title: First-trimester ductus venosus velocimetry in relation to nuchal translucency thickness and fetal karyotype.
abstract: OBJECTIVE
  To evaluate first-trimester ductus venosus flow in relation to nuchal translucency (NT) and fetal karyotype.
  
  
  METHODS
  Ductus venosus flow was measured in fetuses with NT greater than or equal to the 95th centile (group A) and in fetuses with NT less than the 95th centile (group B). The waveforms were classified as normal if the lowest forward velocity during atrial contraction (ACV) was positive and abnormal if it was absent or negative. The results were compared with the fetal karyotype.
  
  
  RESULTS
  Ductus venosus measurement was carried out in 330 fetuses. In group A, there were 156 fetuses: in 4 cases, it was not possible to obtain the measurement, and in the other 152 cases, 93 (61%) had a normal ACV and 59 (39%) an abnormal ACV. NT thickness was significantly greater in fetuses with abnormal ACV. In 34 out of 156 cases (22%), chromosomal abnormalities were found. Twenty-three chromosomopathies out of 33 (70%) had an abnormal ACV, and 10 (30%) had a normal ACV. A significant association between abnormal karyotype and abnormal ACV was found. Ductus venosus measurement was carried out in 174 fetuses of group B. In 1 case, it was not possible to obtain the measurement. One hundred and seventy-one (99%) cases had a normal ACV, and in 2 (1%) cases the ACV was abnormal. No chromosomal abnormalities were found in group B. Considering group A and group B, a significant association between the finding of an enlarged NT and abnormal ACV was detected (p < 0.05).
  
  
  CONCLUSIONS
  An abnormal ACV is more frequent in fetuses presenting enlarged NT than in those having normal NTs and in fetuses having the larger nuchal thickness. The probability of having a chromosomal abnormality in fetuses with enlarged NT is greater when an abnormal ACV is found.
authors.affiliation: Department of Obstetrics and Gynecology, Prenatal and Preimplantation Genetic Diagnosis and Fetal Therapy, Ospedale Microcitemico, Cagliari, Italy.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Zoppi
authors.forename: Monica
authors.initials: M
authors.lastname: Putzolu
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Ibba
authors.forename: Marcella
authors.initials: M
authors.lastname: Floris
authors.forename: Giovanni
authors.initials: G
authors.lastname: Monni
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D005333:Fetus / Q000098:blood supply* / Q000502:physiology*; D006801:Humans; D007621:Karyotyping; D009333:Neck / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012212:Rheology; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014680:Veins / Q000000981:diagnostic imaging