OB/GYN Quiz 1

Which fetal brain structure contains the choroid plexus and is measured at the atrium for ventriculomegaly assessment?

A. Third ventricle

B. Fourth ventricle

C. Lateral ventricle

D. Cisterna magna

C

The atrium of the lateral ventricle is considered abnormal when measuring:

A. Greater than 5 mm

B. Greater than 8 mm

C. Greater than 10 mm

D. Greater than 15 mm

Answer: C

A fetus demonstrates ventricles measuring 16 mm with thinning of the cerebral cortex. Which diagnosis is MOST appropriate?

A. Mild ventriculomegaly

B. Borderline ventriculomegaly

C. Severe ventriculomegaly

D. Normal variant

Answer: C

The dangling choroid sign occurs because the:

A. Choroid plexus becomes calcified

B. Ventricles enlarge around the choroid plexus

C. Falx cerebri is absent

D. Cerebellum herniates inferiorly

Answer: B

Communicating hydrocephalus is BEST described as:

A. Obstruction of the aqueduct of Sylvius

B. Failure of CSF reabsorption into venous circulation

C. Complete absence of the cerebral hemispheres

D. Fusion of the frontal lobes

Answer: B

Which condition is the MOST common cause of noncommunicating hydrocephalus?

A. Dandy-Walker malformation

B. Aqueductal stenosis

C. Arnold-Chiari malformation

D. Holoprosencephaly

Answer: B

A fetus demonstrates nearly absent cerebral hemispheres with preservation of the falx. Which finding BEST supports hydranencephaly rather than alobar holoprosencephaly?

A. Monoventricle

B. Fused thalami

C. Intact falx cerebri

D. Cyclopia

Answer: C

Which sonographic feature is MOST characteristic of hydranencephaly? A. Enlarged posterior fossa

B. Absent cerebellar vermis

C. Fluid replacing cerebral hemispheres

D. Thickened nuchal fold

Answer: C

Failure of the prosencephalon to divide into two cerebral hemispheres results in:

A. Dandy-Walker syndrome

B. Holoprosencephaly

C. Schizencephaly

D. Hydranencephaly

Answer: B

A fetus with cyclopia and a monoventricle MOST likely has:

A. Semilobar holoprosencephaly

B. Alobar holoprosencephaly

C. Lobar holoprosencephaly

D. Schizencephaly

Answer: B

Which chromosomal abnormality has the STRONGEST association with holoprosencephaly?

A. Trisomy 21

B. Trisomy 18

C. Trisomy 13

D. Turner syndrome

Answer: C

Dandy-Walker malformation is characterized by enlargement of the:

A. Frontal horns

B. Cavum septi pellucidi

C. Posterior fossa

D. Lateral ventricles only

Answer: C

Which structure is absent or hypoplastic in Dandy-Walker malformation?

A. Corpus callosum

B. Cerebellar vermis

C. Falx cerebri

D. Choroid plexus

Answer: B

Choroid plexus cysts are MOST commonly identified during which gestational period?

A. First trimester

B. Around 16 weeks

C. Third trimester

D. Post-term pregnancy

Answer: B

An isolated choroid plexus cyst without additional abnormalities MOST commonly:

A. Progresses to hydrocephalus

B. Persists until delivery

C. Resolves spontaneously by 26 weeks

D. Causes ventriculomegaly

Answer: C

Which associated finding would MOST concern the sonographer when a choroid plexus cyst is identified?

A. Mild polyhydramnios

B. Clenched hands

C. Single umbilical artery

D. Thick placenta

Answer: B

Microcephaly is defined as a fetal head measurement how far below normal?

A. 1 standard deviation

B. 2-3 standard deviations

C. 4-5 standard deviations

D. 6 standard deviations

Answer: B

A fetus with microcephaly would MOST likely demonstrate which biometric relationship?

A. Increased abdominal/head ratio

B. Increased femur/head ratio

C. Decreased abdominal/head ratio

D. Enlarged thoracic circumference

Answer: C

Which congenital infection is strongly linked with fetal microcephaly?

A. Cytomegalovirus

B. Rubella

C. Zika virus

D. Syphilis

Answer: C

Gray matter clefts extending from the ventricle to the meninges are diagnostic for:

A. Porencephaly

B. Schizencephaly

C. Holoprosencephaly

D. Dandy-Walker syndrome

Answer: B

Which structure is commonly absent in schizencephaly?

A. Cerebellar vermis

B. Cisterna magna

C. Cavum septi pellucidi

D. Falx cerebri

Answer: C

A cystic midline intracranial structure demonstrating turbulent vascular flow on color Doppler is MOST suspicious for:

A. Arachnoid cyst

B. Dandy-Walker cyst

C. Vein of Galen aneurysm

D. Porencephalic cyst

Answer: C

The MOST serious fetal complication associated with Vein of Galen aneurysm is:

A. Pulmonary hypoplasia

B. High-output cardiac failure

C. Renal agenesis

D. Duodenal atresia

Answer: B

Polyhydramnios is MOST associated with which fetal GI anomaly?

A. Imperforate anus

B. Jejunal stenosis

C. Esophageal atresia

D. Renal agenesis

Answer: C

Oligohydramnios is MOST commonly associated with:

A. Duodenal atresia

B. Fetal urinary tract abnormalities

C. Maternal diabetes

D. Anencephaly

Answer: B

The lemon sign in spina bifida refers to:

A. Compression of the cerebellum

B. Concavity of the frontal bones

C. Enlargement of the occipital horns

D. Flattening of the facial profile

Answer: B

The banana sign occurs secondary to:

A. Enlarged ventricles

B. Inferior displacement of the cerebellum

C. Fusion of the thalami

D. Enlarged posterior fossa

Answer: B

A fetal spine demonstrating a "U" shaped posterior ossification pattern in transverse view is MOST consistent with:

A. Hemivertebrae

B. Scoliosis

C. Spina bifida

D. Sacral agenesis

Answer: C

Myelomeningocele differs from meningocele because it contains:

A. CSF only

B. Meninges only

C. Neural tissue and meninges

D. Bone and meninges

Answer: C

Which condition is MOST strongly associated with Chiari II malformation?

A. Dandy-Walker syndrome

B. Myelomeningocele

C. Holoprosencephaly

D. Hydranencephaly

Answer: B

Anencephaly results from failure of closure of the neural tube at the:

A. Caudal end on day 27

B. Rostral end on day 25

C. Midline on day 30

D. Posterior neuropore on day 35

Answer: B

Which sonographic feature BEST distinguishes exencephaly from anencephaly?

A. Enlarged ventricles

B. Presence of cerebral hemispheres without calvarium

C. Absent falx cerebri

D. Enlarged cisterna magna

Answer: B

An occipital calvarial defect with herniated brain tissue is termed:

A. Cephalocele

B. Encephalocele

C. Meningocele

D. Hydranencephaly

Answer: B

Which syndrome is classically associated with occipital encephalocele, enlarged polycystic kidneys, and postaxial polydactyly?

A. Edwards syndrome

B. Turner syndrome

C. Meckel-Gruber syndrome

D. Patau syndrome

Answer: C

The "stargazer" appearance is MOST characteristic of:

A. Iniencephaly

B. Exencephaly

C. Dandy-Walker malformation

D. Chiari II malformation

Answer: A

Which finding is MOST commonly associated with trisomy 18?

A. Holoprosencephaly

B. Clenched hands

C. Polydactyly

D. Cyclopia

Answer: B

Which abnormality is MOST associated with trisomy 13?

A. Strawberry skull

B. Choroid plexus cysts

C. Holoprosencephaly

D. Rocker-bottom feet

Answer: C

Maternal diabetes significantly increases the risk for:

A. Neural tube defects

B. Turner syndrome

C. Holoprosencephaly only

D. Dandy-Walker malformation only

Answer: A

Macrosomia secondary to maternal diabetes commonly demonstrates: A. Small cheeks and thin skin

B. Skin thickening and enlarged cheeks

C. Oligohydramnios and growth restriction

D. Absent subcutaneous fat

Answer: B

Pregnancy-induced hypertension with seizures is termed:

A. HELLP syndrome

B. Gestational hypertension

C. Eclampsia

D. Chronic hypertension

Answer: C

Which finding is part of the classic TORCH infection spectrum?

A. Intracranial calcifications

B. Pulmonary sequestration

C. Cloacal exstrophy

D. Duodenal atresia

Answer: A

The quad marker screening test includes all of the following EXCEPT:

A. AFP

B. Estriol

C. Beta-hCG

D. Progesterone

Answer: D

Elevated maternal serum AFP is MOST associated with:

A. Trisomy 21

B. Open neural tube defects

C. Trisomy 18

D. Turner syndrome

Answer: B

Reduced estriol levels are MOST strongly associated with:

A. Trisomy 18

B. Polyhydramnios

C. Duodenal atresia

D. Macrosomia

Answer: A

Which prenatal diagnostic procedure is typically performed FIRST?

