Cerebral palsy is caused by brain damage .  There are many possible reasons why a child has brain damage. Your doctor must carefully review your child's health history and conduct a variety of medical and neurological tests to help determine the cause.  Cerebral palsy is caused by an injury to the brain before, during, or shortly after birth.  In many cases, no one knows for sure what caused the brain injury or what may have been done to prevent the injury.  A large number of factors which can injure the developing brain may produce cerebral palsy.  In general, however, there are two problems that can cause cerebral palsy:

• failure of the brain to develop properly ( developmental brain malformation )
• neurological damage to the child's developing brain

Whatever the cause of your child's cerebral palsy, the severity of the brain damage generally depends on the type and timing of the injury.  For example, in very premature babies, bleeding into the brain ( intraventricular hemorrhage ) can cause extensive damage.  Also, the longer an unborn child goes without oxygen, the greater the extent of brain tissue damage.

Ten to fifteen percent of cerebral palsy is caused from a recognized brain injury, such as infection (like meningitis), bleeding into the brain, and damage caused by lack of oxygen.  It is very important that you understand that a brain injury caused during delivery in many cases could have been prevented.  Medical mistakes are responsible for thousands and thousands of cerebral palsy cases.  It would be virtually impossible for a parent, on their own, to determine if a medical mistake caused their child's cerebral palsy or brain damage.  It is only through the concerted efforts of a legal/medical team that can answer the question, "was my child's cerebral palsy preventable?"

There may also be a number of risk factors that, though not causes in themselves, increase the chance of cerebral palsy occurring when present. The presence of a risk factor does not mean cerebral palsy will occur, nor does the absence of a risk factor mean that cerebral palsy will not occur.  If a risk factor is present, it should alert parents and health care professionals to be even more observant of the infant's development.  Risk factors can be associated with the parents, as well as the child.  The following are risk factors related to parents that can increase the risk of cerebral palsy:

• Mother 40 years or older
• Mother 20 years or younger
• Father 20 years or younger
• African-American ethnicity.

The following are risk factors related to the child that can increase the risk of cerebral palsy:

• A first child or child born fifth or later in the family
• One of a pair of twins, especially if one twin dies
• Low birth weight, less than 3.5 pounds
• Premature infant, less than 37 weeks.

The following are other known risk factors that can increase the risk of cerebral palsy:

• Rh or ABO blood type incompatibility between mother and infant
• Infection of the mother with German measles or other virus in early pregnancy
• Attack by micro-organisms on the central nervous system of the infant.

More than one risk factor can be present at the same time, such as low birth weight and being a twin.  Such combinations can further increase the risk of cerebral palsy occurring.