Test 4 Part 1 Flashcards
where does the umbilical vein enter?
left portal vein
where do the umbilical arteries arise from?
internal iliac (hypogastric) arteries
what is the umbilical cord bathed in?
wharton jelly
what does the umbilical artery do?
return venous blood back to the placenta
describe umbilical artery resistance
- low resistance near the fetal insertion
- high resistance near the placental inserton
what does the umbilical vein do?
carries oxygenated blood
describe the flow in the umbilical vein?
- continuous low flow through systole and diastole
- flow is directed from the placenta to the fetus
what does having a single umbilical artery increase the risk of?
associated fetal anomalies and IUGR
what does having a single umbilical artery associated with?
malformations of all major organ systems, chromosomal abnormalities
what is a nuchal cord?
-cord completely surrounds fetal neck with more than one loop
how does nuchal cord occur?
fetus will turn in and out of the umbilical cord throughout the pregnancy
what is a prolapsed cord?
cord precedes the fetus in the birth process
what is a battledore placenta (marginal)?
cord inserts into the end margin of the placenta
what is a circumvallate placenta?
abnormal placental shape in which the membranes insert away from the placental edge toward the center
what does having a circumvallate placenta increase the risk of?
- abruption
- IUGR
- premature labour
- perinatal death
what is a succenturiate placenta?
a result of the lack of the adjacent chorionic villi to atrophy
how many pregnancies does succeturiate placenta occur in?
5%
what does succenturiate placenta have an increased risk of?
velamentous cord and vasa previa
what is a chorioangioma?
placental hemangioma (no clinical significance when small)
how does a chorioangioma occur?
arises fromt he chorionic tissue of the amniotic surface of the placenta
what is a choriocarcinoma?
malignant form of trophoblastic disease
how does choriocarcinoma occur?
50% are preceeded by a molar pregnacy
what may a complete molar pregnancy may develop into?
choriocarcinoma
is a partial mole malignant?
carries little malignant potential
what is a velamentous cord insertion?
umbilical cord inserts into the membranes before entering the placenta
what is a velamentous cord not protected by?
wharton jelly
what is velamentous cord associated with?
- preterm labour
- abnormal fetal heart pattern
- low Apgar scores
- low birth weight
- IUGR
what is hydrocephaly?
a dilated ventricle with enlargment of the head
what is ventriculomegaly?
dilation of the ventricles without enlargment of the head
what is the most common intracranial abnormality detected by US?
ventriculomeglay
what terms are sometimes used interchangeably?
hydrocephaly and ventriculomegaly
what is associated with hydrocephaly and ventriculomegaly?
high morbidity and mortality
what may be the result of a congenital anomaly or aquired?
hydrocephalus
what does hydrocephaly lead to?
intracranial pressire compromising brain parenchyma
what may ventricular enlargment result from?
compensation for atrophy or abnormal development of brain parenchyma
what are causes of hydrocephaly?
- holoprosencepahly
- spina bifida
- encephalocele
- dandy-walker malformation
- aqueductal stenosis
- arachnoid cysts
- agenesis of the corpus callosum
what can hydrocephaly be associated with?
- congenital infections
- neoplasms
- MSK anomalies
- aneuploidy
what is holoprosencephaly?
encompasses a rangle of severity characterized by incomplete or lack of cleavag of the forbrain
what is the most severe holoprosencephaly?
alobar holoprosencephaly
describe alobar holoprosencephaly
- complete failure of separation of the forebrian
- fusion of the thalami, a single ventricle, and fusion of the cerebral hemispheres
what is absent in alobar holoprosencephaly?
- flax
- corpus callosum
- olfactory bulbs
- optic tracts
what is semilobar holoprosencephaly?
partial cleavage of the forebrain and absence of the corpus callosum and olfactory bulbs
describe lobar holoprosencephaly?
- mildest form
- seperation of the cerebrum
- fusion of the lateral ventricles
- absence of the corpus callosum
what is holoprosencephaly associated with?
- severe facial abnormalies
- including cyclopia
- ethmocephaly
- cebocephaly
- facial clefts
what chromosomal is holoprosencephaly associated with?
trisomy 13
what syndromes may holoprosencephaly be seen in?
