title: Hemodynamic impact of absent or reverse end-diastolic flow in the two umbilical arteries in growth-restricted fetuses.
abstract: OBJECTIVE
  To determine if bilateral absent or reverse end-diastolic (ARED) flow in the two umbilical arteries (UAs) at the perivesical (PVC) segment represents a more severe degree of hemodynamic compromise than unilateral ARED flow at the PVC segment in singleton pregnancies complicated by intrauterine growth restriction (IUGR).
  
  
  METHODS
  This was a prospective observational study. One hundred nine fetuses with IUGR underwent a total of 225 ultrasound (US) examinations. We measured the pulsatility index (PI) from the two UAs at the PVC segment, UA in the free floating cord (FFC), middle cerebral artery (MCA), ductus venosus (DV) and the aortic isthmus blood flow index (IFI). Three groups were classified according to bilateral positive end-diastolic (PED) flow, unilateral ARED flow or bilateral ARED flow in the UAs at the PVC segment.
  
  
  RESULTS
  The proportions of US examinations with PED flow, unilateral ARED flow and bilateral ARED flow in the UAs were 54.7%, 20.4%, and 24.9%, respectively. At the last US examination, the IFI z-scores were significantly lower in the bilateral ARED group (-6.28 ± 4.30) compared to the unilateral ARED group (-1.72 ± 3.18, p<0.05) and the bilateral PED group (-0.83 ± 2.36, p<0.05), the DV-PI z-scores were significantly higher in the bilateral ARED group (2.15 ± 3.79) compared to the bilateral PED group (0.64 ± 1.50, p<0.05). Before 32 weeks of gestation, the interval between US examination and delivery was significantly shorter in the bilateral ARED group (8.9 days ± 8.2) than the unilateral ARED group (15.9 days ± 13.4, p<0.05) and the bilateral PED group (30.3 days ± 25.7, p<0.05).
  
  
  CONCLUSIONS
  There are significant differences in fetal blood fluxes between left and right UA. Doppler examination at the PVC segment significantly improves the comparability of UA-PI between two successive US examinations and allows a longitudinal and independent hemodynamic investigation of each UA. Examination of a single UA in free floating cord may miss a large fraction of unilateral ARED flow. In singleton IUGR fetuses, a bilateral ARED flow in the UAs at the PVC segment indicates more severe hemodynamic compromise and worse fetal conditions than unilateral ARED flow.
authors: Obstetrics and Gynecology Unit, Maternité Port-Royal, APHP, Paris Descartes University, Paris, France.
authors: Edouard
authors: E
authors: Lecarpentier
authors: Anne Gaëlle
authors: AG
authors: Cordier
authors: Francine
authors: F
authors: Proulx
authors: Jean Claude
authors: JC
authors: Fouron
authors: Laurence
authors: L
authors: Gitz
authors: Gilles
authors: G
authors: Grange
authors: Alexandra
authors: A
authors: Benachi
authors: Vassilis
authors: V
authors: Tsatsaris
mesh_terms: D000328:Adult; D003971:Diastole / Q000502:physiology*; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D011247:Pregnancy; D014469:Umbilical Arteries / Q000503:physiopathology*