2nd/3rd Trimester Pathology 37%

Question 1

A trident hand is commonly seen with which skeletal abnormality?

a. spina bifida aperta
b. spina bifida occulta
c. heterozygous achondroplasia
d. osteogenesis imperfecta II

Answer 1

C
A trident hand is commonly seen with heterozygous achondroplasia. It is demonstrated as an excessive gap between the 3rd and 4th digits of the hand.

Question 2

A patient presents for her first ultrasound at 22 weeks. A twin pregnancy with a single placenta is identified. Fetus A demonstrates an increased C/T ratio, mild pleural effusion and anasarca. No cardiac activity can be identified in fetus B. There are also no obvious cranial or cerebral structures. These findings are most suggestive of:

a. Vanishing twin syndrome
b. twin reversed arterial perfusion sequence
c. Dichorionic/diamniotic twins
d. Fetus A - hydrops, Fetus B - Triploidy

Answer 2

B
Twin Reversed Arterial Perfusion Sequence (TRAP Syndrome) is also referred to as a Parabiotic Twin or Acardiac twin. It is considered the most severe form of a twin to twin transfusion. It occurs in monochorionic pregnancies with a shared placenta. The umbilical arteries and vein of the donor twin on the surface of the placenta. There is an AV malformation with the umbilical artery to artery shunt and venous to venous shunt from “normal” donor twin. The acardiac twin has no connection to the placenta for fully oxygenated arterial circulation. The normal twin or “pump twin” eventually develops heart failure due to increased load and can also develop hydrops. The acardiac twin has no cardiac structure or limited structures with no motion and multiple other abnormalities. The acardiac twin also usually has missing and unrecognizable features and it only develops a trunk and partial lower extremities due to lack of oxygenated blood.

Question 3

A patient presents at 20 weeks with their size measuring 12 days behind where they should be according to their first trimester US. The cranial bones appear less echogenic and the humerus and femur appear slightly bowed. The small bones in the extremities are also somewhat difficult to identify due to decreased echogenicity. These findings are most suggestive of:

a. Thanantophoric dwarfism
b. Osteogenesis imperfecta
c. Achondroplasia
d. IUGR

Answer 3

B
Osteogenesis imperfecta causes brittle bone formations that can be fatal during birth. All fetal bones are less dense and fracture very easily. It can be diagnosed as early as 15 weeks and ruled out if bony structures appear normal after 17 weeks.

Question 4

Which of the following is not an expected post-partum complication?

a. hemorrhage
b. Metritis
c. Thrombosis/Embolism
d. Gestational diabetes

Answer 4

D

Gestational diabetes presents during the pregnancy and may persist as diabetes mellitus post-partum.

Question 5

What is the most common cause for a shift of cardiac axis/position?

a. congenital cystic adenomatoid malformation
b. ectopia cordis
c. chromosomal anomalies
d. diaphragmatic hernia

Answer 5

D

A diaphragmatic hernia is the most common reason for shift of cardiac axis/position.

Question 6

In a 32 week pregnancy, a cervix that is less than ______ in length and dilated more than ______ is considered incompetent.

a. 2cm, 2cm
b. 4cm, 2cm
c. 3cm, 3 cm
d. 3cm, 2cm

Answer 6

D

A cervix <3cm in length is abnormal before 34 weeks. A cervix that is dilated more than 2cm is considered incompetent.

Question 7

Esophageal atresia is a significant indication for which of the following Trisomies?

a. 13
b. 18
c. 20
d. 21

Answer 7

B
Edward syndrome is a lethal fetal abnormality because it is commonly associated with numerous congenital defects including: Renal Agenesis, IUGR, ACC/Holoprosencephaly, Cardiac defects, Digestive atresia (esophageal commonly seen), Omphalocele, Single umbilical artery, Clinodactyly or clenched hands, and Facial defects.

Question 8

What urinary anomaly usually affects one kidney, but can lead to bilateral renal enlargement due to contralateral renal compensation?

a. Potter syndrome
b. multicystic kidney disease
c. adult PCKD
d. infantile PCKD

Answer 8

B
Multicystic kidney disease is usually unilateral because it is caused by obstruction early in the pregnancy. The unaffected kidney may enlarge because it takes over the function for the damaged kidney.

Question 9

You are performing a 4 week follow up on twins that should be 14 weeks. On today’s exam there is only a single normal fetus present and an irregular anechoic area adjacent to the normal sac. The patient has not experienced any bleeding. What most likely explains these findings?

a. vanishing twin syndrome
b. stuck twin syndrome
c. twin to twin transfusion
d. parabiotic twin

Answer 9

A
Vanishing Twin Syndrome:

Embryonic demise of one fetus is a multiple pregnancy; occurs later in the 1st trimester or in the first few weeks of the 2nd trimester; Failure of sac growth or a sac with irregular contour and margination; Remaining twin is usually not affected as the other fetus is resorbed.

Question 10

Which of the following is most suggestive of holoprosencephaly?

a. bilateral cleft palate
b. bilateral cleft lip
c. cebocephaly
d. prominent falx cerebri

Answer 10

C
Cebocephaly is a midline facial defect that consists of hypotelorism and a nose with a single nostril. It is associated with holoprosencephaly, which usually has related midline facial defects. A bilateral, or left and right side, cleft palate is not a midline defect. The falx cerebri is partially or completely absent in holoprosencephaly.

