title: Antenatal screening policies for Down's syndrome. Audit of Down's syndrome screening is not valid.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Wald
authors.forename: Wayne
authors.initials: W
authors.lastname: Huttly
authors.forename: Allan K
authors.initials: AK
authors.lastname: Hackshaw
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008423:Maternal Age; D008485:Medical Audit; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers