title: Sequential pathways of testing after first-trimester screening for trisomy 21.
authors.forename: Fergal D
authors.initials: FD
authors.lastname: Malone
mesh_terms: D000328:Adult; D004314:Down Syndrome / Q000175:diagnosis / Q000235:genetics*; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011266:Pregnancy-Associated Plasma Protein-A / Q000235:genetics*; D011296:Prenatal Diagnosis / Q000379:methods; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D011266:Pregnancy-Associated Plasma Protein-A