What is the outpouching from the primitive gut that forms umbilical vessels during development?
Allantois
This occurs between 12–16 weeks of gestation.
At 6 weeks, how many umbilical arteries and veins are present?
- 2 umbilical arteries
- 2 umbilical veins
This is part of the normal development of the umbilical cord.
What happens to the right umbilical vein by 8 weeks?
It regresses
The left umbilical vein remains.
What is the function of the umbilical vein?
Carries oxygenated blood to the fetus
This is part of the normal anatomy of the umbilical cord.
What do the two umbilical arteries carry?
Deoxygenated blood from the fetus
This is essential for fetal circulation.
What is Wharton’s Jelly?
Mucous connective tissue that protects vessels
It surrounds the umbilical vessels.
What is the typical length of the umbilical cord by 28 weeks?
~50–60 cm
This is considered a normal measurement for the umbilical cord.
Where is the insertion site of the umbilical cord normally located?
(placenta)
Central in the placenta
This is important for proper fetal development.
What is the S/D Ratio in umbilical cord Doppler evaluation?
Systolic / Diastolic (Normal < 3 after 30 weeks)
This ratio helps assess blood flow.
What does AEDF stand for in umbilical cord Doppler evaluation?
Absent end-diastolic flow
This indicates abnormal flow and is considered bad.
What is a common indication for umbilical cord Doppler evaluation?
- Maternal diseases (HTN, diabetes, anemia, Rh, renal, smoking)
- Elevated AFP
- IUGR
- Oligohydramnios
- Suspected cord abnormalities
- Congenital/chromosomal anomalies
These conditions may affect fetal well-being.
What is the most common vessel abnormality in umbilical cords?
Single Umbilical Artery (SUA)
SUA is associated with Trisomy 18 and other defects.
What is a marginal insertion of the umbilical cord?
Cord inserts <2 cm from edge
Common in twins and can cause growth discordance.
What is a velamentous insertion?
Vessels insert into membranes, not protected by Wharton’s jelly
This increases risks such as vasa previa and fetal death.
What is the risk associated with vasa previa?
Fetal vessel rupture with high mortality
This condition poses a significant risk during delivery.
What does a hypocoiled cord indicate?
Increased risk of IUGR and distress
Cord coiling can affect fetal health.
What is the risk a true knot in the umbilical cord?
Risk of asphyxia and fetal death
It may be seen as a ‘hanging noose’ sign on ultrasound.
what precent of cord hematoma result in still birth
47%
Hematomas can occur post-cordocentesis.
What is the most common cord tumor?
Hemangioma
Often found near placental insertion and associated with increased AFP.
What is an omphalomesenteric cyst?
Embryological remnant found near fetal cord insertion
Linked to Meckel’s diverticulum.
True or false: Umbilical herniation is clinically significant and common in Trisomy 21.
FALSE
It is common in early infancy and resolves after birth.
What is the location of an allantoic cyst?
Anechoic cyst at fetal end of cord
It usually does not affect circulation.
