The life expectancy of people who have perinatally acquired cerebral palsy can be similar to that of the general population, or it can be reduced substantially. The most important factors that are associated with reduced survival are disabilities of motor, cognitive, or visual functions. Prematurity and low birth weight are associated with lower rates of disability, and better survival. A 2-year-old who has severe cerebral palsy has about a 40% chance of living to age 20, in contrast to a child who has mild cerebral palsy, for whom the chance is 99%. Cerebral palsy, respiratory diseases, epilepsy, and congenital malformation are the most commonly recorded causes of early death.