title: First-trimester Down syndrome screening.
authors.forename: Terrence W
authors.initials: TW
authors.lastname: Hallahan
authors.forename: David A
authors.initials: DA
authors.lastname: Krantz
authors.forename: V James
authors.initials: VJ
authors.lastname: Macri
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Shine
mesh_terms: D006063:Chorionic Gonadotropin / Q000097:blood*; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D006031:Glycosylation; D006801:Humans; D008403:Mass Screening / Q000379:methods; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis; D014327:Trophoblasts / Q000378:metabolism*
chemical_list: D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; C024889:glycosylated HCG; D011266:Pregnancy-Associated Plasma Protein-A