title: First trimester prenatal diagnosis.
abstract: OBJECTIVE
  The recent developments in first trimester sonography promise to greatly enhance our diagnostic capabilities for detection of aneuploidies. Collateral benefits of nuchal translucency measurements include the prediction of non-chromosomal adverse outcomes. These advances will fundamentally change clinical practices. All obstetricians must therefore have a working knowledge of the expanding literature in this field.
  
  
  RESULTS
  The review covers developments in nuchal translucency based first trimester detection of chromosomal anomalies and discusses the recent literature on the use of fetal nasal bone measurements to further improve diagnostic accuracy. Emerging data on the relationship between nuchal fluid measurement and the risk of cardiac anomaly will also be presented.
  
  
  CONCLUSIONS
  It is likely that the emphasis in obstetric clinical care will shift substantially towards the first trimester. With the enhanced diagnostic capabilities, greater research emphasis will inevitably need to be placed on the first trimester treatment of fetal disorders.
authors.affiliation: University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0526, USA. ray.bahado-singh@ucmail.uc.edu
authors.forename: Ray O
authors.initials: RO
authors.lastname: Bahado-Singh
authors.forename: Chen S Chee
authors.initials: CS
authors.lastname: Cheng
mesh_terms: D000782:Aneuploidy; D002869:Chromosome Aberrations / Q000196:embryology; D003362:Cost-Benefit Analysis; D004314:Down Syndrome / Q000175:diagnosis / Q000196:embryology / Q000235:genetics; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000196:embryology / Q000235:genetics; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000196:embryology / Q000235:genetics; D006801:Humans; D008403:Mass Screening; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000191:economics / Q000941:ethics; D016216:Ultrasonography, Prenatal / Q000191:economics / Q000941:ethics