Ante- and perinatal factors for cerebral palsy: case-control study in Estonia.

Establishing consistency between cerebral palsy registries in reporting of new cases enables more effective collaboration in terms of researching predisposing factors. To identify antenatal and intrapartum risk factors for cerebral palsy in the Estonian population, we undertook a matched case-control study of 153 children with cerebral palsy, ascertained from a population-based survey. One hundred two maternal, antenatal, and intrapartum variables were initially retrieved from medical records. Main outcome measures were the odds ratio estimates of relative risk of cerebral palsy. As a result of the study, and considering the whole spectrum of severity, the relevant risk factors during pregnancy were bleeding after 20 weeks, anemia in the second half of pregnancy, pregnancy-induced hypertension in the second half of pregnancy, and preeclampsia. The most important intrapartum factors were premature birth, placental abruption, an acute hypoxic event during delivery, and any fetal presentation other than vertex. Predisposing factors related to neonatal condition were an Apgar score < or = 7 at the first and fifth minutes of life, hypoxic-ischemic encephalopathy, and assisted ventilation. Our findings suggest that intrapartum factors, including those hypothetically realized through hypoxic-ischemic pathways, are not of low importance in the etiology of cerebral palsy.