title: Prenatal risk factors for severe retinopathy of prematurity among very preterm infants of the Australian and New Zealand Neonatal Network.
abstract: OBJECTIVE
  To identify prenatal and perinatal risk factors for clinically severe (stage 3 or 4) retinopathy of prematurity (ROP).
  
  
  METHODS
  Data were collected prospectively as part of the ongoing Australian and New Zealand Neonatal Network audit of high-risk infants (birth weight of <1500 g or gestational age [GA] of <32 weeks) admitted to a level III neonatal unit in Australia or New Zealand. Prenatal and perinatal factors to 1 minute of age were examined for the subset of infants with GA of <29 weeks who survived to 36 weeks' postmenstrual age and were examined for ROP (n = 2105). The factors significantly associated with stage 3 or 4 ROP were entered into a multivariate logistic regression model.
  
  
  RESULTS
  Two-hundred three infants (9.6%) had stage 3 or more ROP. Prematurity was the dominant risk factor, with infants with GA of <25 weeks having 20 times greater odds of severe ROP than infants with GA of 28 weeks. Birth weight for GA also had a "dose-response" effect; the more growth-restricted infants had greater risk, with infants below the 3rd percentile of weight for GA having 4 times greater odds of severe ROP than those between the 25th and 75th percentiles. Male gender was also a significant risk factor (odds ratio: 1.73; 95% confidence interval: 1.25-2.40).
  
  
  CONCLUSIONS
  These data, for a large, essentially population-based cohort, suggest that factors related to the degree of immaturity, intrauterine growth restriction, and male gender contribute to severe ROP.
authors.affiliation: Department of Paediatrics, Christchurch School of Medicine and Health Sciences, PO Box 4345, Christchurch, New Zealand. brian.darlow@chmeds.ac.nz
authors.forename: Brian A
authors.initials: BA
authors.lastname: Darlow
authors.forename: Jolie L
authors.initials: JL
authors.lastname: Hutchinson
authors.forename: David J
authors.initials: DJ
authors.lastname: Henderson-Smart
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Donoghue
authors.forename: Judy M
authors.initials: JM
authors.lastname: Simpson
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Evans
mesh_terms: D001315:Australia; D001724:Birth Weight; D015331:Cohort Studies; D005317:Fetal Growth Retardation / Q000150:complications; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D019102:Infant, Very Low Birth Weight; D009520:New Zealand; D012372:ROC Curve; D012178:Retinopathy of Prematurity / Q000209:etiology*; D012307:Risk Factors