title: Aberrant right subclavian artery in Down syndrome fetuses.
abstract: OBJECTIVE
  The aim of this study is to determine the frequency of aberrant right subclavian artery (ARSA) in trisomic and normal fetuses during the routine detailed ultrasonography in the second trimester and to evaluate the potential value of ARSA as an ultrasonographic marker for trisomy 21.
  
  
  METHODS
  The presence of normal brachicephalic trunk/or ARSA was confirmed in all pregnant women undergoing second trimester detailed fetal anomaly screening beyond 16th week of pregnancy. Amniocentesis following genetic councelling was recommended to all women having either any positive ultrasonographic marker including ARSA or a positive biochemical screening test (triple test) result.
  
  
  RESULTS
  During the 17-month period, 2081 patients were screened, and 23 patients with ARSA (1,1%) and 20 patients with trisomy 21 were detected. Of those 20 patients with trisomy 21, ARSA was detected in seven (%35). On the other hand, 30.4% of the fetuses with ARSA had also trisomy 21. The positive and negative likelihood ratios of ARSA for trisomy 21 were 45.08 and 0.65, respectively.
  
  
  CONCLUSIONS
  In our study, the ARSA in combination with other ultrasound signs increased the risk for trisomy 21 by factor of 45, but the independent ability of ARSA as an isolated marker to predict fetal Trisomy 21 is unclear.
authors: Suleymaniye Maternity Hospital for Research and Training, Department of Obstetrics and Gynecology, Istanbul, Turkey.
authors: H
authors: H
authors: Fehmi Yazıcıoğlu
authors: Osman
authors: O
authors: Sevket
authors: Hale
authors: H
authors: Akın
authors: Mehmet
authors: M
authors: Aygün
authors: Osman Nuri
authors: ON
authors: Özyurt
authors: Ayse
authors: A
authors: Karahasanoğlu
mesh_terms: D000328:Adult; D000783:Aneurysm / Q000000981:diagnostic imaging*; D018376:Cardiovascular Abnormalities / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D015331:Cohort Studies; D003680:Deglutition Disorders / Q000000981:diagnostic imaging*; D004314:Down Syndrome / Q000000981:diagnostic imaging*; D005260:Female; D005333:Fetus / Q000002:abnormalities*; D006801:Humans; D016013:Likelihood Functions; D008875:Middle Aged; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D013348:Subclavian Artery / Q000002:abnormalities / Q000000981:diagnostic imaging; D014421:Turkey; D016216:Ultrasonography, Prenatal; D055815:Young Adult