posture. It typically fades by around 4 to 6 months. The genuinely important distinction is whether a baby can break out of this position with active effort. A typically developing baby resists it and works to return to a neutral position. A baby who cannot escape the posture despite clearly trying and even crying for 30 seconds or more is showing a more concerning, obligatory version of the reflex.

By what ages should the main primitive reflexes normally disappear?

The Moro, or startle, reflex and the tonic labyrinthine reflex typically fade by 4 to 6 months. The palmar grasp reflex typically fades by 5 to 6 months. The asymmetric and symmetric tonic neck reflexes typically fade by 6 to 7 months. These are general guides rather than exact cutoffs, since healthy infants show real variation in timing.

Can feeding difficulties really be an early sign of cerebral palsy?

Yes, genuinely. Because the same nervous system pathways affecting body movement also affect the muscles used for sucking and swallowing, a poor or uncoordinated suck, difficulty managing the pace of feeding, or noticeable trouble coordinating sucking, swallowing, and breathing together can be an early, sometimes overlooked, sign worth mentioning to your paediatrician.

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Q: What reflex pattern is specifically associated with spastic cerebral palsy?

A combination is more meaningful than any single reflex alone: a retained asymmetric tonic neck reflex, a persistent palmar grasp reflex, an obligatory Moro reflex, and a persistent Babinski sign beyond 24 months, typically alongside increased muscle tone and exaggerated reflexes overall. It's specifically the combination and persistence pattern that matters, not one isolated finding.

Q: How much should I trust a single sign I've noticed in isolation?

With real caution. Healthy infants vary enormously in muscle tone, spontaneous movement, and exactly when primitive reflexes fade, which makes any single observation, on its own, genuinely hard to interpret with confidence. What matters more is a pattern across more than one category, tone plus reflexes plus feeding, for example, and how that pattern changes or persists over time, rather than one isolated sign viewed alone.

Missed milestones are only part of the picture. Muscle tone, newborn reflexes that linger past when they should fade, feeding, and posture all matter just as much, and are far less often explained clearly. This is that fuller picture, organized simply and honestly.

Written by CP Clinic Medical Team Tovmed Medical Center, Vinnytsia, Ukraine

Medically reviewed by Prof. Vigein Tovmasian PhD · Orthopedic Surgeon · Honorary Doctor of Ukraine

The four categories that actually matter

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Muscle tone

Noticeably too stiff or too loose, not just occasionally but as a consistent pattern.

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Primitive reflexes

Newborn reflexes that persist well beyond the age they should typically fade.

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Feeding

A poor or uncoordinated suck, or difficulty managing sucking, swallowing, and breathing together.

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Posture and movement

Unusual, persistent positions, or noticeable asymmetry between the two sides of the body.

Missed motor milestones themselves, sitting, crawling, walking, are covered in full depth in our dedicated age-by-age milestone guide. This article focuses specifically on the other signs that often appear alongside, or even before, a missed milestone.

Muscle tone: what “stiff” or “floppy” means

Doctors often assess tone using specific, gentle techniques: the pull-to-sit manoeuvre, gently pulling a baby up from lying to sitting by the hands and watching how much the head lags behind, and vertical suspension, holding a baby upright under the arms and observing how the body and legs respond. Both have genuine predictive value throughout infancy, which is exactly why your pediatrician performs them, even briefly, at routine visits.

You don’t need to perform these yourself, but understanding what they’re checking for demystifies a routine exam that can otherwise feel mysterious or rushed.

Primitive reflexes and when they should fade

Moro (startle) reflex

Fades by 4–6 months

Sudden head movement causes the arms to extend, spread, then draw back in. Persistence beyond this window is worth mentioning.

Palmar grasp reflex

Fades by 5–6 months

Fingers automatically close tightly around anything pressed into the palm. Should ease as voluntary, purposeful grasping develops.

Asymmetric tonic neck reflex (ATNR)

Fades by 4–6 months

Turning the head to one side extends the arm on that side while the opposite arm bends, sometimes called the fencing posture. Covered in full detail just below, since exactly how it presents matters enormously.

