title: Changes in the size of the lateral ventricles in the normal-term newborn following vaginal delivery.
abstract: BACKGROUND
  This is a study of the size of the lateral ventricles in a population of normal-term newborns following vaginal delivery.
  
  
  OBJECTIVE
  To assess the time course for the lateral ventricles to change from closed to open following vaginal delivery.
  
  
  METHODS
  A total of 143 normal-term newborns had a videotaped cranial ultrasound examination during the period from 1 to 156 h after birth. Many had from one to three additional examinations when returning for well-baby checks. Three methods [overlapping intervals (smoothed percentages), life table, and geometric distribution] were used to construct the approximate distributions of completely closed, partially open, and open ventricles.
  
  
  RESULTS
  Using smoothed percentages it was estimated that within 12 h of birth, 80% of newborns had closed lateral ventricles, 19% had partially open ventricles, and only 1% were completely open. The estimated median time from birth to partially open ventricles was in the period 36 to 60 h. The life table gave the estimated median time to partially open ventricles as 74 h. Fitting the data to a geometric distribution gave an estimated mean of 63 h.
  
  
  CONCLUSIONS
  The majority of normal newborns have closed lateral ventricles following vaginal delivery and these are partially opened by day 3 after birth.
authors.affiliation: Department of Radiology, Children's Hospital Los Angeles, 4650 Sunset Boulevard, Los Angeles, CA 90027, USA. mdnelson@chla.usc.edu
authors.forename: Marvin D
authors.initials: MD
authors.lastname: Nelson
authors.forename: C Jane
authors.initials: CJ
authors.lastname: Tavaré
authors.forename: Leonard
authors.initials: L
authors.lastname: Petrus
authors.forename: Paul
authors.initials: P
authors.lastname: Kim
authors.forename: Floyd H
authors.initials: FH
authors.lastname: Gilles
mesh_terms: D002552:Cerebral Ventricles / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology; D036861:Delivery, Obstetric; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D012016:Reference Values; D013997:Time Factors; D014463:Ultrasonography