title: Screening for chromosomal defects.
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D004314:Down Syndrome / Q000000981:diagnostic imaging; D005260:Female; D005865:Gestational Age; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D008423:Maternal Age; D009295:Nasal Bone / Q000196:embryology; D009333:Neck / Q000000981:diagnostic imaging / Q000196:embryology; D010641:Phenotype; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis; D012307:Risk Factors; D014314:Trisomy / Q000175:diagnosis*; D016216:Ultrasonography, Prenatal / Q000379:methods*
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A