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6 Congenital abnormalities Questions
and Answers (100% Correct Answers)
Already Graded A+
What is a targeted ultrasound? Ans: A specialized sonographic
survey of a fetus at risk for specific congenital anomalies
based on family history or a diagnosed fetal anomaly.
© 2026 Assignment
What are the main objectives of targeted surveys? Ans: To
detect or confirm a congenital anomaly, assess the fetus at risk
for a fetal anomaly, and clinically follow the progression of a
Guru01 - Stuvia
congenital anomaly during gestation.
Expert
What are some clinical indications for a targeted ultrasound?
Ans: Family history of congenital anomalies, suspected
congenital anomalies, history of chromosomal abnormalities,
abnormal fetal surveys, high-risk pregnancies, and chemical or
drug exposure.
What is anencephaly? Ans: A failure of the rostral neuropore to
close, resulting in partial formation of the forebrain and
leaving only the brain stem, midbrain, and skull base.
What are the sonographic findings of anencephaly? Ans:
Absent skull or brain above the orbits, rudimentary brain
tissue herniating from the defect, bulging fetal orbits, and
polyhydramnios in approximately half of cases after 26 weeks.
What causes anencephaly? Ans: Increased risk in patients with
diabetes, environmental factors, teratogenic insults, and
amniotic band syndrome.
What is acrania (exencephaly)? Ans: A lethal anomaly where
mesenchymal tissue fails to migrate, preventing bone
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formation over cerebral tissue, resulting in an absent fetal
cranium but present brain tissue.
What are the sonographic findings of acrania? Ans:
Development of brain tissue without calvarium, disorganized
brain tissue, and prominent sulcal markings.
What is encephalocele? Ans: A neural tube defect caused by
herniation of the brain through a defect in the skull, most
commonly involving the occipital bone.
© 2026 Assignment
What are the sonographic findings of encephalocele? Ans: An
extracranial mass, ventriculomegaly, and a bony defect in the
Guru01 - Stuvia
skull.
Expert
What is microcephaly? Ans: An abnormally small head due to a
reduction in brain size, often associated with developmental
defects.
What are some causes of microcephaly? Ans: Inheritance,
chromosomal aberrations, severe prenatal radiation, viral
infections, maternal substance abuse, and mercury poisoning.
What is ventriculomegaly? Ans: Dilation of the ventricles
within the brain due to obstruction of cerebrospinal fluid flow,
potentially leading to brain damage.
What are common causes of ventriculomegaly? Ans: Neural
tube defects, encephaloceles, Dandy-Walker malformations,
agenesis of the corpus callosum, and aqueductal stenosis.
What are the sonographic findings of ventriculomegaly? Ans:
Lateral ventricle enlargement exceeding 10mm, a dangling
choroid plexus, and possible dilation of the 3rd and 4th
ventricles.
6 Congenital abnormalities Questions
and Answers (100% Correct Answers)
Already Graded A+
What is a targeted ultrasound? Ans: A specialized sonographic
survey of a fetus at risk for specific congenital anomalies
based on family history or a diagnosed fetal anomaly.
© 2026 Assignment
What are the main objectives of targeted surveys? Ans: To
detect or confirm a congenital anomaly, assess the fetus at risk
for a fetal anomaly, and clinically follow the progression of a
Guru01 - Stuvia
congenital anomaly during gestation.
Expert
What are some clinical indications for a targeted ultrasound?
Ans: Family history of congenital anomalies, suspected
congenital anomalies, history of chromosomal abnormalities,
abnormal fetal surveys, high-risk pregnancies, and chemical or
drug exposure.
What is anencephaly? Ans: A failure of the rostral neuropore to
close, resulting in partial formation of the forebrain and
leaving only the brain stem, midbrain, and skull base.
What are the sonographic findings of anencephaly? Ans:
Absent skull or brain above the orbits, rudimentary brain
tissue herniating from the defect, bulging fetal orbits, and
polyhydramnios in approximately half of cases after 26 weeks.
What causes anencephaly? Ans: Increased risk in patients with
diabetes, environmental factors, teratogenic insults, and
amniotic band syndrome.
What is acrania (exencephaly)? Ans: A lethal anomaly where
mesenchymal tissue fails to migrate, preventing bone
, 2
formation over cerebral tissue, resulting in an absent fetal
cranium but present brain tissue.
What are the sonographic findings of acrania? Ans:
Development of brain tissue without calvarium, disorganized
brain tissue, and prominent sulcal markings.
What is encephalocele? Ans: A neural tube defect caused by
herniation of the brain through a defect in the skull, most
commonly involving the occipital bone.
© 2026 Assignment
What are the sonographic findings of encephalocele? Ans: An
extracranial mass, ventriculomegaly, and a bony defect in the
Guru01 - Stuvia
skull.
Expert
What is microcephaly? Ans: An abnormally small head due to a
reduction in brain size, often associated with developmental
defects.
What are some causes of microcephaly? Ans: Inheritance,
chromosomal aberrations, severe prenatal radiation, viral
infections, maternal substance abuse, and mercury poisoning.
What is ventriculomegaly? Ans: Dilation of the ventricles
within the brain due to obstruction of cerebrospinal fluid flow,
potentially leading to brain damage.
What are common causes of ventriculomegaly? Ans: Neural
tube defects, encephaloceles, Dandy-Walker malformations,
agenesis of the corpus callosum, and aqueductal stenosis.
What are the sonographic findings of ventriculomegaly? Ans:
Lateral ventricle enlargement exceeding 10mm, a dangling
choroid plexus, and possible dilation of the 3rd and 4th
ventricles.
