Umbilical Vein Varix in Pregnancy

Umbilical Vein Varix

Umbilical vein varix is a focal dilatation of the umbilical vein that exceeds normal diameter for gestational age

1. Intra-abdominal umbilical vein varix (classic type)
Most common and best studied.
Location
• Between the anterior abdominal wall and portal sinus
• Inside the fetal abdomen

Intra-abdominal umbilical vein varix
Most common
Location
• Between the anterior abdominal wall and portal sinus
• Inside the fetal abdomen

Umbilical vein varix at insertion
Varix at abdominal wall insertion
• Just before the umbilical vein enters the fetal abdomen

Diagnostic criteria
Size criteria
• Umbilical vein diameter
o 9 mm at term
o 1.5 × diameter of adjacent normal umbilical vein

Doppler features that matter

Benign features
• Laminar venous flow
• No turbulence
• Stable size
• No intraluminal echoes

Concerning features
• Turbulent or bidirectional flow
• Progressive enlargement
• Echogenic intraluminal material (thrombosis)
• Absent or reduced downstream flow

Fetal and placental complications
• Venous thrombosis
• Fetal growth restriction
• Hydrops (rare)
• Intrauterine fetal demise

Prognosis
Isolated intra-abdominal UVV
• Generally favorable prognosis
• Most fetuses do well with surveillance
• Perinatal outcome is usually normal

UVV at insertion
• Slightly higher risk of:
o Thrombosis
o Acute fetal demise (rare, unpredictable)

Follow-up strategy
• Ultrasound every 1–2 weeks
• Assess:
o Varix size
o Flow pattern
o Evidence of thrombus
• Serial growth scans
• Umbilical artery and venous Dopplers

Counseling
• This is a vascular dilatation
• Many cases, especially when isolated, do well
• We monitor closely because rare complications can occur
• Stability over time is reassuring
• Sudden events are rare but explain the need for surveillance