title: The role of ductus venosus blood flow assessment in screening for chromosomal abnormalities at 10-16 weeks of gestation.
abstract: OBJECTIVE
  To evaluate the role of ductus venosus blood flow assessment at 10-16 weeks' gestation in screening for chromosomal abnormalities.
  
  
  METHODS
  Ductus venosus blood flow was prospectively evaluated in 1371 consecutive pregnancies between 10 and 16 weeks of gestation. The pulsatility index for veins was calculated. All cases were screened for chromosomal defects combining maternal age and fetal nuchal translucency thickness.
  
  
  RESULTS
  A chromosomal abnormality was found in 20 cases. The overall detection rate, specificity, positive predictive value, negative predictive value and odds ratio for chromosomal abnormalities were 65%, 95.7%, 18.3%, 99.5% and 41 (95% CI 16-108), respectively, when using the 95th centile pulsatility index as a cut-off.
  
  
  CONCLUSIONS
  These preliminary results suggest that evaluation of the ductus venosus pulsatility index at 10-16 weeks' gestation is a useful second-line screening test for chromosomal defects. A combination of nuchal translucency measurement and ductus venosus assessment might increase specificity while maintaining an optimal detection rate for chromosomal abnormalities. Such a policy could identify 55% of all chromosomal abnormalities and about 69% of autosomal trisomies, reducing the need for invasive testing to less than 1%.
authors.affiliation: Departmento de Obstetricia y Ginecología, Institut Universitari Dexeus, Paseo Bonanova 67, Barcelona 08017, Spain. marant@iudexeus.uab.es
authors.forename: E
authors.initials: E
authors.lastname: Antolín
authors.forename: C
authors.initials: C
authors.lastname: Comas
authors.forename: M
authors.initials: M
authors.lastname: Torrents
authors.forename: A
authors.initials: A
authors.lastname: Muñoz
authors.forename: F
authors.initials: F
authors.lastname: Figueras
authors.forename: M
authors.initials: M
authors.lastname: Echevarría
authors.forename: M
authors.initials: M
authors.lastname: Cararach
authors.forename: J M
authors.initials: JM
authors.lastname: Carrera
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D016009:Chi-Square Distribution; D002869:Chromosome Aberrations / Q000000981:diagnostic imaging*; D025063:Chromosome Disorders; D016001:Confidence Intervals; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007621:Karyotyping; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011446:Prospective Studies; D011673:Pulsatile Flow; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal