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.