title: Optic nerve hypoplasia: Risk factors and epidemiology.
abstract: OBJECTIVE
  To study the epidemiology of optic nerve hypoplasia.
  
  
  METHODS
  Children with optic nerve hypoplasia and visual impairment were identified through the Swedish Register of Visually Impaired Children. Pre- and perinatal characteristics were obtained from the Medical Birth Registry and by scrutinizing pregnancy and delivery records. Clinical characteristics of children with optic nerve hypoplasia are described. The following risk factors were studied: maternal age, parity, maternal smoking, gestational duration, birth weight, delivery method, Apgar score, maternal disease during pregnancy, drugs used in early pregnancy.
  
  
  RESULTS
  Young maternal age, first parity, maternal smoking, preterm birth and factors associated with preterm birth were risk factors for optic nerve hypoplasia. There was an indicated association with the use of fertility drugs and antidepressant drugs.
  
  
  CONCLUSIONS
  Optic nerve hypoplasia is apparently associated not only with other anomolies, notably of the central nervous system, but also with signs of general disturbance in fetal development.
authors.affiliation: Department of Ophthalmology, University Hospital of Lund, Lund, Sweden. kristina.tornqvist@oft.lu.se
authors.forename: Kristina
authors.initials: K
authors.lastname: Tornqvist
authors.forename: Anders
authors.initials: A
authors.lastname: Ericsson
authors.forename: Bengt
authors.initials: B
authors.lastname: Källén
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005124:Eye Abnormalities / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008423:Maternal Age; D009900:Optic Nerve / Q000002:abnormalities*; D012042:Registries / Q000706:statistics & numerical data; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D013548:Sweden / Q000453:epidemiology; D014786:Vision Disorders / Q000453:epidemiology*; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*