When Cerebral Palsy Symptoms Show Up After Birth and What Parents Notice First

Cerebral palsy symptoms typically appear between birth and 18 months of age, with most parents first noticing concerns about muscle tone (stiffness or floppiness), missed motor milestones, or asymmetric movement during the first 3 to 6 months. Even though 85 to 90 percent of cerebral palsy cases are congenital (meaning the underlying brain injury occurred before or during birth), most children are not formally diagnosed until age 2 or later per the National Institute of Child Health and Human Development. The gap between when parents first notice something and when a formal diagnosis is made matters because earlier intervention produces better outcomes. Knowing what to look for, when to look for it, and when to escalate concerns can shorten that gap meaningfully.

This article walks through what parents typically notice at each stage of the first two years, what those observations may mean, and what to do when concerns arise.

Why Cerebral Palsy Symptoms Are Usually Noticed After Birth, Not at Birth

Cerebral palsy is fundamentally a disorder of motor control, and motor control develops over months and years rather than appearing fully formed at birth. A newborn’s nervous system is still maturing, and the patterns of movement that distinguish cerebral palsy from typical development emerge gradually as the baby starts to do more. This is why even severe forms of cerebral palsy may not be obvious immediately after delivery, and milder forms may not become apparent until a child starts walking.

A few factors shape when symptoms become noticeable:

• The severity of the underlying brain injury. More severe injuries tend to produce earlier and more obvious signs. Milder injuries may not be apparent until subtle motor or coordination differences emerge during preschool years.
• The type of cerebral palsy. Spastic cerebral palsy, the most common form, often becomes noticeable as muscle stiffness develops over the first several months. Dyskinetic and ataxic forms may take longer to become apparent because the relevant movement patterns develop later.
• Whether the baby was born premature or with risk factors. Babies who were premature, had low birth weight, spent time in the NICU, or experienced birth complications such as oxygen deprivation are typically monitored more closely. These babies may have a diagnosis suspected and confirmed earlier than babies whose risk factors were not identified at birth.
• The infant’s individual developmental pace. Healthy babies vary considerably in when they reach motor milestones, which means that some delays that turn out to indicate cerebral palsy initially look like normal variation.

The reality that diagnosis often takes time can be frustrating for families, but advances in screening and assessment over the past decade have made it possible to identify high-risk infants much earlier than was historically the case. NYBI maintains a more detailed page on the cerebral palsy diagnosis process for families who want to understand what specialists look for.

What Parents Typically Notice in the First 1 to 3 Months

The earliest signs of cerebral palsy in newborns are abnormal muscle tone (the baby feels unusually stiff or unusually floppy), persistent head lag when picked up, and arching of the back and neck during handling. These signs reflect how the baby feels physically rather than what the baby does, since babies under 3 months have not yet developed the motor skills that reveal later signs.

The NICHD and NINDS group early signs into broad categories of “younger than 6 months,” but parents often notice specific patterns much earlier, particularly in the first few weeks. The observations below combine the early-period signs documented by NICHD and NINDS with additional clinical findings supported by the pediatric neurology literature.

The most common early observations include:

