In the vast majority of cases, yes. Between 85% and 90% of cerebral palsy cases are classified as congenital, meaning the brain injury or abnormal development that causes it happens before or during birth. The remaining 10% to 15% of cases are acquired after birth, typically from an infection, oxygen loss, or head injury during the first two years of life. So while cerebral palsy is almost always rooted in something that happens around the time of birth, it is not exclusively a condition people are born with.
What “Congenital” Cerebral Palsy Means
Congenital cerebral palsy results from brain damage or abnormal brain development that occurs while the baby is still in the womb or during delivery. This doesn’t mean the condition is genetic in the way eye color is inherited, though certain gene mutations can play a role by affecting how the brain forms. More often, the causes involve problems with blood flow or oxygen to the developing brain, infections the mother experiences during pregnancy, or complications during labor.
When researchers examine brain scans of children with cerebral palsy, the most common finding is damage to the brain’s white matter, the tissue that carries signals between different brain regions. A large European study of over 350 children with CP found white matter damage in about 43% of cases. Other patterns included damage to structures deep in the brain (about 13%), damage to the outer brain surface (9%), and structural malformations that formed during development (9%). Only about 12% of children with CP had brain scans that appeared completely normal.
How Birth Complications Factor In
One of the most discussed birth-related causes is birth asphyxia, which happens when blood flow to the placenta is interrupted and the baby’s brain is deprived of oxygen. If this oxygen loss lasts long enough, it can cause permanent neurological injury. The exact contribution of birth asphyxia to cerebral palsy is debated. Some research puts it at less than 10% of all CP cases, while other studies suggest it accounts for more than 30%. The wide range reflects differences in how researchers define and measure oxygen deprivation at birth.
What’s clear is that most congenital cerebral palsy traces back to events during pregnancy rather than the delivery itself. Problems with brain development, prenatal infections, and disruptions to blood supply in the womb account for the largest share of cases.
Premature Birth and Low Birth Weight
Being born early is one of the strongest risk factors for cerebral palsy. Babies born very prematurely have brains that are still in critical stages of development, making them more vulnerable to injury. Among the smallest premature infants, those weighing less than about 2.2 pounds (1,000 grams) at birth, roughly 10% will eventually be diagnosed with cerebral palsy. The overall global prevalence of CP is about 1.5 per 1,000 live births in high-income countries, so the risk for extremely premature babies is dramatically higher than average.
In low- and middle-income countries, CP rates are significantly higher, reaching about 3.4 per 1,000 live births. This gap largely reflects differences in access to prenatal care, neonatal intensive care, and interventions that protect premature babies’ brains.
When Cerebral Palsy Happens After Birth
Acquired (or postneonatal) cerebral palsy accounts for that remaining 10% to 15% of cases. To qualify as CP, the brain injury must occur before age 2. After that cutoff, brain damage from an injury or illness is generally classified differently, even if it produces similar movement difficulties.
The most common postnatal causes include infections like meningitis, near-drowning incidents, cardiac arrest, severe jaundice that goes untreated, and traumatic head injuries. Among these, oxygen deprivation events like near-drowning tend to produce the most severe functional limitations. Children with CP from these causes often have damage to the brain’s gray matter, which controls movement and sensation more directly.
The good news is that rates of postnatal CP have been declining in high-income countries. Infant vaccination programs have reduced brain infections, and public safety measures like pool fencing legislation and water safety campaigns have lowered drowning-related brain injuries in young children.
Prevention Before and During Birth
One of the most evidence-backed preventive measures involves giving magnesium sulfate to mothers at risk of delivering before 34 weeks. A major analysis of five clinical trials covering over 6,000 infants found that this treatment reduced the risk of cerebral palsy by about 32%. The number needed to treat was 41, meaning that for every 41 women who receive the treatment, one case of CP or infant death is prevented. International guidelines now recommend it as standard care for early preterm births.
Beyond that, good prenatal care, management of maternal infections, and advances in neonatal intensive care have all contributed to a gradual decline in CP prevalence in wealthier countries over recent decades.
When Cerebral Palsy Gets Diagnosed
Even though CP originates before or shortly after birth, it often isn’t diagnosed right away. Historically, the average diagnosis has come between 12 and 24 months of age in high-income countries, and even later elsewhere. In Bangladesh, for example, the average age at diagnosis has been around 5 years.
Recent clinical guidelines push for earlier detection, aiming for a reliable diagnosis between 3 and 12 months. For babies under 5 months, doctors use a specific movement assessment that analyzes the quality of an infant’s spontaneous movements, combined with brain imaging and a neurological exam. For babies older than 5 months, standardized motor assessments replace the movement analysis, since the specific movement patterns evaluated are no longer present at that age. In clinics following these newer guidelines, CP is being confirmed at an average of about 8.5 months, with suspicion raised as early as 4 months.
Early signs that prompt evaluation include unusual movement patterns in newborns, hand dominance appearing before 4 months (healthy babies don’t show a strong hand preference that early), and not sitting independently by 9 months. A brain MRI showing specific injury patterns, combined with these motor signs, is typically enough to confirm the diagnosis.