title: Optic nerve hypoplasia in North America: a re-appraisal of perinatal risk factors.
abstract: OBJECTIVE
  The purpose of this study is to describe and clarify the birth and prenatal characteristics of a large cohort of children with optic nerve hypoplasia.
  
  
  METHODS
  This is a descriptive report of 204 patients aged </= 36 months and enrolled in a prospective study at the Children's Hospital Los Angeles. Birth characteristics, including complications, were abstracted from study files and medical records. Systematic maternal interviews were conducted to obtain detailed prenatal histories. National birth data were used for comparison with birth findings.
  
  
  RESULTS
  Birth characteristics were unremarkable for birthweight and gestation, but significant for increased frequency of caesarean delivery and fetal and neonatal complications. Young maternal age and primaparity were dominating maternal features. Preterm labour, gestational vaginal bleeding, low maternal weight gain and weight loss during pregnancy were prevalent.
  
  
  CONCLUSIONS
  These findings confirm young maternal age and primaparity as associated risk factors, challenge many other suggested factors such as alcohol and drug abuse, and introduce potentially significant prenatal characteristics such as maternal weight loss and early gestational vaginal bleeding as aetiological correlates.
authors.affiliation: The Vision Center at Childrens Hospital Los Angeles, and Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California 90027, USA. pgarciafilion@chla.usc.edu
authors.forename: Pamela
authors.initials: P
authors.lastname: Garcia-Filion
authors.forename: Cassandra
authors.initials: C
authors.lastname: Fink
authors.forename: Mitchell E
authors.initials: ME
authors.lastname: Geffner
authors.forename: Mark
authors.initials: M
authors.lastname: Borchert
mesh_terms: D001724:Birth Weight; D002675:Child, Preschool; D005124:Eye Abnormalities / Q000453:epidemiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008423:Maternal Age; D009656:North America / Q000453:epidemiology; D009900:Optic Nerve / Q000002:abnormalities*; D010298:Parity; D011247:Pregnancy; D011446:Prospective Studies; D012042:Registries / Q000706:statistics & numerical data; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology