Nested Case control study of preterm infants (< 31 weeks gestational age) with Cerebral Palsy from a defined geographic region in Canada † 1358

Between June 1, 1984 and Dec 31, 1994, all 654 live born infants < 31 weeks gestational age whose mothers resided in a defined geographic region(all of Nova Scotia except Cumberland county and the 4 counties in Cape Breton) were enrolled Perinatal Follow-Up Program of Nova Scotia (PFUP). 529(81%) survived, 508 (96%) were followed and 51 of these 508 surviving infants were identified with cerebral palsy. The 51 infants with cerebral palsy were matched with 51 case control infants (of the 508 survivors) who were free of cerebral palsy for the following characteristics: 1) sex, 2) gestational age within 1 week and 3) date of birth within 2 years. All infants in the study were examined by a neonatologist or house staff under the supervision of a neonatologist by 18 months corrected gestational age. Neurologic disorders such as intraventricular haemorrhage (IVH), cystic periventricular leukomalacia (PVL), hydrocephalus requiring a shunt and neonatal seizures were very predictive of CP while hyperkalemia and hyperbilirubinemia were less predictive of cerebral palsy. Antenatal administration of magnesium sulfate failed to achieve statistical significance in protecting the newborn from cerebral palsy; however, the sample size was small. Stepwise logistic regression model revealed only 3 variables significantly predictive of cerebral palsy, cerebral ultrasound abnormality, either grade 4 IVH or cystic PVL, (cummulative R² = 0.22, p < 0.001), peak unconjugated bilirubin(cummulative R² = 0.31, p = 0.001) and serum potassium ≥ 7 Meq/L(cummulative R² = 0.34, p = 0.02). Table

Table 1 TABLE: Group characteristics