Research Prospective studies to determine risk factors
across populations are costly and difficult when only two
per thousand of all pregnancies will result in a child with
cerebral palsy. Most research has involved retrospective
studies where obstetric and perinatal histories of groups of
children with cerebral palsy are compared with controls
without cerebral palsy. Attempts are then made to identify
prenatal and perinatal exposures common to children with
cerebral palsy. Natural events have provided evidence of
prenatal determinants of cerebral palsy on rare occasions.