Fetal Abnormalities Flashcards
What is acromelia?
Shortening of the bones of the hands or feet.
What is the aqueduct of Sylvius?
A channel between the third and fourth ventricles of the brain.
What does the banana sign indicate?
Crescent shape to the cerebellum displayed with a coexisting neural tube defect.
What is the corpus callosum? What function does it serve?
- A band of white matter tissue connecting the cerebral hemispheres
- Serves a function in both learning and memory.
Where is the Foramen of Monro located?
At the junction between the third ventricle and the paired lateral ventricles of the brain.
What is frontal bossing?
Protrusion or bulging of the forehead associated with hydrocephalus.
What is hydrocephalus?
Overt enlargement of the lateral ventricles secondary to an increase in intracranial pressure.
What does hypertelorism refer to?
Abnormally widespread position of the orbits.
What is hypotelorism?
Abnormally close position of the orbits.
What does the keyhole sign indicate?
Appearance of the dilated bladder superior to the obstructed male urethra.
What is concavity to the front bones of the fetal cranium associated with?
Spina bifida.
What does macroglossia refer to?
An excessively large tongue.
What is mesomelia?
Shortening of the middle portion of a limb.
What is rhizomelia?
Shortening of the proximal portion of a limb.
What does the steer sign indicate? What is it associated with?
- Enlargement and upper displacement of the third ventricle
- Associated with agenesis of the corpus callosum.
What is ventriculomegaly?
Ventricular enlargement characterized by excessive cerebrospinal fluid within the ventricles.
What is micromelia?
Shortening of all portions of a limb.
What is myelomeningocele?
A developmental defect of the central nervous system in which a hernial sac containing a portion of the spinal cord, its meninges, and cerebrospinal fluid protrudes through a congenital cleft in the vertebral column.
What does nuchal thickness measure?
The distance between the calvaria and posterior skin line.
What is proboscis?
Protrusion of nasal tissue above the orbits.
What is the vermis?
Structure located between the hemispheres of the cerebellum.
What are prominent sulcal markings associated with?
Abnormal migration of enchyma tissues.
What does it indicate if the skull is absent but the brain is present?
A significant developmental abnormality.
What are elevated alpha-fetoprotein levels associated with? 3
- Coexisting spinal defects
- Club foot
- Cleft lip, and palate.
What happens in the failure of callosal fibers to form?
Dilation and elevation of the third ventricle may be partial or complete.
What does outward angling and wide separation of the hemispheres indicate?
A potential cranial abnormality.
What is disproportionate enlargement of the occipital horns called?
Colpocephaly
Arachnoid cyst are cysts that arise from? 3
A cyst that can result from
1. Trauma
2. Infarction
3. Infection.
What is Dandy-Walker malformation?
A congenital malformation of the cerebellum with associated maldevelopment of the fourth ventricle.
What is the banana sign in sonography?
Compressed shape of the cerebellum through foramen magnum.
What is the lemon-shaped cranium associated with?
Arnold-Chiari malformation.
What does Dandy-Walker syndrome involve?
Enlarged posterior fossa and prominent posterior fossa.
What are common causes of Dandy-Walker syndrome? 3
- Alcohol abuse
- Autosomal recessive disorder
- Viral infection.
What is the significance of a cisterna magna greater than 10 mm?
It indicates potential abnormalities.
What is ventriculomegaly?
Increase in ventricular volume generally caused by outflow obstruction or decreased cerebrospinal fluid production.
What is hydranencephaly?
A condition where brain tissue is replaced by cerebrospinal fluid.
What characterizes alobar holoprosencephaly?
Large central single ventricle and fused thalami.
What is cyclopia?
A severe form of holoprosencephaly.
What is the mildest form of holoprosencephaly?
Lobar holoprosencephaly with two large lateral ventricles.
What is associated with spina bifida? (in the head)
Bilateral indentation of the occipital bone may be a normal finding.
What is anencephaly?
A result of infarction or hemorrhage leading to a small biparietal diameter.
What does decreased head circumference indicate? What is considered below normal?
