title: Age-specific variation in aneuploidy incidence among biochemical screening programs.
abstract: OBJECTIVE
  Our purpose was to compare the observed age-related incidence of Down syndrome in two large screening programs with the commonly quoted incidences used in biochemical screening programs.
  
  
  METHODS
  Data from two large prenatal screening programs were stratified in 5-year age groups. The age-related incidence of Down syndrome was compared with the commonly used incidence as reported by Cuckle.
  
  
  RESULTS
  No significant differences were found in age-related incidences of Down syndrome in any age group between the screening groups or among women ages 15 through 29 in any of the three groups. However, for women 30 to 34 and > or = 40 years old, a trend was noted toward a higher incidence in the screening groups. For women ages 35 to 39, the observed incidence was significantly greater in the screening groups compared with the data of Cuckle.
  
  
  CONCLUSIONS
  Our data suggest an underascertainment in Down syndrome risk built into the Cuckle model, particularly in high-risk patients.
authors.affiliation: Department of Obstetrics and Gynecology, Center for Molecular Medicine and Genetics, Wayne State University, Detroit, Michigan, USA.
authors.forename: A I
authors.initials: AI
authors.lastname: Sokol
authors.forename: R L
authors.initials: RL
authors.lastname: Kramer
authors.forename: Y
authors.initials: Y
authors.lastname: Yaron
authors.forename: J E
authors.initials: JE
authors.lastname: O'Brien
authors.forename: F
authors.initials: F
authors.lastname: Muller
authors.forename: M P
authors.initials: MP
authors.lastname: Johnson
authors.forename: M I
authors.initials: MI
authors.lastname: Evans
mesh_terms: D000293:Adolescent; D000328:Adult; D000782:Aneuploidy; D004314:Down Syndrome / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D012307:Risk Factors