• The baby feels unusually stiff or unusually floppy. This is one of the most commonly reported early signs and is documented by both NICHD and NINDS. A baby with abnormal muscle tone may feel rigid when held (hypertonia) or limp like a rag doll (hypotonia). Both extremes can be early indicators of cerebral palsy or other neurological concerns.
• Significant head lag when picked up. When a young baby is gently pulled from lying flat to a sitting position, NINDS notes that an inability to bring the head along with the body is a recognized early sign of cerebral palsy. Some head lag is normal in the first weeks but should improve steadily.
• Arching the back and neck unusually when held. NICHD specifically notes that some infants with cerebral palsy “may overextend their back and neck, constantly acting as though they are pushing away from you.” While occasional arching is normal, persistent and pronounced arching can indicate abnormal muscle tone.
• Legs that get stiff or cross when picked up. NICHD lists this as a classic sign in babies younger than 6 months.
• A weak or asymmetric Moro reflex (startle reflex). The Moro reflex is the typical newborn response of throwing both arms out and bringing them back together when startled. According to StatPearls, an asymmetric Moro reflex at birth can be indicative of neuronal damage, brachial plexus injury, or clavicular fracture, and prolonged retention of the reflex past 6 months can be a sign of spastic cerebral palsy.
• Difficulty with feeding and excessive drooling. Oral motor coordination challenges are documented by NINDS as a feature of cerebral palsy and can manifest in early infancy as poor latch, slow feeding, or persistent drooling. These signs are nonspecific and have many possible causes, but they are worth tracking when they occur alongside other concerns.
• Persistent “cortical thumbs” past 4 months. Thumb-in-palm posture and fisting are normal findings in newborns, but their persistence beyond 4 months of age, or a tightly fisted hand that does not open spontaneously, may be a sign of upper motor neuron injury, according to a Journal of Pediatrics clinical observation.
• A high-pitched, unusual cry. A distinctive high-pitched newborn cry has been recognized since the 1960s as a clinical sign associated with birth asphyxia and neurological injury, most commonly observed in the immediate newborn period rather than as a sole sign of cerebral palsy.

It is important to keep these observations in context. Many babies show one or more of these signs occasionally without having cerebral palsy. The pattern that prompts evaluation is generally a combination of signs, persistence over time, and parental instinct that something is not right.

What Parents Notice from 3 to 6 Months

Between 3 and 6 months, the most diagnostically important signs of cerebral palsy are delayed head control, hands that stay fisted past 4 months, asymmetric movement (using one side of the body more than the other), and difficulty bringing hands to midline. This is when motor delays become more visible and when many parents first raise concerns with their pediatrician.

Common observations during this period:

• Delays in head control. By 3 to 4 months, most babies can hold their head up steadily during tummy time and when held upright. A baby who still cannot do this consistently by 4 to 5 months warrants attention.
• Difficulty rolling over. Most babies begin rolling from front to back around 4 months and from back to front by 6 months. Significant delays, or rolling that consistently happens to only one side, can be a concerning pattern.
• Hands that stay fisted. Babies typically open their hands and begin reaching by 3 to 4 months. A baby whose hands remain consistently closed in fists past this age, or whose fingers grip a placed object weakly or not at all, may have motor concerns.
• Asymmetric movement. This is one of the most diagnostically important observations. A baby who consistently uses one side of the body more than the other (reaching with only one hand while the other stays curled, kicking with one leg more than the other) raises specific concern for hemiplegic cerebral palsy. True handedness does not normally develop until at least 12 to 18 months, so early one-sidedness is not normal.
• Stiffness during diaper changes or dressing. Parents often notice that the baby’s legs feel hard to separate during diaper changes, or that one or both arms are stiff when getting dressed. This stiffness, if persistent, may reflect spasticity.
• The baby does not bring hands to midline. By around 3 to 4 months, babies typically begin bringing both hands together at the center of the body, looking at them, and using them together. A baby who does not do this consistently may have motor planning or muscle control challenges.

Importantly, this is also the developmental window when international guidelines recommend formal screening for cerebral palsy in high-risk infants. The General Movements Assessment, a standardized observation tool used between 3 and 5 months, is highly predictive of cerebral palsy. Combined with neonatal MRI and the Hammersmith Infant Neurological Examination, the 2017 international guidelines published by Novak et al. in JAMA Pediatrics support diagnosing cerebral palsy as early as 3 to 6 months in some cases. A subsequent multi-site implementation study published in Pediatrics in 2020 demonstrated that consistent application of these guidelines reduced the average age at diagnosis from 19.5 months to 9.5 months. Specialists at major developmental clinics across New York, including the Weinberg Family Cerebral Palsy Center at NewYork-Presbyterian, Mount Sinai, and NYU Langone, use these tools as part of standard care for high-risk infants.

What Parents Notice from 6 to 12 Months

By 6 to 12 months, the most concerning signs of cerebral palsy are inability to sit independently by 9 months, no attempts at crawling or unusual crawling patterns (such as army crawling or asymmetric crawling), poor weight bearing through the legs, and persistent primitive reflexes that should have integrated by this age. Missed motor milestones in this window are harder to dismiss and often prompt formal evaluation.

