title: Economic modelling of antenatal screening and ultrasound scanning programmes for identification of fetal abnormalities.
abstract: OBJECTIVE
  Within the framework of a health technology assessment and using an economic model, to determine the most clinically and cost effective policy of scanning and screening for fetal abnormalities in early pregnancy.
  
  
  METHODS
  A discrete event simulation model of 50,000 singleton pregnancies.
  
  
  METHODS
  Maternity services in Scotland.
  
  
  METHODS
  Women during the first 24 weeks of their pregnancy.
  
  
  METHODS
  The mathematical model was populated with data on uptake of screening, prevalence, detection and false positive rates for eight fetal abnormalities and with costs for ultrasound scanning and serum screening. Inclusion of abnormalities was based on the relative prevalence and clinical importance of conditions and the availability of data. Six strategies for the identification of abnormalities prenatally including combinations of first and second trimester ultrasound scanning and first and second trimester screening for chromosomal abnormalities were compared.
  
  
  METHODS
  The number of abnormalities detected and missed, the number of iatrogenic losses resulting from invasive tests, the total cost of strategies and the cost per abnormality detected were compared between strategies.
  
  
  RESULTS
  First trimester screening for chromosomal abnormalities costs more than second trimester screening but results in fewer iatrogenic losses. Strategies which include a second trimester ultrasound scan result in more abnormalities being detected and have lower costs per anomaly detected.
  
  
  CONCLUSIONS
  The preferred strategy includes both first and second trimester ultrasound scans and a first trimester screening test for chromosomal abnormalities. It has been recommended that this policy is offered to all women in Scotland.
authors.affiliation: NHS Quality Improvement Scotland, Glasgow, UK.
authors.forename: K
authors.initials: K
authors.lastname: Ritchie
authors.forename: I
authors.initials: I
authors.lastname: Bradbury
authors.forename: J
authors.initials: J
authors.lastname: Slattery
authors.forename: D
authors.initials: D
authors.lastname: Wright
authors.forename: K
authors.initials: K
authors.lastname: Iqbal
authors.forename: G
authors.initials: G
authors.lastname: Penney
mesh_terms: D002869:Chromosome Aberrations; D003362:Cost-Benefit Analysis; D005260:Female; D005333:Fetus / Q000002:abnormalities*; D006801:Humans; D008954:Models, Biological; D010342:Patient Acceptance of Health Care; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis / Q000191:economics*; D012606:Scotland; D016216:Ultrasonography, Prenatal / Q000191:economics