title: Validation of risk estimation using the quadruple test in prenatal screening for Down syndrome.
authors.forename: N J
authors.initials: NJ
authors.lastname: Wald
authors.forename: W J
authors.initials: WJ
authors.lastname: Huttly
mesh_terms: D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012306:Risk