In the industrialized world, the incidence of cerebral palsy is about 2 per 1000 live births.[75] The incidence is higher in males than in females; the Surveillance of Cerebral Palsy in Europe (SCPE) reports a M:F ratio of 1.33:1.[76] Variances in reported rates of incidence across different geographical areas in industrialised countries are thought to be caused primarily by discrepancies in the criteria used for inclusion and exclusion. When such discrepancies are taken into account in comparing two or more registers of patients with cerebral palsy (for example, the extent to which children with mild cerebral palsy are included), the incidence rates converge toward the average rate of 2:1000.

In the United States, approximately 10,000 infants and babies are diagnosed with CP each year, and 1200–1500 are diagnosed at preschool age.[77]

Overall, advances in care of pregnant mothers and their babies has not resulted in a noticeable decrease in CP. This is generally attributed to medical advances in areas related to the care of premature babies (which results in a greater survival rate). Only the introduction of quality medical care to locations with less-than-adequate medical care has shown any decreases. The incidence of CP increases with premature or very low-weight babies regardless of the quality of care.[citation needed]

Prevalence of cerebral palsy is best calculated around the school entry age of about six years, the prevalence in the U.S. is estimated to be 2.4 out of 1000 children[78]

The SCPE reported the following incidence of comorbidities in children with CP (the data are from 1980–1990 and included over 4,500 children over age 4 whose CP was acquired during the prenatal or neonatal period):

• Mental disadvantage (IQ < 50): 31%
• Active seizures: 21%
• Mental disadvantage (IQ < 50) and not walking: 20%
• Blindness: 11% [76]

The SCPE noted that the incidence of comorbidities is difficult to measure accurately, particularly across centers. For example, the actual rate of an intellectual impairment may be difficult to determine, as the physical and communicational limitations of people with CP would likely lower their scores on an IQ test if they were not given a correctly modified version.

Apgar scores have sometimes been used as one factor to predict whether or not an individual will develop CP.[79]