A. Amniocentesis

B. CVS

C. Cordocentesis

D. Fetoscopy

Answer: B

CVS is usually performed between:

A. 6-8 weeks

B. 10-14 weeks

C. 15-18 weeks

D. 20-24 weeks

Answer: B

Amniocentesis for genetic testing is MOST commonly performed between:

A. 8-10 weeks

B. 10-12 weeks

C. 15-18 weeks

D. 28-32 weeks

Answer: C

Compared with amniocentesis, CVS has:

A. Lower miscarriage risk

B. No risk of limb defects

C. Earlier diagnosis capability

D. Better lung maturity assessment

Answer: C

Which fetal ventricular landmark is measured in the axial transventricular plane to evaluate for ventriculomegaly?

A. Frontal horn

B. Atrium of the lateral ventricle

C. Third ventricle

D. Cavum septi pellucidi

Answer: B

The normal atrial width of the lateral ventricle should remain relatively constant after:

A. 10 weeks

B. 15 weeks

C. 20 weeks

D. 28 weeks

Answer: B

A fetus with mild ventriculomegaly should be carefully evaluated for all of the following EXCEPT:

A. Aneuploidy

B. CNS anomalies

C. Congenital infection

D. Placenta previa

Answer: D

Obstruction of the aqueduct of Sylvius leads to enlargement of the:

A. Third and lateral ventricles only

B. Fourth ventricle only

C. Cisterna magna only

D. Posterior fossa only

Answer: A

Which condition would MOST likely produce communicating hydrocephalus?

A. Aqueductal stenosis

B. Arnold-Chiari II malformation

C. Impaired arachnoid villi absorption

D. Dandy-Walker malformation

Answer: C

A fetus demonstrates absent cerebral cortex with preserved falx and thalami. Which diagnosis is MOST likely?

A. Severe hydrocephalus

B. Alobar holoprosencephaly

C. Hydranencephaly

D. Schizencephaly

Answer: C

Which sonographic finding favors alobar holoprosencephaly over hydranencephaly?

A. Preserved falx cerebri

B. Presence of fused thalami

C. Absence of cerebral hemispheres

D. Large fluid-filled cranial cavity

Answer: B

Semilobar holoprosencephaly is characterized by:

A. Complete hemispheric separation

B. Partial posterior hemispheric separation

C. Complete absence of the falx

D. Normal ventricular anatomy

Answer: B

Cyclopia is MOST strongly associated with:

A. Dandy-Walker syndrome

B. Schizencephaly

C. Alobar holoprosencephaly

D. Vein of Galen aneurysm

Answer: C

Which posterior fossa abnormality demonstrates cystic dilation of the fourth ventricle with enlarged posterior fossa?

A. Blake pouch cyst

B. Arachnoid cyst

C. Dandy-Walker malformation

D. Mega cisterna magna

Answer: C

A normal cerebellar vermis helps exclude:

A. Choroid plexus cysts

B. Dandy-Walker malformation

C. Vein of Galen aneurysm

D. Hydrocephalus

Answer: B

Bilateral choroid plexus cysts are considered a soft marker for:

A. Trisomy 21

B. Turner syndrome

C. Trisomy 18

D. Triploidy

Answer: C

Which finding alongside choroid plexus cysts MOST increases suspicion for Edwards syndrome?

A. Echogenic intracardiac focus

B. Omphalocele

C. Mild pyelectasis

D. Short humerus only

Answer: B

A fetus with a sloping forehead and disproportionately small head MOST likely demonstrates:

A. Hydrocephalus

B. Macrocephaly

C. Microcephaly

D. Dolichocephaly

Answer: C

Which TORCH infection is classically associated with intracranial calcifications and ventriculomegaly?

A. Cytomegalovirus

B. Varicella

C. Rubella

D. Syphilis

Answer: A

Schizencephaly differs from porencephaly because schizencephalic clefts are lined by:

A. White matter

B. CSF only

C. Gray matter

D. Choroid plexus

Answer: C

Which intracranial vascular anomaly may mimic a cystic mass on grayscale imaging?

A. Arachnoid cyst

B. Vein of Galen aneurysm

C. Porencephalic cyst

D. Choroid plexus cyst

Answer: B

Polyhydramnios develops in esophageal atresia because the fetus cannot:

A. Produce urine

B. Swallow amniotic fluid normally

C. Absorb CSF

D. Empty the bladder

Answer: B

Which condition is MOST likely associated with severe oligohydramnios during the second trimester?

A. Bilateral renal agenesis

B. Duodenal atresia

C. Maternal diabetes

D. Trisomy 21

Answer: A

A "V" shaped configuration of the posterior spinal ossification centers is MOST suspicious for:

A. Sacral agenesis

B. Spina bifida

C. Kyphosis

D. Hemivertebrae

Answer: B

The lemon sign is caused by:

A. Ventricular dilation

B. Increased intracranial pressure

C. Frontal bone scalloping

D. Enlargement of the cerebellum

Answer: C

Chiari II malformation involves downward displacement of the:

A. Frontal lobes

B. Cerebellum and brainstem

C. Temporal lobes

D. Corpus callosum

Answer: B

Which neural tube defect is considered the MOST severe form of spina bifida?

