The term cerebral palsy is used to describe a group of conditions that arise during the first few years of a child's life. These conditions are usually the result of impaired development of, or damage to, the part of the brain that controls movement and posture. This developmental failure or damage results in spastic limb muscles and difficulty crawling, walking and grasping objects. Mental retardation and other symptoms may also be present. Cerebral palsy has no cure at present, and not all the factors that contribute to it are fully understood. However, research has helped explain some of the causes.

If cerebral palsy is present from birth, it is called congenital cerebral palsy. While the cause of congenital cerebral palsy is unknown in most cases, several factors are thought to contribute. Infections during pregnancy, such as rubella (German measles), toxoplasmosis and cytomegalovirus can cause damage to the fetal brain that may result in cerebral palsy. If the blood groups of the mother and fetus are not compatible, the mother's body may produce antibodies that destroy blood cells in the fetus, leading to jaundice. Compounds that are produced during jaundice can cause fetal and infant brain damage. If either the mother or the fetus has a blood clotting disorder, this may lead to bleeding into the fetal brain, and subsequent brain cell damage and cerebral palsy.

During labor and delivery, a severe shortage of oxygen supply to the infant's brain, or asphyxia, can result in brain cell damage. Such damage may lead to cerebral palsy, accompanied in some cases by seizures and mental retardation. Asphyxia only accounts for about six percent of all cerebral palsy cases; most infants with oxygen deprivation during labor and delivery develop normally.

If cerebral palsy develops after birth, it is called acquired cerebral palsy. Common causes of acquired cerebral palsy in infants are brain infections and head trauma.