title: Longitudinal study of aortic isthmus Doppler in appropriately grown and small-for-gestational-age fetuses with normal and abnormal umbilical artery Doppler.
abstract: OBJECTIVE
  To establish reference ranges using longitudinal data for aortic isthmus (AoI) Doppler indices in appropriate-for-gestational-age (AGA) fetuses and to document the longitudinal trends in a cohort of small-for-gestational-age (SGA) fetuses with normal umbilical artery Doppler and in fetuses with intrauterine growth restriction (IUGR) and abnormal umbilical artery Doppler.
  
  
  METHODS
  AoI Doppler reference ranges were established from longitudinal data on 72 AGA singleton fetuses. Reliability of AoI Doppler flow measurements at two different sites and reproducibility between two operators was reviewed. A prospective longitudinal study of AoI Doppler indices in 48 SGA fetuses with normal umbilical artery Doppler and 10 IUGR fetuses was performed.
  
  
  RESULTS
  The AoI pulsatility index (PI) and peak systolic velocity (PSV) in AGA fetuses showed a significant increase with gestational age. Analysis of intra- and interoperator variability revealed no significant mean difference in measurements of AoI-PI or AoI-PSV. Observations of AoI-PI and AoI-PSV from SGA fetuses did not differ significantly from those of AGA or IUGR fetuses. Retrograde flow in the AoI did not predate changes in the ductus venosus in IUGR fetuses.
  
  
  CONCLUSIONS
  Reference ranges for fetal AoI Doppler parameters in AGA fetuses constructed using longitudinal data are consistent with those obtained from cross-sectional data. The AoI Doppler parameters in SGA fetuses did not differ from those in AGA fetuses. Preterm IUGR fetuses did not manifest alterations in AoI-PI or AoI-PSV prior to changes in biophysical profile or ductus venosus Doppler. Further large-scale prospective studies are needed to determine whether AoI Doppler parameters are of any value in timing delivery or reducing adverse neurodevelopmental outcome.
authors.affiliation: Ultrasound and Fetal Medicine Centre, Coombe Women and Infants University Hospital, Dublin, Ireland. mkennelly@doctors.org.uk
authors.forename: M M
authors.initials: MM
authors.lastname: Kennelly
authors.forename: N
authors.initials: N
authors.lastname: Farah
authors.forename: J
authors.initials: J
authors.lastname: Hogan
authors.forename: A
authors.initials: A
authors.lastname: Reilly
authors.forename: M J
authors.initials: MJ
authors.lastname: Turner
authors.forename: B
authors.initials: B
authors.lastname: Stuart
mesh_terms: D000328:Adult; D001013:Aorta, Thoracic / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000196:embryology / Q000503:physiopathology; D001783:Blood Flow Velocity; D015331:Cohort Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D010927:Placental Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D013997:Time Factors; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal / Q000379:methods; D014469:Umbilical Arteries / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000196:embryology / Q000503:physiopathology