title: Sonographic measurement of the fetal iliac angle in trisomy 21, 18 and 13.
abstract: OBJECTIVE
  To determine whether iliac wing angle measurement in second trimester fetuses is a useful sonographic marker for the detection of trisomy 21, 18 and 13.
  
  
  METHODS
  During the period between September 1998 and September 2001, 406 fetal iliac angle measurements were performed in women in the second trimester of their pregnancies. The iliac angle measurements in fetuses with trisomy 21 (n = 25), trisomy 18 (n = 10) and trisomy 13 (n = 5) were compared with iliac angle measurement in fetuses with normal karyotypes (n = 333).
  
  
  RESULTS
  The mean iliac wing angle in the fetuses with trisomy 21 was 92.67 and 79.35 degrees and 74 degrees in fetuses with trisomy 18 and 13 (the mean iliac wing angle in the healthy fetuses was 70.09 degrees ).
  
  
  CONCLUSIONS
  The proven larger iliac wing angle in neonates with Down's syndrome can be demonstrated sonographically during the pregnancy, especially during the second trimester, and may be useful in prenatal screening of trisomy 21. The sonographic measurement of the fetal iliac angle cannot be used as a marker for trisomy 18 and 13. We have shown that fetuses with trisomy 18 and 13, on average, have iliac angles only a few degrees larger than healthy fetuses.
authors.affiliation: Semmelweis University, First Department of Obstetrics and Gynecology, Budapest, Hungary. bezo@noi1.sote.hu
authors.forename: Zoran
authors.initials: Z
authors.lastname: Belics
authors.forename: Artur
authors.initials: A
authors.lastname: Beke
authors.forename: László
authors.initials: L
authors.lastname: Csabay
authors.forename: István
authors.initials: I
authors.lastname: Szabó
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Papp
mesh_terms: D015415:Biomarkers; D004314:Down Syndrome / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007085:Ilium / Q000000981:diagnostic imaging*; D008403:Mass Screening; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012680:Sensitivity and Specificity; D014314:Trisomy / Q000175:diagnosis*; D016216:Ultrasonography, Prenatal / Q000379:methods*
chemical_list: D015415:Biomarkers