What is the definition of pulsatile umbilical venous flow in twin-twin transfusion syndrome?

Am J Obstet Gynecol. 2008 Dec;199(6):634.e1-4. doi: 10.1016/j.ajog.2008.05.025. Epub 2008 Jul 17.

Abstract

Objective: The aim of the study was to derive an objective definition of pulsatile umbilical venous flow (PUVF).

Study design: Pulsed Doppler waveform analysis of the umbilical vein was performed in stages III and IV twin-twin transfusion syndrome (TTTS) patients. In patients with PUVF, the umbilical vein maximum (Vmax) and the umbilical vein minimum velocity (Vmin) and the resistance index for the umbilical vein (UVRI) = (100 x [Vmax - Vmin]/Vmax) were assessed.

Results: PUVF was noted in 130 of 226 stages III and IV TTTS patients. Digital images were available for analysis in 65 of 130 patients (50%). The minimum UVRI associated with PUVF was 16% for stages III and IV TTTS. There was a trend for increasing UVRI with stage (P = .052). Stage IV patients were more likely to have an UVRI greater than 30% (P = .02).

Conclusion: PUVF can be defined as an UVRI greater than 15%. A scale definition of PUVF may further facilitate assessment of the degree of fetal hemodynamic compromise.

MeSH terms

  • Adult
  • Cohort Studies
  • Female
  • Fetofetal Transfusion / diagnostic imaging*
  • Fetofetal Transfusion / physiopathology
  • Gestational Age
  • Humans
  • Pregnancy
  • Pregnancy Outcome
  • Pregnancy, High-Risk
  • Pregnancy, Multiple*
  • Probability
  • Pulsatile Flow / physiology*
  • Retrospective Studies
  • Risk Assessment
  • Sensitivity and Specificity
  • Statistics, Nonparametric
  • Terminology as Topic
  • Twins, Monozygotic
  • Ultrasonography, Doppler, Pulsed*
  • Ultrasonography, Prenatal
  • Umbilical Veins / diagnostic imaging*
  • Vascular Resistance / physiology