title: [Ambiguous sex: prevalence at birth in the maternity ward of the clinical hospital of the university of Chile].
abstract: BACKGROUND
  Ambiguous sex has a great phenotypic variability and is a serious medical and social problem.
  
  
  OBJECTIVE
  To study the prevalence of ambiguous sex among newborns.
  
  
  METHODS
  As part of the ECLAMC (Cooperative Latin American Study of Congenital Malformations) all newborns with malformations are registered and the next normal newborn is considered as a control.
  
  
  RESULTS
  50.253 births occurred (between 1982 and 1999) in the University of Chile Maternity Hospital. The rate of congenital malformations was 6.78% and the prevalence of ambiguous sex was 4.7 per 10.000 births. Affected children had a lower birth weight, lower gestational age and a lower maternal age than controls. The most frequent associated malformations were of the urinary (64%) and cardiovascular systems (60.7%). Thirty two percent of affected children had specific syndromes.
  
  
  CONCLUSIONS
  The prevalence of ambiguous sex in this study was 4.7 per 10.000 births, which is higher than that reported in the ECLAMC (1.9 per 10,000).
authors.affiliation: Unidad de Neonatología, Hospital Clínico Universidad de Chile.
authors.forename: M E
authors.initials: ME
authors.lastname: Hubner
authors.forename: J
authors.initials: J
authors.lastname: Nazer
authors.forename: L
authors.initials: L
authors.lastname: Cifuentes
mesh_terms: D016022:Case-Control Studies; D002677:Chile / Q000453:epidemiology; D000013:Congenital Abnormalities / Q000453:epidemiology*; D012734:Disorders of Sex Development / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005313:Fetal Death; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D015995:Prevalence