title: Second-trimester biochemical screening.
abstract: The past years have seen considerable progress in the area of biochemical screening. Increasing data have now clearly shown the advantages of multiple markers, particularly beta-hCG over AFP alone. There continues to be considerable controversy over the best mathematic algorithm and which markers are best (e.g., beta-HCG, uE3, and so forth). There seems to be a plateau of detection frequencies at about 65% to 70% with current methodologies. Further work needs to be done, however, including some new approaches, if there is to be substantial improvement of screening sensitivity. The combination of biochemical with biophysical parameters as discussed elsewhere in this issue represents the next level of sophistication in the attempt to identify the highest proportion of abnormalities with the fewest false-positives.
authors.affiliation: Department of Obstetrics and Gynecology and Fetal Therapy Program, MCP Hahnemann University School of Medicine, Philadelphia, Pennsylvania, USA.
authors.forename: M I
authors.initials: MI
authors.lastname: Evans
authors.forename: J E
authors.initials: JE
authors.lastname: O'Brien
authors.forename: E
authors.initials: E
authors.lastname: Dvorin
authors.forename: H
authors.initials: H
authors.lastname: Harrison
authors.forename: T H
authors.initials: TH
authors.lastname: Bui
mesh_terms: D000465:Algorithms; D015415:Biomarkers / Q000097:blood; D025063:Chromosome Disorders / Q000097:blood*; D004992:Ethics, Medical; D005260:Female; D006801:Humans; D009436:Neural Tube Defects / Q000097:blood*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis / Q000379:methods*; D011640:Public Policy; D018570:Risk Assessment
chemical_list: D015415:Biomarkers