It can indicate conditions like encephalocele, measuring more than 3 SD below normal.
What is characterized by a sloping forehead?
Anechoic mass within an area of the brain.
What is spina bifida?
A neural tube defect characterized by the failure of the cephalic end of the neural tube to close completely.
Associated with bulging eyes (froglike face) and absence of the cranial vault.
What disorder is midline brain shift associated with?
It is associated with Trisomy 18.
What are the sonographic findings of agenesis of the corpus callosum?
Prominent or dilated third ventricles and a single fluid space close to midline.
Variable in shape.
What is a cerebral arteriovenous malformation (AVM)?
A condition characterized by a dilated vein of Galen and turbulent blood flow within associated ventriculomegaly.
What is the significance of elevated alpha-fetoprotein (AFP) levels?
Elevated AFP levels can indicate neural tube defects and other malformations.
Associated with amniotic band syndrome and polyhydramnios.
Caudal regression is a condition more common with patients with what disorder?
A condition associated with skeletal dysplasia and more common in patients with diabetes.
What characterizes an encephalocele?
A defect in the bony calvarium allowing herniation of intracranial contents.
More common in the occipital region.
What is a cystic hygroma?
A spherical fluid-filled or complex mass extending from the calvaria.
What is the appearance of a cloverleaf skull deformity?
Characterized by a bony calvarial defect and herniation of brain tissue.
What does the term ‘occulta’ refer to? What happens to the AFP in this level?
A type of spina bifida where the defect is covered by normal soft tissues and has a normal AFP level.
What does ‘aperta’ indicate in spina bifida? What happens to the AFP in this level?
A type of spina bifida where the defect is uncovered, associated with elevated AFP levels.
What is anophthalmia?
The absence of the globe or the orbit, often associated with failure of the optic vesicle to form.
Documented best on the transaxial view at the level of the orbits.
What is cyclopia?
A condition characterized by midline fusion of the orbits resulting in a single midline orbit.
Associated with holoprosencephaly and Trisomy 13.
What is a facial cleft?
A defect caused by failed fusion of the maxilla, primary, and secondary palates.
What is Hypotelorism?
Orbits placed closer together than expected.
Most common facial abnormality.
What is Macroglossia?
Persistent protrusion of the fetal tongue.
Documented best on the sagittal profile view.
What is Micrognathia?
Small receding chin and lower lip.
Associated with Trisomy 18.
What is the best way to detect a defect of the upper lip and palate?
Documented best on the corona view.
Two thirds of cases include cleft palate.
What is Polyhydramnios?
Excess amniotic fluid.
Associated with various fetal abnormalities.
What is Nuchal edema?
Thickening of the nuchal fold.
Associated with chromosomal abnormalities.
What is Cystic hygroma?
Thin-walled multiseptated cystic mass in the neck, axilla, or mediastinum.
Associated with chromosomal abnormalities, fetal hydrops, and fetal heart failure.
What is Ectopia cordis?
Partial or complete displacement of the heart outside of the thorax.
Associated with intracardiac anomalies and omphalocele.
What is Diaphragmatic hernia?
Diaphragm fails to close allowing herniation of the abdominal cavity contents.
Associated with cardiac, renal, chromosomal, and central nervous system anomalies.
What is Cystic adenomatoid malformation?
Abnormal formation of the bronchial tree.
May be associated with renal or fetal hydrops.
If an umbilical cord has two arteries and one vein what kind of structure is it? How is it best documented?
Normal structure and function of the umbilical cord.
Documented best on the sagittal profile view.
What is the significance of the four-chamber heart view?
Visualizes displacement of the septal and posterior leaflets of the tricuspid valves into the right ventricle.
Associated with Tetralogy of Fallot.
What is Ectopia cordis?
A condition where the heart is located outside the thorax.
What kind of disease is Ebstein anomaly assocaited with? How common is it?
The most common form of cyanotic heart disease.
What anomalies is Polyhydramnios associated with?
Usually unilateral and associated with various anomalies.
What is a Diaphragmatic hernia?
A condition where the diaphragm fails to close, allowing herniation of abdominal cavity contents.
