title: First-trimester biochemical screening for Down syndrome.
abstract: Of all markers evaluated for first-trimester biochemical screening for Down syndrome (DS), PAPP-A and free beta-hCG emerged as the most predictive. The combined test uses these markers in conjunction with nuchal translucency measurements, and is estimated to achieve a DS detection rate of 80% to 85% at a 5% false-positive rate. The integrated test, combining first-trimester sonographic and biochemical markers with second-trimester markers, provides a single estimate of a patients DS risk, and may yield a DS detection rate of 94% at a 5% false-positive rate. The acceptability and feasibility of this test, however, remain to be proved.
authors.affiliation: Prenatal Diagnosis Unit, Genetic Institute and Department of Obstetrics and Gynecology, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel. yyaron@post.tau.ac.il
authors.forename: Y
authors.initials: Y
authors.lastname: Yaron
authors.forename: R
authors.initials: R
authors.lastname: Mashiach
mesh_terms: D015415:Biomarkers / Q000097:blood*; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007265:Inhibins / Q000097:blood; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis; D016216:Ultrasonography, Prenatal; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D000509:alpha-Fetoproteins; D007265:Inhibins; D011266:Pregnancy-Associated Plasma Protein-A