title: Free beta-hCG as first-trimester marker for fetal trisomy.
authors.forename: K
authors.initials: K
authors.lastname: Spencer
authors.forename: J N
authors.initials: JN
authors.lastname: Macri
authors.forename: D A
authors.initials: DA
authors.lastname: Aitken
authors.forename: J M
authors.initials: JM
authors.lastname: Connor
mesh_terms: D006063:Chorionic Gonadotropin / Q000097:blood*; D018997:Chorionic Gonadotropin, beta Subunit, Human; D002887:Chromosomes, Human, Pair 18; D004314:Down Syndrome / Q000175:diagnosis; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D006801:Humans; D010446:Peptide Fragments / Q000097:blood*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis; D014314:Trisomy
chemical_list: D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D010446:Peptide Fragments