Abnormal ductus venosus waveforms

Abnormal ductus venosus waveforms can arise in a number of conditions ranging from aneuploidy to vascular malformations and fetal tumors. "A wave" reversal can be seen in 5% of euploid fetuses ⁹.

Pathology

Abnormal waveforms in fetal ductus venosus flow assessment can occur in a number of situations:

• aneuploidic anomalies
  • Down syndrome: around 80% are thought to have abnormal waveforms
• congenital cardiac anomalies
  • fetal pulmonary arterial anomalies
    • congenital pulmonary stenosis
    • pulmonary atresia
• fetal arteriovenous malformations leading to shunting
  • vein of Galen malformation
• fetal tumors that lead to arteriovenous shunting
  • sacrococcygeal teratoma
  • epignathus
• twin-to-twin transfusion syndrome: recipient twin
• maternal diabetes: may exhibit increased PI values ⁷

Radiographic features

Abnormal waveforms include:

• absent flow in ductus venosus A wave
• reversal of flow in ductus venosus A wave
• abnormal indices:
  • abnormal pulsatility index (PI)
  • abnormal S wave to A wave ratio (S:A)
  • abnormal peak velocity index

Treatment and prognosis

Growth restricted fetuses with abnormal ductus venosus flow have worse perinatal outcomes compared to those where the flow abnormality is confined to the umbilical or middle cerebral artery ⁸.