Tonic labyrinthine reflex

Fades by 4–6 months

Affects overall body tone based on head position relative to gravity.

The single most important distinction: obligatory vs transient

This changes everything about how to read the ATNR

A typically developing baby who briefly shows the fencing posture will resist it and actively work to return to a neutral position.

A baby who cannot escape the posture despite clearly trying, and even crying, for 30 seconds or more is showing a genuinely different, more concerning, “obligatory” version of the same reflex.

This single distinction, transient versus obligatory, is exactly the kind of specific, practical detail that turns a vague worry into something concrete and worth describing precisely to your pediatrician.

The pattern specifically linked to spastic CP

A retained ATNR, a persistent palmar grasp, an obligatory Moro reflex, and a persistent Babinski sign beyond 24 months, typically alongside increased muscle tone and exaggerated reflexes overall. It’s the combination and the persistence together that matters, not any single finding alone.

Feeding as an early, overlooked sign

The same nervous system pathways controlling body movement also control the muscles used for sucking and swallowing. A poor or uncoordinated suck, difficulty managing the pace of a feed, or noticeable trouble coordinating sucking, swallowing, and breathing together can be a genuinely early sign, and one that’s easy to overlook or attribute to something else entirely.

One honest caution before you read further

Worth holding onto throughout

Healthy infants vary enormously in muscle tone, spontaneous movement, and exactly when primitive reflexes fade. Any single observation, on its own, is genuinely hard to interpret with confidence. What matters far more is a pattern across more than one category, tone plus reflexes plus feeding, for example, and how that pattern holds or changes over time. And even then, some children with mild cerebral palsy show only very subtle signs at this early age, which is exactly why our General Movement Assessment guide and guide to recognising asymmetry exist as further, more specific tools.

If any of this genuinely concerns you, our guide to advocating for earlier assessment covers exactly what to ask for and how to raise it effectively.

Noticed a pattern of signs in your own child?

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Frequently asked questions

Beyond missed milestones, what are the main early sign categories?

Muscle tone that’s noticeably too stiff or loose, primitive reflexes persisting past when they should fade, feeding difficulties, and unusual, persistent posture or asymmetric movement.

What is the ATNR, and why does how it presents matter?

A newborn reflex causing a “fencing posture” when the head turns, fading by 4-6 months. Whether a baby can break out of the posture with effort matters enormously: typical babies resist and escape it; an inability to escape despite trying is more concerning.

By what ages should primitive reflexes disappear?

Moro and tonic labyrinthine reflexes by 4-6 months, palmar grasp by 5-6 months, tonic neck reflexes by 6-7 months. General guides, not exact cutoffs, given real variation.

What reflex pattern is linked to spastic CP specifically?

Retained ATNR, persistent palmar grasp, obligatory Moro, and persistent Babinski beyond 24 months, alongside increased tone and exaggerated reflexes. The combination matters, not one isolated finding.

Can feeding difficulties really be an early CP sign?

Yes. The same pathways affecting movement affect sucking and swallowing muscles, so a poor suck or trouble coordinating sucking, swallowing, and breathing can be an early, overlooked sign.

How much should I trust one sign I’ve noticed alone?

With real caution. Normal variation is huge, so a single observation is hard to interpret confidently. Patterns across categories, and how they change over time, matter far more.

References

“Primitive Reflexes: Comprehensive Neurological Assessment Across the Lifespan.” StatPearls, NCBI Bookshelf. NCBI ↗
“Cerebral Palsy Clinical Presentation.” Medscape. Medscape ↗
Zafeiriou DI. “Primitive reflexes and postural reactions in the neurodevelopmental examination.” Pediatric Neurology, 2004. Pediatric Neurology ↗
Hamer EG, et al. “Prognostic significance of neurological signs in high-risk infants – a systematic review.” Developmental Medicine & Child Neurology, 2016. Wiley ↗
“Diagnosing cerebral palsy—the earlier the better.” Contemporary Pediatrics. Contemporary Pediatrics ↗

Medical disclaimer: This article is for informational purposes. Assessment of tone, reflexes, and overall development should be carried out directly by your pediatrician or a qualified specialist.