title: Trends in the prevalence of cerebral palsy among very preterm infants (<31 weeks' gestational age).
abstract: BACKGROUND
  The birth prevalence of cerebral palsy varies over time among very preterm infants, and the reasons are poorly understood.
  
  
  OBJECTIVE
  To describe the variation in the prevalence of cerebral palsy among very preterm infants over time, and to relate these differences to other maternal or neonatal factors.
  
  
  METHODS
  A population-based cohort of very preterm infants was evaluated over a 20-year period (1988 to 2007) divided into four equal epochs.
  
  
  RESULTS
  The prevalence of cerebral palsy peaked in the third epoch (1998 to 2002) while mortality rate peaked in the second epoch (1993 to 1997). Maternal anemia, tocolytic use and neonatal need for home oxygen were highest in the third epoch.
  
  
  CONCLUSIONS
  Lower mortality rates did not correlate well with the prevalence of cerebral palsy. Maternal risk factors, anemia and tocolytic use, and the newborn need for home oxygen were highest during the same epoch as the peak prevalence of cerebral palsy.
authors.affiliation: The Perinatal Follow-Up Program, IWK Health Centre; ; Department of Pediatrics; Dalhousie University, Halifax, Nova Scotia ; Department of Obstetrics and Gynaecology; Dalhousie University, Halifax, Nova Scotia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Vincer
authors.affiliation: Department of Pediatrics; Dalhousie University, Halifax, Nova Scotia ; Department of Obstetrics and Gynaecology; Dalhousie University, Halifax, Nova Scotia ; The Perinatal Epidemiology Research Unit, Dalhousie University, Halifax, Nova Scotia.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Allen
authors.affiliation: Department of Obstetrics and Gynaecology; Dalhousie University, Halifax, Nova Scotia.
authors.forename: Victoria M
authors.initials: VM
authors.lastname: Allen
authors.affiliation: Department of Obstetrics and Gynaecology; Dalhousie University, Halifax, Nova Scotia.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Baskett
authors.affiliation: Department of Pediatrics; Dalhousie University, Halifax, Nova Scotia ; Department of Obstetrics and Gynaecology; Dalhousie University, Halifax, Nova Scotia ; The Perinatal Epidemiology Research Unit, Dalhousie University, Halifax, Nova Scotia.
authors.forename: Colleen M
authors.initials: CM
authors.lastname: O'Connell
keywords: Cerebral palsy; Infant; Population-based; Premature