Current research suggests that perinatal asphyxia accounts
for between 6% and 8% of cerebral palsy .
However, even in this group, there may be other underlying
causes making infants at risk for perinatal asphyxia and, in
most children, prevention is not possible. Prenatal events are
thought to be responsible for approximately 75% of all
cases of cerebral palsy although it is usually impossible to
determine the nature and the exact timing of the damaging
event. Estimates of the proportion of cases with postnatal
acquired cerebral palsy range between 10%
assume a prenatal cause in the absence of clear evidence
for a perinatal or postnatal cause .