A. Spina bifida occulta

B. Meningocele

C. Myelomeningocele

D. Rachischisis

Answer: D

A tuft of hair over the lumbosacral spine is a classic sign of:

A. Myelomeningocele

B. Rachischisis

C. Spina bifida occulta

D. Iniencephaly

Answer: C

Anencephaly results from failed closure of the:

A. Posterior neuropore

B. Anterior neuropore

C. Neural crest

D. Mesencephalon

Answer: B

Which fetal structure may still be present in anencephaly?

A. Cerebral hemispheres

B. Lateral ventricles

C. Brainstem

D. Corpus callosum

Answer: C

Exencephaly is considered the embryologic precursor to:

A. Dandy-Walker syndrome

B. Holoprosencephaly

C. Anencephaly

D. Schizencephaly

Answer: C

An occipital encephalocele is MOST commonly associated with:

A. Meckel-Gruber syndrome

B. Turner syndrome

C. Down syndrome

D. Achondroplasia

Answer: A

Which syndrome classically demonstrates the triad of occipital encephalocele, enlarged polycystic kidneys, and polydactyly?

A. Patau syndrome

B. Edwards syndrome

C. Meckel-Gruber syndrome

D. Pierre Robin syndrome

Answer: C

The "stargazer fetus" appearance is due to severe:

A. Thoracic scoliosis

B. Cervical hyperextension

C. Macrocephaly

D. Ventriculomegaly

Answer: B

Which abnormality is commonly associated with iniencephaly?

A. Pulmonary hypoplasia

B. Bilateral renal agenesis

C. Tricuspid atresia

D. Duodenal atresia

Answer: A

Patau syndrome is synonymous with:

A. Trisomy 21

B. Trisomy 18

C. Trisomy 13

D. Monosomy X

Answer: C

Holoprosencephaly, cleft lip/palate, and polydactyly are strongly associated with:

A. Edwards syndrome

B. Turner syndrome

C. Patau syndrome

D. Down syndrome

Answer: C

Edwards syndrome is the:

A. Most common trisomy overall

B. Second most common chromosomal trisomy

C. Least survivable trisomy

D. Only trisomy associated with CPCs

Answer: B

Which fetal hand position is classically associated with trisomy 18?

A. Open hands with clinodactyly

B. Polydactylous hands

C. Clenched hands with overlapping digits

D. Syndactyly

Answer: C

Maternal diabetes is associated with increased risk of all of the following EXCEPT:

A. Anencephaly

B. Clubfoot

C. Two-vessel cord

D. Bilateral renal agenesis

Answer: D

Macrosomic fetuses commonly demonstrate:

A. Growth restriction

B. Thickened abdominal subcutaneous tissue

C. Small abdominal circumference

D. Oligohydramnios

Answer: B

Pregnancy-induced hypertension that resolves after delivery is also known as:

A. Chronic hypertension

B. Toxemia

C. Gestational trophoblastic disease

D. Diabetes insipidus

Answer: B

Which condition is characterized by hypertension, proteinuria, edema, and CNS irritability?

A. Chronic hypertension

B. Eclampsia

C. Preeclampsia

D. HELLP syndrome only

Answer: C

Which TORCH infection is associated with fetal ascites and cardiomyopathy in the lecture?

A. Toxoplasmosis

B. Herpes simplex

C. Rubella

D. Syphilis

Answer: A

Parvovirus B19 infection may lead to fetal:

A. Holoprosencephaly

B. Hydrops fetalis

C. Duodenal atresia

D. Dandy-Walker malformation

Answer: B

Elevated maternal serum AFP is expected in:

A. Closed neural tube defects

B. Open neural tube defects

C. Trisomy 21 only

D. Turner syndrome

Answer: B

Which condition may falsely elevate maternal AFP levels?

A. Incorrect gestational dating

B. Maternal hypotension

C. Placenta accreta

D. Oligohydramnios

Answer: A

The quad screen is MOST commonly performed during the:

A. First trimester

B. Early second trimester

C. Third trimester

D. Intrapartum period

Answer: B

Compared with amniocentesis, CVS does NOT evaluate:

A. Karyotype

B. Genetic abnormalities

C. Neural tube defects through AFP

D. Chromosomal abnormalities

Answer: C

Amniocentesis samples:

A. Placental villi

B. Umbilical cord blood

C. Amniotic fluid

D. Fetal liver tissue

Answer: C