title: Cost utility of prenatal diagnosis and the risk-based threshold.
abstract: BACKGROUND
  Prenatal testing guidelines recommend offering amniocentesis or chorionic villus sampling to women aged 35 years or older, or who have been found by screening to be at a similarly high risk of giving birth to an infant with Down's syndrome or another chromosomal abnormality. This threshold was chosen, in part, because 35 was the approximate age at which amniocentesis was cost beneficial when testing guidelines were developed in the USA in the 1970s. We aimed to assess the economic validity of thresholds based on age or risk for offering invasive prenatal diagnosis.
  
  
  METHODS
  We did a cost-utility analysis of chorionic villus sampling and amniocentesis versus no invasive testing using data from randomised trials, case registries, and a utility assessment of 534 diverse pregnant women aged 16-47 years.
  
  
  RESULTS
  In the USA, compared with no diagnostic testing, amniocentesis costs less than US15000 dollars per quality-adjusted life year gained for women of all ages and risk levels. The results do not depend on maternal age or risk of Down's syndrome-affected birth. The cost-utility ratio for any individual woman depends on her preferences for reassurance about the chromosomal status of her fetus, and, to a lesser extent, for miscarriage.
  
  
  CONCLUSIONS
  Prenatal diagnostic testing can be cost effective at any age or risk level. Current guidelines should be changed to offer testing to all pregnant women, not just those whose risk of carrying an affected fetus exceeds a specified threshold.
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, CA, USA.
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Harris
authors.forename: A Eugene
authors.initials: AE
authors.lastname: Washington
authors.forename: Robert F
authors.initials: RF
authors.lastname: Nease
authors.forename: Miriam
authors.initials: M
authors.lastname: Kuppermann
mesh_terms: D000022:Abortion, Spontaneous / Q000191:economics; D000328:Adult; D000649:Amniocentesis / Q000191:economics / Q000592:standards; D015193:Chorionic Villi Sampling / Q000191:economics; D025063:Chromosome Disorders / Q000175:diagnosis*; D003362:Cost-Benefit Analysis; D003365:Costs and Cost Analysis; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000191:economics; D005820:Genetic Testing / Q000191:economics; D017408:Guidelines as Topic / Q000592:standards; D006801:Humans; D007223:Infant; D008423:Maternal Age; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D011296:Prenatal Diagnosis / Q000191:economics* / Q000592:standards; D012307:Risk Factors; D014481:United States