title: First-trimester detection of structural abnormalities and the role of aneuploidy markers.
abstract: OBJECTIVE
  To determine the sensitivity of first-trimester ultrasound for diagnosing different structural anomalies in chromosomally normal pregnancies, and to establish the role of aneuploidy markers in the detection of abnormalities.
  
  
  METHODS
  This was a retrospective study of chromosomally normal singleton pregnancies with an 11-14-week scan performed in our center during 2002-2009. The ultrasound examination included an early fetal anatomy survey and assessment of nuchal translucency, ductus venosus blood flow and nasal bone.
  
  
  RESULTS
  Among 13 723 scanned first-trimester pregnancies with no genetic anomalies and complete follow-up, 439 fetuses (3.2%) were found to present with structural anomalies (194 with major anomalies and 245 with only minor anomalies). Forty-nine per cent of major structural anomalies were detected during the first-trimester scan, the highest rates corresponding to acrania (17/17), holoprosencephaly (three of three), hypoplastic left heart syndrome (10/10), omphalocele (six of six), megacystis (seven of eight) and hydrops (eight of nine). Higher than expected detection rates were obtained for skeletal (69%) and cardiac (57%) defects, coincidentally showing the highest presence of an increased nuchal translucency or abnormal ductus venosus blood flow (38% and 52%, respectively). The finding of an absent nasal bone did not appear to be associated with structural defects.
  
  
  CONCLUSIONS
  About half of major structural abnormalities can be diagnosed in the first trimester. Increased nuchal translucency or abnormal ductus venosus blood flow appear to be associated with cardiac and skeletal defects and may facilitate early detection.
authors.affiliation: Department of Maternal-Fetal Medicine, Institute of Gynecology, Obstetrics and Neonatology, Hospital Clínic Barcelona, Barcelona, Catalonia, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Grande
authors.forename: M
authors.initials: M
authors.lastname: Arigita
authors.forename: V
authors.initials: V
authors.lastname: Borobio
authors.forename: J M
authors.initials: JM
authors.lastname: Jimenez
authors.forename: S
authors.initials: S
authors.lastname: Fernandez
authors.forename: A
authors.initials: A
authors.lastname: Borrell
mesh_terms: D000782:Aneuploidy; D015415:Biomarkers; D001783:Blood Flow Velocity; D005260:Female; D005318:Fetal Heart / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D009295:Nasal Bone / Q000002:abnormalities / Q000000981:diagnostic imaging*; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal
chemical_list: D015415:Biomarkers