- edwards syndrome (18)
- Smith-Lemli-Opitz syndrome
- Pallister Hall syndrome
who is holoprosencephaly more common in?
females
how is hydrancephaly characterized?
destruction of the brain parenchyma with replacement by cerebrospinal fluid
what are the causes of hydrancephaly?
- vascular malformation
- congenital infections
- cocaine abuse
how is dandy walker malformation characterized?
by absence or dysplasia of the cerebellar vermis and maldevelopment of the 4th ventricle with the replacement by a posterior fossa cyst
what is DWM associated with?
ventriculomagaly
what may DWM be isolated or associated with?
syndromes
aneuploidy
maternal infection
what intracranial anomalies is associted with DWM?
ACC
out of all infants who survive DWM, how many are intellectually impaired?
40%-70%
what is the purpose of the corpus collosum?
connects the cerebral hemispheres and aids in learning and memory
ACC may be found in ________
isolation
what can ACC be associated with?
other anomlaies of central nervous system, a variety of chromosomal anomlies, syndromes, and metabolic diseases
what are the symptoms of ACC?
asymptomatic or have a grave prognosis when severe anomalies are identified
what cysts in the brain resolve?
choroid plexus cysts
what are choriod plexus cysts associated with?
aneuploididy (mostly 18)
what should be done when a choroid plexus cyst has been identified?
a targeted sonogram to search for additional anomalies should be preformed
A new risk for aneuploidy can be given that combines ____________
the targeted scan and serum screen with maternal age and family history
what is the most comon congenital defect of the face?
cleft lip/palate
cleft palate occurs in approx ____ of cases of cleft lip
80%
what side are unilateral cleft more commonly?
left sided
what are median clefts and bilateral cleft associated with?
cleft palate
what does cleft lip/palate have an increased frequency of?
- aneuploidy
- skeletal anomalies
- syndromes
what is micrognathia?
small or recessed chin
what is micrognathia associated with?
- aneuploidy
- skeletal anomalies
- multiple syndromes
what are the most common anomalies associated with micrognathia?
trisomy 13 and 18
what plane is micrognathia identfied on US?
sag plane
what may be identified in associated with micrognathia?
polyhydramnois
what is congenital diaphrahmatic hernia?
herniation of abdominal contents into the thorax through a defect in the diaphragm
what has been assosiated with CDH?
gentic and teratogenic factors
which side is CDH more common on?
left side
what is CDH associated with?
- chromosomal anomalies
- defects of the central nervous system and heart
what is the most common sonogrpahic finding in CDH?
stomach above the diaphragm
what is congenital cystic adenomatoid malformation?
a rare lung abnormality charcterized by an overgrowth of terminal bronchopulmonary tissue
what is type 0 CCAM?
acinar dysplasia
what is type 1 CCAM?
macrocystic masses that consist of multiple large cyst
what is type 2 CCAM?
single large cyst and smaller cysts less than 1cm
what is type 3 CCAM?
a microcystic variety that appears as a large echogenic mass
what is a type 4 CCAM?
a peripheral cyst
is CCAM usually bilateral or unilateral?
unilateral involving one lung
what may CCAM be associated with?
- hydrops
- polyhydramnois
- pulmonary hypoplasia
what is pulmonary sequestration?
a rare abnormality characterized by a mass of lung tissue
what does pulmonary seqstration not connect with?
tracheobronchial tree
what does pulmonary sequestration have that is seperate?
seperate blood supply that usually originates form the abdominal aorta
which type of pulmonary sequestration has the most anomalies?
extralobar (may appear above or below the diaphragm)
what is pulmonary sequestration associated with postnatally?
- mediastinal shift
- pleural effusion
- hydrops
what are the outcomes for pulmonary sequestration?
newborns may die of pulmonary hypoplasia or be completely asymptomatc and need respiratory support or surgery to resect the sequestered lung
what is pulmonary effusion? (EF-hydrothorax)
a rare entity characterized by an abnormal accumulation of fluid in the fetal thorax
what is the outcomes of pulmoary effusion?
- resolve spontaneously
- lead to pulmonary hypoplasia
- progress to hydrops
- fetal death
what is pulmonary effusion associated with?
- CCAM
- pulmonary sequestration
- CDH
- cardiac defects
- chromosomal anomalies
- other structural defects
how can sonographic diagnosis be made of PE?
when fluid is identified in the fetal thorax surrounding lung tissue
