title: First-trimester screening for Down's syndrome.
authors.forename: Kypros H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D009333:Neck / Q000000981:diagnostic imaging* / Q000196:embryology; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000592:standards*; D014481:United States