If your first child is born at full-term with cerebral palsy, how likely are your future children to be affected?

Depends: CP is generally attributed to an unexplained injury to the developing brain anytime from pregnancy up to the third birthday. The incidence is quoted as 5/1000 and is considered a sporadic event. Statistically you would multiply the incidence # by itself to give predicted recurrence at 2.5/100, 000. A consultation with a geneticist may shed light on any issue from which you have added risks.

Not clear cut: It really depends on the cause. Often there is some identifiable risk factor or cause. For example the child who needs resuscitation at birth or had complicated pregnancy or delivery is more at risk and may not affect your risk of future affected children. But if the child has it as a result of a genetic disorder or a condition in the mom it could put you at risk of recurrence.