In approximately 70 percent of cases, cerebral palsy results from events occurring before birth that can disrupt the normal development of the brain. A small number of children also develop brain injuries in the first months or years of life that can result in cerebral palsy. In many cases, the cause of cerebral palsy in a child is unknown. Some of the causes of cerebral palsy are:

Infections during the pregnancy period:

Certain infections in the mother such as including rubella or German measles, cytomegalovirus or mild viral infection and toxoplasmosis or mild parasitic infection can cause brain damage and result in cerebral palsy. Maternal infections involving the placental membranes may contribute to cerebral palsy in full-term as well as premature babies. Reproductive or urinary tract infections also may increase the risk of premature delivery which is another risk factor for cerebral palsy.

The fetus not receiving sufficient oxygen:

If the placenta is not functioning properly or it tears away from the uterus wall before delivery, the fetus may not receive sufficient oxygen resulting in risk of cerebral palsy.

Premature delivery:

Premature babies who weigh less than 3.33 pounds are up to 30 times more prone to develop cerebral palsy than full-term babies. Many of these premature babies suffer from bleeding in the brain, which can damage delicate brain tissue, or develop periventricular leukomalacia that is destruction of nerves around the fluid-filled cavities or ventricles in the brain.

Asphyxia or lack of oxygen during labor and delivery:

Very few of the type of brain injuries that can result in cerebral palsy are caused by asphyxia.

Diseases of Blood:

Rh disease is an incompatibility between the blood of the mother and her fetus and it can cause severe jaundice and brain damage leading to cerebral palsy. Blood clotting disorders or thrombophilias in either mother or baby also may increase the risk.

Severe jaundice:

Jaundice is caused by the build-up of a pigment called bilirubin in the blood and sometimes it becomes severe. If untreated, severe jaundice can pose a risk of permanent brain damage resulting in athetoid cerebral palsy.

Birth defects:

Babies having brain malformations, various genetic diseases and other physical birth defects have an increased risk of cerebral palsy.

Approximately 10 percent of children with cerebral palsy acquire it after birth due to brain injuries that occur during the first two years of life including brain infections such as meningitis and head injuries.