What parents commonly notice:

• The baby is not sitting independently by around 9 months. Most babies sit without support by 6 to 8 months. A baby who still cannot do this by 9 to 10 months has a significant developmental delay that warrants evaluation.
• No attempts at crawling, or unusual crawling patterns. Crawling typically begins between 7 and 10 months. Babies with cerebral palsy may not crawl, may crawl in unusual patterns (such as army crawling without alternating hands and legs), or may “bunny hop” without using both legs symmetrically. A child who pushes off with one hand and one leg while dragging the other side is showing a pattern strongly associated with hemiplegic cerebral palsy.
• Poor weight bearing through the legs. When held standing, most babies begin to put weight through their legs by 6 to 9 months. A baby who consistently goes limp at the legs or, conversely, holds the legs rigidly straight when placed on a surface, may have abnormal lower extremity tone.
• Persistent primitive reflexes. Reflexes such as the Moro reflex and the asymmetric tonic neck reflex are normal in newborns but typically integrate (disappear) by 4 to 6 months. Persistence of these reflexes past their normal window can be a sign of neurological immaturity associated with cerebral palsy.
• Continued strong asymmetry. Hand preference at this age, or continued strong asymmetry in arm or leg use, becomes increasingly significant as the baby’s overall motor capacity grows.
• Difficulty bringing hands to mouth. By 6 to 9 months, most babies can readily bring hands and objects to the mouth. Persistent difficulty with this can indicate motor coordination challenges.

The American Academy of Pediatrics recommends formal developmental screening at the 9-month well-child visit, which is one of the most important opportunities to identify motor delays. Pediatricians use standardized screening tools to assess whether a baby is meeting expected milestones, and concerns identified at this visit typically lead to referral for further evaluation.

What Parents Notice from 12 to 24 Months

Between 12 and 24 months, the most common signs of cerebral palsy are significant delay in walking (no independent steps by 18 months), unusual gait patterns (toe-walking, scissoring gait, dragging one leg), frequent falls beyond age-typical norms, and clear hand preference before 18 months. Children with milder forms of cerebral palsy who did not raise concerns earlier often become apparent during this window as walking and complex movements develop.

Observations during this period include:

• Significant delay in walking. Most children take their first independent steps between 9 and 18 months, with the average around 12 to 14 months. A child who is not walking by 18 months should have a developmental evaluation.
• Unusual gait patterns. Children with cerebral palsy may walk on their toes, walk with a “scissoring” gait where the knees cross inward, drag one leg, or walk with one foot turned in or out. These patterns may be subtle initially but become more apparent over time.
• Frequent falls or poor balance. Children with ataxic cerebral palsy or mild spastic forms may walk but show persistent unsteadiness, frequent falls beyond what is typical for the age, or difficulty with transitions like sitting down or standing up.
• Asymmetric use of hands during play. A clear preference for one hand by 12 to 18 months, especially when accompanied by reduced or awkward use of the other hand, is a strong indicator that warrants evaluation.
• Difficulty with self-care milestones. Activities like holding a cup, finger feeding, picking up small objects with a pincer grasp, or beginning to undress can be delayed or difficult.
• Speech and feeding differences. Some children with cerebral palsy have associated oral motor difficulties that affect both speech development and feeding. Persistent drooling past age 2, difficulty chewing solids, or significant speech delay can all be relevant observations.
• Stiffness or unusual posture during sleep. Some parents notice that their child’s body remains tense or in an unusual posture even during sleep, which can reflect underlying tone abnormalities.

The AAP also recommends formal developmental screening at the 18-month well-child visit, with autism-specific screening added at 18 and 24 months. By this point, families with concerns have usually had multiple conversations with pediatricians and may have already been referred to a developmental pediatrician, pediatric neurologist, or multidisciplinary team.

The “Wait and See” Trap

One of the most common experiences described by families of children with cerebral palsy is being told to “wait and see” when concerns were first raised. While well-intentioned, this advice can delay access to early intervention services that are most effective during the first two years of life. Brain plasticity is greatest in the early years, and therapeutic interventions started in infancy generally produce better functional outcomes than the same interventions started later.