What is the association of Diaphragmatic hernia? (in terms of anomailies) 4
Associated with
1. Cardiac
2. Renal
3. Chromosomal
4. Nervous system anomalies.
What is Tetralogy of Fallot?
A congenital heart defect characterized by four specific heart abnormalities.
What is a Ventricular septal defect?
An opening in the ventricular septum allowing blood to flow between the ventricles.
What is Cystic adenomatous malformation and what disorder is it associated with?
A lung malformation that can be associated with diaphragmatic hernia.
What is a Bochdalek hernia? What kind of defect is it typically?
The most common type of diaphragmatic hernia, typically a posterolateral defect.
What common is Morgagni’s hernia? Which side is often affected?
A rare anterior diaphragm defect, often left-sided.
What is Fetal hydrops?
Fluid accumulation in the fetal chest, associated with various conditions.
What are the criteria for Ebstein anomaly? 3
- Includes ventricular septal defect
- Subaortic ventricular septal defect
- Overriding aorta.
What is hypertrophy of the right ventricle in the third trimester associated with?
It appears larger than normal.
Associated with the pulmonary artery.
What is transposition in cardiac anatomy?
The aorta arises from the right ventricle and the pulmonary arteries arise from the left.
The two great vessels do not crisscross but arise parallel from the base of the heart.
What are the sonographic findings of gastrointestinal tract obstruction?
Usually multiple structures within the fetal abdomen are affected.
Normal prominent loops of bowel may be observed.
What is duodenal atresia?
It is a blockage of the duodenum.
Characterized by a dilated, fluid-filled loop of bowel (double bubble).
What does elevated alpha-fetoprotein (AFP) indicate?
Not evident until after 20 weeks of gestation.
Associated with Trisomy 21 and anomalies in cardiac, urinary, and GI systems.
What is esophageal atresia?
A congenital malformation of the foregut characterized by the absence of the stomach.
Associated with tracheoesophageal fistula (90%).
What is polyhydramnios?
Excess amniotic fluid often associated with intrauterine growth restriction.
Possible association with echogenicity of the bowel.
What is meconium ileus?
Impaction of thick meconium in the distal ileum.
Frequently associated with cystic fibrosis.
What is meconium peritonitis?
Bowel perforation caused by bowel atresia or meconium.
What are common sonographic findings of abdominal calcification? 3
- Gallstone
- Bowel dilation
- Splenic calcification.
What is polyhydramnios?
Excess amniotic fluid.
What are congenital infections associated with hepatic necrosis?
Abnormalities of the Genitourinary System.
What is extrophy of the bladder?
Externalization of the bladder onto the anterior abdominal wall.
Also known as ectopia vesicae.
What is a cystic mass located in the umbilical cord?
Umbilical cord cyst.
What causes a wide separation of the pubic bones?
Caused by incomplete closure of the inferior part of the anterior abdominal wall.
What is hydronephrosis?
Urinary tract obstruction.
Prominent renal pelvis ratio above what value is significant?
Ratio of the renal pelvis diameter to the anterior-posterior renal diameter >50%.
What is infantile polycystic disease?
Bilateral renal disease with hyperechoic enlarged kidneys.
Extreme oligohydramnios is how dangerous of a condition? What does it result in pertaining to the urinary system?
Lethal condition with no visible or small fetal bladder.
What characterizes multicystic dysplastic kidney?
Kidney tissue is replaced by noncommunicating multiple cysts.
Who is primarily affected by posterior urethral valve obstruction? What do we see with it?
- Occurs in males
- Dilated bladder and presence of a membrane within the posterior urethra.
What is ureterovesical obstruction appearance?
Keyhole appearance with a dilated posterior urethra.
What is renal agenesis?
Absence of one or both kidneys.
Unilateral agenesis refers to the absence of one kidney, while bilateral agenesis refers to the absence of both kidneys.
What is oligohydramnios?
A condition characterized by low amniotic fluid volume.
It can lead to pulmonary hypoplasia and other complications.
What is hydronephrosis?
