health answers:
We do not know the cause of most cases of cerebral palsy. That is, we are unable to determine what caused cerebral palsy in most children who have congenital CP. We do know that the child who is at highest risk for developing CP is the premature, very small baby who does not cry in the first five minutes after delivery, who needs to be on a ventilator for over four weeks, and who has bleeding in his brain. Babies who have congenital malformations in systems such as the heart, kidneys, or spine are also more likely to develop CP, probably because they also have malformations in the brain. Seizures in a newborn also increase the risk of CP. There is no combination of factors which always results in an abnormally functioning individual. That is, even the small premature infant has a better than 90 percent chance of not having cerebral palsy. There are a surprising number of babies who have very stormy courses in the newborn period and go on to do very well. In contrast, some infants who have rather benign beginnings are eventually found to have severe mental retardation or learning disabilities. Http://gait.aidi.udel.edu/res695/homepage/pd_ortho/clinics/c_palsy/cpweb.htm
The disorders are caused by faulty development of or damage to motor areas in the brain that disrupts the brain’s ability to control movement and posture. Http://www.ninds.nih.gov/disorders/cerebral_palsy/cerebral_palsy.htm
Cerebral palsy results from damage to certain parts of the developing brain.
This damage can occur early in pregnancy when the brain is just starting to form, during the birth process as the child passes through the birth canal, or after birth in the first few years of life.
In many cases, the exact cause of the brain damage is never known.
At one time, problems during birth, usually inadequate oxygen, were blamed for cerebral palsy.
We now know that fewer than 10% of cases of cerebral palsy begin during birth (perinatal).
In fact, current thinking is that at least 70-80% of cases of cerebral palsy begin before birth (prenatal).
Some cases begin after birth (postnatal).
In all likelihood, many cases of cerebral palsy are a result of a combination of prenatal, perinatal, and postnatal factors.
Risk factors linked with cerebral palsy include the following:
Infection, seizure disorder, thyroid disorder, and/or other medical problems in the mother
Birth defects, especially those affecting the brain, spinal cord, head, face, lungs, or metabolism
Rh factor incompatibility, a difference in the blood between mother and fetus that can cause brain damage in the fetus (Fortunately, this is almost always detected and treated in women who receive proper prenatal medical care.)
Certain hereditary and genetic conditions
Complications during labor and delivery
Premature birth
Low birth weight (especially if less than 2 pounds at birth)
Severe jaundice after birth
Multiple births (twins, triplets)
Lack of oxygen (hypoxia) reaching the brain before, during, or after birth
Brain damage early in life, due to infection (such as meningitis), head injury, lack of oxygen, or bleeding
http://www.emedicinehealth.com/articles/32062-2.asp