Several practical principles help families navigate this tension:

• Trust your instincts. Parents are with their baby every day and often notice subtle differences before clinicians do. If something feels off, that observation is worth taking seriously even if it cannot be precisely articulated.
• Document specific observations. Brief notes about when a baby is not doing something expected (or doing something unusual) become valuable evidence during clinical evaluations. Video recordings on a phone can be particularly useful for capturing patterns that may not be visible during a brief office visit.
• Ask for a referral, not just reassurance. If a pediatrician suggests waiting, families can request referral to a pediatric neurologist or developmental pediatrician for evaluation. Early specialist evaluation does not commit the family to a diagnosis; it ensures the right people are watching if concerns continue.
• Use the New York Early Intervention Program. New York operates the Early Intervention Program (EIP) under Article 25 of Public Health Law for children under 3 with diagnosed conditions or developmental delays. EIP eligibility does not require a confirmed diagnosis. Families can self-refer by calling the Growing Up Healthy Hotline at 1-800-522-5006, or by calling 311 in New York City. Therapy services are provided at no out-of-pocket cost.
• Get a second opinion if needed. If a family’s concerns are not being addressed, seeking evaluation at a multidisciplinary developmental clinic is reasonable. Major NY centers serving children with motor concerns include the Weinberg Family Cerebral Palsy Center at NewYork-Presbyterian, Mount Sinai’s Pediatric Movement Disorders Program, and NYU Langone’s pediatric neurology services.

What to Do When You Have Concerns About Your Baby’s Development

The path from “I think something might be off” to “we have a clear plan” usually involves several steps, and knowing what to expect helps families move through them efficiently.

The typical sequence:

1. Document your observations. Write down what you have noticed and when it started. Include video recordings of specific concerns when possible.
2. Raise concerns with the pediatrician at the next well-child visit, or sooner. Be specific. Rather than “I’m worried about her development,” try “She’s not yet rolling over and her left arm seems to move differently than her right.”
3. Request developmental screening if it has not been done. Standardized tools like the Ages and Stages Questionnaire give an objective measure of developmental progress.
4. Ask for referral to specialist evaluation if concerns persist. Pediatric neurologists, developmental pediatricians, and pediatric physical or occupational therapists can provide more detailed assessment than a general pediatric visit allows.
5. Refer to Early Intervention. EIP referral can happen in parallel with diagnostic evaluation. Therapy services do not have to wait for a confirmed diagnosis.
6. Consider neuroimaging if recommended. MRI is the most useful imaging study for cerebral palsy and can identify underlying brain injury or malformation. The decision to image is typically made by the specialist team based on clinical findings.

Some children evaluated through this process turn out not to have cerebral palsy, and that is genuinely reassuring news that comes from a thorough evaluation rather than from waiting. Others receive an early diagnosis and gain access to therapies during the most important window of brain development. Either outcome is better than continued uncertainty.

For families whose child’s cerebral palsy may have been caused by a preventable birth complication, NYBI also maintains information on the legal framework for New York birth injury claims, including the 10-year filing deadline under CPLR § 208 for medical malpractice cases involving children. This is a separate consideration from the medical workup but is worth understanding because the timeline for legal action runs concurrently with the timeline for early intervention.

Frequently Asked Questions

At what age can cerebral palsy be diagnosed?

Cerebral palsy can be diagnosed as early as 3 to 6 months of age in high-risk infants using a combination of neonatal MRI, the General Movements Assessment, and the Hammersmith Infant Neurological Examination. Most diagnoses have historically been made between 12 and 24 months, but international guidelines published in 2017 support much earlier diagnosis when the right tools are used. Mild forms of cerebral palsy may not be diagnosed until age 2 or later, when more complex motor and coordination differences become apparent. Diagnosis timing depends on severity, the presence of identified risk factors, and the family’s access to specialist evaluation.

What is usually the first sign parents notice?

The first signs noticed by parents are usually about how the baby feels physically (unusually stiff or floppy) or how the baby moves (asymmetric movements, head lag, persistent fisting of the hands). Many parents describe an instinctive sense that something is not right before they can articulate exactly what is different. Trusting that instinct and bringing specific observations to the pediatrician is the appropriate first step.

