Fetal Anomalies

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Anita Nowak, RDMS, MBA
Manager, Imaging
Magee-Womens Hospital of UPMC
 Anencephaly
 Spina
Bifida
 Cleft Lip
 Gastroschisis/Omphalocele
 Trisomy 18
 Conjoined Twins
Looking at Ultrasounds is very much like
looking at clouds
Use your imagination to find the cat in the
ultrasound
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The absence of the cranial vault
If early in pregnancy, brain tissue can be seen
Head has an irregular shape
There is no soft tissue seen above the orbits
Face – eyes appear “frog like”
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There are many forms of neural tube defects,
Spina Bifida is the most common of the
central nervous system
A midline defect of the vertebrae that results
in exposure of the contents of the neural
canal
Can be genetic
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Meningocele
◦ Anechoic cystic mass
◦ Rarely covered by skin
◦ Does not contain neural tissue
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Myelomeningocele
◦ Complex cystic mass
◦ Contains neural tissue
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Chiari II Malformation seen in 99% of cases
◦ Absent cisterna magna
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“Banana Sign” Abnormal cerebellum
Ventriculomegaly
Lemon shaped calvarium
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2nd most common congenital malformation
Estimated to be 1:700 live births
50% both lip and palate are defective
Can be caused by both genetic and
environmental factors
97% of the time it is an isolated finding
Occurs shortly after 3rd week of gestation when
the grooves that separate the structures that
form the primitive oral cavity persist, they would
normally be obliterated by normal growth.
Most commonly seen is a unilateral cleft
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Upper lip defect on nose/mouth view
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Gastroschisis is a paraumbilical defect of the
anterior abdominal wall.
Incidence ranges from 1:10,000 to 1:15,000
Is not associated with an increased risk of
other anomalies
Not usually associated with a chromosomal
abnormality
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Normal umbilical cord insertion site
Small bowel loops seen in the amniotic cavity
No covering membrane over the loops of
bowel
Can include stomach and large bowel
Majority occur to the right of the umbilical
cord
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A ventral wall defect where there is herniation
of the intraabdominal contents into the base
of the umbilical cord
Unlike gastroschisis, there is a membrane
covering these contents
Estimated to occur in 1:5800 to 1:5130
Most cases are sporadic
Unlike gastroschisis this condition IS often
associated with a chromosomal abnormality
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Umbilical cord insertion is typically midline
on the mass
Located centrally
Typically the contents of the mass are liver
and small bowel; however, other abdominal
organs can be present
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Also called Edwards Syndrome
There are three 18th chromosomes instead of
two
Multiple major anomalies are seen
Occurs in approximately 1:2500 pregnancies
50% carried to term will be stillborn
Of those that survive, only 10% survive to
their first birthday
Not genetic – typically occur sporadically
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Clenched Hands
Choroid plexus cysts
“Strawberry” shaped head
Intrauterine growth restriction
Cardiac defects
Micrognathia
Low set ears
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Incidence is 1:50,000 to 1:100,000
Sporadic event caused by an incomplete
division of the embryonic cell mass
Different types of conjoined twins
◦ Craniopagus – joined at the brain
◦ Thoracopagus – joined at the heart
◦ Omphalopagus – Xiphopagus – joined at the
abdomen
◦ Pygopagus – joined at the buttocks and lower spine
◦ Ischiopagus – joined at the hips
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Joined on any
portion of the skull
except the face
Share the bones of
the cranium
Have two trunks,
four arms and legs
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Most common form of
conjoined twins
Congenital heart disease
found in 75% of cases
The union always
includes the heart
Most frequent
abnormality is a
conjoined heart with two
ventricles and a varying
number of atria
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Attached in the lower
abdomen
Remain facing each
other throughout the
exam
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Joined at the
buttocks and lower
spine
Face away from
each other
Have one anus, two
rectums, four arms
and legs
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Joined end to end
with the spine in a
straight line
Four arms and a
variable number of
legs
Have only one
external genitalia
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