In the fetus, the vein carries ______ blood to the fetus, whereas the arteries bring venous blood back to the _____
oxygenated; placenta
When can the umbilical cord be visualized sonographically?
8 weeks to full term
When does the umbilical cord form?
first 5 weeks gestation
Fusion of which two vessels is the umbilical cord?
omphalomesenteric (yolk stalk) and allantoic ducts
Why is the insertion of the umbilical cord important?
to look for abdominal wall defects (omphalocele and gastroschisis) and limb-body wall complex
<p>When do the intestines normally herniate into the umbilical cord?</p>
<p>7 weeks and stay till 12 weeks gestation</p>
What is the normal diameter of the umbilical cord?
1-2 CM
What is the normal length of the umbilical cord?
40-60 cm
Where do the umbilical arteries arise from?
The fetal internal iliac arteries which course along the fetal bladder and exit the umbilicus to form part of the umbilical cord
Which vessel does the umbilical vein join after it enters the umbilicus?
the left portal vein
What does the umbilical vein become after birth?
the round ligament aka ligamentum teres
What does the umbilical cord consist of?
2 arteries and one vein
Where does the umbilical blood travel after it leaves the left portal vein?
travels through the ductus venosus to the systemic veins (IVC or hepatics), bypassing the liver, or through the right portal sinus to the right portal vein
What does a short umbilical cord measure?
less than 35 cm
What does a long umbilical cord measure?
greater than 80 cm
What conditions are associated with short umbilical cord?
oligohydramnios, restricted space (as in multiple gestations) intrinsic fetal anomaly, tethering of the fetus by an amniotic band, inadequate fetal descent, cord compression, fetal distress
Is coiling of the umbilical cord normal?
yes; may coil as many as 40 times, and usually to the left and near the fetal insertion site
What is an indirect sign of decreased fetal movement?
absence of cord twisting
Preterm delivery, decreased heart rate during delivery, meconium staining secondary to fetal distress, and fetal anomalies are other obstetric problems associated with?
short umbilical cord
Polyhydramnios, nuchal cord, true cord knots, umbilical cord compression, cord presentation and prolapse of the cord leading to fetal distress, umbilical cord stricture or torsion resulting from excessive fetal motion are all associated with?
long umbilical cord
Variations in cord diameter are usually attributed to diffuse accumulation of what?
Wharton’s Jelly
Variation in cord diameter are associated with?
maternal diabetes, edema secondary to fetal hydrops, Rh incompatibility and fetal demise
Masses associated with the umbilical cord are?
omphalocele, gastroschisis, umbilical herniation, teratoma of the umbilical cord, aneruysm of the cord, varix of the cord, hematoma of the cord, true knot, angioma, thrombosis
What results from failure of the intestines to return to the abdomen?
Omphalocele
What is a congenital defective opening in the wall of the abdomen just to the right of the umbilical cord; bowel and other organs may protrude outside the abdomen from this opening?
gastroschisis
What is it when the intestines return normally to the abdominal cavity and then herniate prenatally or postnatally through an inadequately closed umbilicus?
Umbilical Herniation
What is a cystic lesion of the umbilical cord caused by persistence and dilatation of a segment of the omphalomesenteric duct lined by epithelium of GI origin?
Omphalomesenteric Cyst
Does omphalomesenteric cyst affect males or females?
females
What is surrounded by edema and myxomatous degeneration of Wharton’s Jelly?
Hemangioma of the Cord
What happens when usually trauma causes extravasation of blood into Wharton’s Jelly?
hematoma of the cord
What is occlusion of one or more vessels of the umbilical cord and primarily occurs in the umbilical vein?
Thrombosis of the umbilical vessels
Associated with long cords, polyhydramnios, IUGR and monoamniotic twins
True knots
What is seen when blood vessels are longer than the cord?
false knots
What is the most common cord entanglement in the fetus?
nuchal cord
What is it called when the umbilical cord implants into the edge of the placenta is called?
Battledore placenta
What is it when the cord inserts into the membranes before it enters the placenta, rather than inserting directly into the placenta?
membranous or velamentous insertion of the cord
What type of insertion is associated with higher risk of low birth weight, small for gestational age, preterm delivery, low Apgar scores, and abnormal intrapartum fetal heart rate pattern?
Velamentous umbilical cord insertion
In 10% of cases, esophageal atresia, obstructive uropathies, congenital hip dislocation, spina bifida, ventricular septal defect, and cleft palate are associated anomalies of?
velamentous umbilical cord insertion
What is the presence of umbilical cord vessels crossing the internal os of the cervix?
Vasa previa
Congenital anomalies in 20%-50% of cases, increased incidence of IUGR, increased perinatal mortality, and increased incidence of chromosomal abnormalities are associated with?
single umbilical artery
Which organ systems are affected by SUA?
musculoskeletal 23%
Cardiac defects, skeletal abnormalities, abdominal wall defcts, diaphragmatic hernia, holoprosencephaly and hydrocephalus are major anomalies of?
SUA