Can mild cerebral palsy be missed in the first year?

Yes. Children with mild cerebral palsy, particularly mild hemiplegic or diplegic forms, may not have obvious symptoms in the first year and may be diagnosed only when they begin walking and show subtle differences in gait, coordination, or hand use. Some mild cases are not formally diagnosed until preschool or school age. This is one reason continued developmental monitoring through age 3 and beyond is important even for children whose first year appeared typical.

What is the difference between developmental delay and cerebral palsy?

Developmental delay refers to a child not reaching milestones at the expected times, but the term itself does not specify a cause. Cerebral palsy is a specific neurological diagnosis defined by permanent, non-progressive motor impairment caused by brain injury or abnormal brain development. Many children with delays do not have cerebral palsy, and the diagnostic process distinguishes between the two through clinical examination, imaging, and observation over time. NYBI maintains a page on cerebral palsy misdiagnosis for families exploring whether a different diagnosis may better explain their child’s presentation.

Should I push for an MRI if my pediatrician says to wait?

A direct MRI request is generally not the right next step, but a referral to a pediatric neurologist or developmental pediatrician is. The typical evaluation sequence is clinical screening, specialist evaluation, and then imaging if the clinical picture suggests it. The specialist can determine whether MRI is warranted based on direct evaluation. MRI in young infants typically requires sedation, which is one reason it is not done routinely without clinical indication. If a family is being told to wait and feels strongly that something is wrong, the specialist referral is the productive escalation.

What Families Should Know About Recognizing Cerebral Palsy

Cerebral palsy is one of the most common motor disabilities in childhood, but it presents differently in every child. The patterns described in this article are typical, not universal, and a child’s actual presentation may not follow any predictable script. What is consistent is that early recognition leads to earlier access to therapies, and earlier therapies generally produce better functional outcomes.

A few principles cut across the entire timeline. Parents who track milestones and bring specific observations to clinical visits get more useful answers than parents who arrive with general worries. Pediatricians who take parental concerns seriously and refer for evaluation when warranted serve children better than those who default to “wait and see.” And families who connect with the Early Intervention Program and specialist developmental services early, even before a formal diagnosis is made, position their child to benefit from the most plastic period of brain development.

Whether a child ultimately receives a cerebral palsy diagnosis or a different one, the discipline of careful observation and informed advocacy benefits the child either way. There is no clinical downside to seeking evaluation when concerns arise, and there is significant developmental upside to acting early when those concerns turn out to matter.

Quick Reference of Red Flags by Age

The following summary consolidates the developmental signs discussed throughout this article into a quick-reference format families can use during pediatric visits or share with caregivers.

Birth to 3 months:

• Persistent stiffness or floppiness when held
• Significant head lag when picked up from lying flat
• Arching of the back and neck during handling
• Legs that consistently stiffen or cross when picked up
• Asymmetric Moro reflex (markedly weaker on one side)

3 to 6 months:

• Hands that remain fisted past 4 months (cortical thumb posture)
• Cannot hold head up steadily by 4 months
• Does not bring hands to midline
• Uses one side of the body more than the other
• Does not roll over by 6 months

6 to 12 months:

• Cannot sit independently by 9 months
• Does not crawl, or crawls in asymmetric or “army crawl” patterns
• Cannot bear weight on legs when held standing
• Persistent primitive reflexes (Moro, ATNR) past 6 months
• Strong hand preference (which is not normal at this age)

12 to 24 months:

• Not walking by 18 months
• Toe-walking, scissoring gait, or dragging one leg
• Frequent falls beyond what is age-typical
• Clear hand preference before 18 months
• Persistent drooling past age 2 or significant speech delay

If a child shows multiple signs in any age category, or any single sign that persists despite the typical developmental window passing, evaluation by a pediatrician (and referral to a pediatric neurologist or developmental pediatrician if concerns persist) is appropriate.

This article is for educational purposes only and does not constitute medical or legal advice. Decisions about your child’s evaluation and care should be made in consultation with qualified pediatric specialists. For legal questions related to a birth injury, consult a qualified New York attorney.