title: Hemodynamic and antecedent risk factors of early and late periventricular/intraventricular hemorrhage in premature infants.
abstract: OBJECTIVE
  To determine hemodynamic and antecedent risk factors for early and late periventricular/intraventricular hemorrhage (P/IVH) in premature infants.
  
  
  METHODS
  Two prospective cohort studies of 126 (1995-1996) and 128 (1998-1999) infants born <30 weeks' gestation. Head ultrasounds were performed at <6 hours of age, and at 7 and 28 days of age. P/IVH was classified as early (present on initial scan) and late (developed subsequently). Echocardiographic measurement of the superior vena cava (SVC) flow was performed at <6, 10, and 24 hours of age.
  
  
  RESULTS
  Infants with early P/IVH were significantly more likely to be born by vaginal delivery in both cohorts (1995-1996 adjusted odds ratios [OR]: 13.29; 1998-1999 adjusted OR: 18.15). An association with a 1-minute Apgar < or =4 was only significant in the 1998-1999 cohort (adjusted OR: 9.14). Low SVC flow was the only independent risk factor for late P/IVH in both cohorts (1995-1996 adjusted OR: 20.39; 1998-1999 adjusted OR: 5.16). Adjusted for perinatal risk factors, low SVC flow was associated with lower gestation and higher average mean airway pressure in both cohorts, and with a large diameter ductus diameter only in the 1995-1996 cohort.
  
  
  CONCLUSIONS
  Early and late P/IVH have distinct and different risk factors. Early P/IVH is associated with vaginal delivery and possibly low Apgar scores. Late P/IVH is associated with antecedent low SVC flow in the first day.
authors.affiliation: Royal Prince Alfred Hospital Sydney, Sydney, NSW, Australia. david.osborn@email.cs.nsw.gov.au
authors.forename: David A
authors.initials: DA
authors.lastname: Osborn
authors.forename: Nick
authors.initials: N
authors.lastname: Evans
authors.forename: Martin
authors.initials: M
authors.lastname: Kluckow
mesh_terms: D017668:Age of Onset; D001034:Apgar Score; D001783:Blood Flow Velocity; D002543:Cerebral Hemorrhage / Q000453:epidemiology*; D002552:Cerebral Ventricles / Q000098:blood supply*; D015331:Cohort Studies; D015897:Comorbidity; D036861:Delivery, Obstetric; D004452:Echocardiography; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000453:epidemiology; D007234:Infant, Premature; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data; D008297:Male; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D014683:Vena Cava, Superior / Q000000981:diagnostic imaging / Q000503:physiopathology