Overdistention of the urinary bladder due to urine unable to pass through the urethra.
Can cause severe damage to kidneys, ureters, and bladder.
What is the most common cause of hydronephrosis?
Ureteropelvic junction obstruction.
This is an obstruction between the renal pelvis and proximal ureter.
What does a normal fetal bladder indicate?
It suggests normal amniotic fluid volume levels.
Abnormalities may indicate issues such as hydronephrosis.
What is a multicystic dysplastic kidney?
A kidney with smooth, thin wall margins and posterior acoustic enhancement.
It is characterized by the presence of multiple cysts.
What is ureterovesical junction obstruction?
An obstruction that results from a urethral issue, leading to a dilated renal pelvis and ureter.
This can result in a megaureter.
What are the potential complications of unilateral ureteral obstruction?
Possible secondary hydronephrosis.
Male prevalence is noted in cases of ureteral obstruction.
What is the significance of fetal bladder visualization?
It can help in diagnosing renal agenesis and oligohydramnios.
No evidence of fetal bladder may indicate bilateral agenesis.
What is associated with echogenic solid renal mass? 4
- Adrenal hemorrhage associated with cardiac
- Genitourinary
- Gastrointestinal
- Chromosomal abnormalities.
What does the umbilical cord entering a mass indicate?
Higher risk for fetal body wall abnormalities.
What does the defect in fetal body wall abnormalities involve?
All layers of the fetal sac.
What are the characteristics of the protruding mass?
Solid or calcified mass protruding from the posterior wall of the sacrum.
What may be observed in bowel loops in cases of fetal body wall abnormalities?
Bowel loops may be thick and dilated.
What are the types of components in fetal body wall abnormalities? 3
- Predominantly external, with significant intrapelvic component.
- Predominantly internal, with polyhydramnios.
- Entirely internal, with possible increase in AFP level.
What is the male prevalence ratio for fetal body wall abnormalities?
4:1 male prevalence.
What is the fetal position?
80% of cases show a normal cord insertion.
Achondroplasia rarely invloves what? What is this condition?
Rarely contains omentum or bowel. Abnormal cartilage deposits at the long bone epiphysis.
Osteogenesis imperfecta is how common?
Most common form of skeletal dysplasia. It is autosomal dominant.
What indicates growth restriction in skeletal abnormalities?
Femur length 2 standard deviations below the mean for gestational age raises concern.
What are the sonographic findings of Achondrogenesis? 5
- Failure of ossification
- Severe micromelia
- Bowing of long bones
- Lethal short limb dysplasia
- Short trunk.
What are the characteristics of Type Ib Achondrogenesis (Parenti-Fraccaro)? 4
- Protruding abdomen
- Poor vertebral and cranial ossifications
- Thin ribs
- Small pelvis.
What are the characteristics of Type I Achondrogenesis (Langer-Saldino)?
Autosomal dominant with hypoplastic thorax and ventriculomegaly.
What is the developmental defect associated with clubfoot?
Forefoot is oriented in the same plane as the lower leg, with an abnormal relationship to the tarsal.
Osteogenesis imperfecta is a what kind of disorder? What does it lead to?
Disorder of collagen Type I production leading to brittle bones.
What is a common feature of Achondroplasia?
Bowing of long bones with normal mobility of the fetal foot.
What is the normal size of the head in sonography?
Head is of normal size
What type of HIV is most lethal?
Type II is most lethal
What may demonstrate fracture in sonography?
Abnormal limb of shape may not
May demonstrate fracture
What is a characteristic of a rocker bottom foot?
Prominent heel and convex sole
What chromosomal abnormality is associated with Trisomy 18?
Other abnormalities and fetal syndromes
What is a lethal skeletal dysplasia?
Thanatophoric dysplasia
What are the features of Type III skeletal dysplasia?
Occasional rib fractures and depressed nasal bridge
What is a common feature of male dominance in skeletal dysplasia?
Bowing of limbs and cloverleaf skull deformity
Thin cranium is associated with which skeletal dysplasia?
Associated with Type III skeletal dysplasia
