The Umbilical Cord
Gastroschisis is characterized by
NO overlying sac or peritoneum covering the abdominal wall contents and them freely protruding
What is another name for membranous insertion of the cord?
Velamentous insertion of the cord
The umbilical cord is surrounded by gelatinous stroma called
Whartons jelly
Gastroschisis involves ___ layers of the abdominal wall and measures ______
all, 2-4 cm
The _______ vessels become the umbilical vessels
allantoic
With marginal insertion of the cord (battledore placenta) the cord implants into the
edge of placenta instead if the middle
Hematoma of the cord may be caused by trauma which results in
extravasation of blood into Wharton's Jelly
Umbilical herniation is when the intestines return normally to the abdominal cavity and then herniate PREnatally or POSTnatally due to
failure of anterior abdominal wall to close completely at the level of umbilicus
The umbilical arteries arise from the fetal ______ and course alongside the ______
iliac arteries, fetal bladder
Focal dilatation of the umbilical veins is almost always ___________ but _____ in location
intra-abdominal, extra hepatic
Umbilical cord stricture is uncommon but distinctive condition associated with
intrauterine fetal death
US detection of SUA should prompt
investigation of further fetal anomalies
The arteries are spiral with the ______
larger umbilical vein
On US the umbilical vein curves toward the ________ rather than toward the liver
left sided stomach
The ____ umbilical artery is absent more often than the _____ umbilical artery
left, right
After birth, the ductus venosus transforms into the
lig. venosum (2nd week after birth)
Coiling of the cord is ____ and related to ______
normal, fetal activity
What is the most common cord entanglement in fetuses?
nuchal cord
Thrombosis of the umbilical vessels is defined as
occlusion of one or more vessels of umbilical cord
The umbilical cord forms as a fusion of the ___________ ______ _____ and ______ ______
omphalomesenteric yolk stalk, allantoic stalk
The umbilical cord in an essential link for _____ and ______ among the fetus, placenta and mother
oxygen, nutrients
The umbilical vein transports _____ blood TO the _______ from the _______
oxygenated, fetus, placenta
The ductus venosus forms the conduit between the ________ and the _________
portal system, systemic veins
Vasa previa is defined as the
presence of umbilical cord vessels crossing the internal os of cervix
Persistence of __________ rather than normal __________ is called _______
right portal vein, left-sided portal vein, intrahepatic right portal vein
Fetus with a _____ twist in the cord has a higher incidence of fetal anomalies than one with a _____ twist
right, left
The intra-abdominal portion degenerates after birth and becomes the
round ligament of liver (lig. of teres hepatis)
The cord length in twins is ____ than in singletons
shorter
Umbilical cord stricture results in
stillborn
With SUA, in the long axis view, the two vessel cord appears
straight and non coiled
The yolk stalk is the umbilical duct connecting the _____ with the _____
yolk sac, embryo
Thrombosis of the umbilical vessels primarily occurs in the ____
umbilical vein
Cord insertion into the _______ abdominal wall is an important landmark
ventral
______ is most frequently involved in hematoma of the cord
Umbilical vein
The length of the umbilical cord is determined by what two things?
-amount of amniotic fluid present in the 1st and 2nd trimesters -fetal mobility
True knots are associated with
-long cords -polyhydramnios -IUGR -monoamniotic twins
The amniotic membrane covers
1) the fetal surface of placenta 2) the multiple vessels that branch from the umbilical arteries
What two factors contribute to the failure of fetus to fill pelvic inlet cavity?
1. small presenting part 2. increased frequency of abnormal presentation in premature labor
After ____ weeks gestation, amniotic fluid volume increases rapidly due to _____
10, fetal voiding
The normal diameter of the cord is up to ___
2 cm
There are ____ arteries and ___ vein in the umbilical cord
2, 1
Short umbilical cords LESS than _____ are associated with _____
35 cm, oligohydramnios
The normal cord measures _______ in length
40-60 cm
The umbilical cord forms during the first ____ weeks gestation or ____ menstrual weeks
5, 7
Intestines grow at faster rate that the abdomen, therefore they herniate at ___ weeks and remain there until _____ weeks
7, 10
Long umbilical cords GREATER than _____ are associated with _______
80 cm, polyhydramnios
The umbilical cord can be visualized by the ____ week until term
8th
________ and ______ are FOCAL dilations of umbilical vessels affecting the umbilical artery and vein
Aneurysm, varix
Prolapse of the umbilical cord occurs when the cord lies
BELOW the presenting part
What is another name for marginal insertion of the cord?
Battledore Placenta
__________ is useful for recording absence of blood flow within umbilical cord
Color Doppler
___________ and cord length are roughly equivalent during the 1st trimester
Crown Rump Length
A probable cause for single umbilical artery (SUA) is ______ of one of the umbilical arteries in early development
atrophy
Fetal mortality is high in the premature population secondary to _______ and _____
birth trauma, anoxia
Falso knots of the umbilical cord are seen when
blood vessels are longer than cord (kinking of vessels to accommodate to length of cord)
The umbilical cord should normally insert into the______ of the placenta
center
The umbilical vein is formed by the confluence of the __________
chorionic veins of the placenta
Ompahlocele is characterized by the
complete covering of the intestines by a peritoneal amniotic membrane
________ of the cord reduces or cuts off blood supply to the fetus and may result in fetal demise
compression
The presence of more than three vessels in the cord has been documented with
conjoined twins
Wharton's jelly is an important structure to recognize when performing __________
cordocentesis
Omphalomesenteric cyst
cystic lesion of the umbilical cord caused by persistence and dilatation of segment of omphalomesenteric duct
The absence of cord twisting is an indirect sign of
decreased fetal movement
The paired umbilical arteries carry ______ blood from the _____ to the _____
deoxygenated , fetus, placenta
True knots of the umbilical cord arise from
fetal movements and are more likely in early pregnancy (also from venous stasis and thrombosis)
All pregnancies with single umbilical artery has a transverse umbilical artery diameter _____
greater than 4 mm
The sites of origin for hemangioma of cord are the
main vessels of umbilical cord, usually arises from um. artery
With membranous (velamentous) insertion of the cord, the cord inserts into the
membranes before it enters the placenta rather than inserting directly into placenta
Omphalocele is a type of umbilical cord mass that results from
the failure of intestines, liver and other organs to return to the abdominal cavity