Question 11

What is the most common congenital cardiac anomaly?

a. patent ductus arteriosus
b. Tetralogy of Fallot
c. ventricular septal defect
d. atrial septal defect

Answer 11

C

The VSD is the most commonly occurring congenital cardiac defect.

Question 12

In twin to twin transfusion syndrome (TTTS) the donor twin demonstrates _________ and in twin reversed atrial perfusion sequence (TRAP) the donor twin demonstrates ________.

a. congestive heart failure, no cardiac structure
b. polyhydramnios, oligohydramnios
c. pleural effusion, ascites
d. growth restriction, hydrops

Answer 12

D
Twin-to-Twin Transfusion - AV malformations in placenta shunts blood from one twin to the other twin. The donor twin supplies the recipient with oxygenated blood. This causes the donor twin to appear growth restricted with oligohydramnios. It can appear stuck to the uterine wall AKA Stuck Twin Syndrome. The recipient twin will develop hydrops and heart failure, polyhydramnios due to increased arterial inflow from the placenta.
Twin reversed arterial perfusion sequence occurs when there is an AV malfomation on the surface of the placenta. There is a normal fetus and an acardiac twin without a fetal heart to pump blood. The umbilical arteries of the normal twin are connected to those of the acardiac twin. Blood moves from the placenta, to the normal twin, back to the anastomoses and into the acardiac twin. Very little oxygen reaches the acardiac twin and there is usually no development of the head and upper body. Typically, a trunk with no legs forms. The normal twin develops heart failure and hydrops due to the increased flow responsibilities for both fetuses.

Question 13

A patient presents for a fetal anatomy scan at 26 weeks. The head circumference, biparietal diameter and the femur length measure 25 weeks. The abdominal circumference measures 28.5 weeks. Which of the following could cause this discrepancy?

a. symmetric IUGR
b. hydrops
c. hepatic mesenchymal hamartoma
d. asymmetric IUGR

Answer 13

C
A tumor of the liver can lead to an abnormal abdominal circumference while other biometric measurements are normal. A mesenchymal hamartoma is a benign tumor of the liver. It appears as an irregular hypoechoic mass with internal cystic components. These tumors can grow very large and displace other organs.

Question 14

Which of the following is true regarding autosomal dominant polycystic kidney disease?

a. if it occurs in a fetus, at least one parent has ADPKD
b. it is usually fatal soon after birth
c. it usually occurs unilaterally
d. it is usually associated with polyhydramnions

Answer 14

A
If the mother has an autosomal dominant disorder and the father is normal, there is a 50% chance that the fetus will have the disorder. It all depends on if the fetus receives the normal gene or abnormal gene from the mother.

Question 15

You are performing a follow up exam for limited fetal anatomy of the last US with non-visualization of the stomach and kidneys at 15 weeks. The fetus should be 21 weeks today. You identify two normal kidneys but the stomach is barely visible and very small. Borderline polyhydramnios is also present. These findings are most suggestive of:

a. anal atresia
b. situs inversus
c. trisomy 21
d. esophageal atresia

Answer 15

D
A small or non-visualized stomach on serial exams can indicate esophageal atresia or any other reason that the fetus cannot swallow fluid.

Question 16

Macrosomia describes a fetus weighing more than:

a. 4000g
b. 2000g
c. 10lbs
d. 3000g

Answer 16

A

Macrosomia describes a fetus weighing more than 4000g.

Question 17

Hypoplasia of the ________ is a soft marker of Trisomy 21.

a. middle phalanx of the 5th digit
b. distal phalanx of the 5th digit
c. distal phalanx of the 3rd digit
d. middle phalanx of the 3rd digit

Answer 17

A

Hypoplasia of the middle phalanx of the 5th digit is a soft marker of Trisomy 21.

Question 18

All of the following can cause a false positive diagnosis of club foot, except:

a. oligohydramnios
b. uncooperative fetus
c. footling breech position
d. 8cm intramural fibroid

Answer 18

B
Extrinsic compression of the fetal extremity and low fluid levels can cause the normal foot/ankle to lie in an abnormal position in the uterus which gives the appearance of club foot. When diagnosing club foot, it is important to see the deformity in multiple views with different positions of the extremity. An abnormality should never be diagnosed if the views are suboptimal from an uncooperative fetus. If club foot is suspected and the fetus is not cooperating to allow appropriate imaging of the foot/ankle, reschedule them for focused follow up exam.

Question 19

Hydranencephaly is caused by:

a. obstruction of the umbilical arteries that leads to a backlog of fetal blood in the brain
b. obstruction of the internal carotid artery that leads to cerebral tissue destruction
c. fetal head trauma due to excessive extra-uterine pressure
d. obstruction of the umbilical vein that leads to a backlog of fetal blood in the brain

Answer 19

B
Hydranencephaly is the destruction of cerebral tissue during fetal development. It usually leads to cognitive and development. It usually leads to cognitive and developmental issues. Causes include ICA/MCA occlusion, maternal infection, carbon monoxide exposure.

Question 20

Which anomaly is almost always associated with a tracheoesophageal fistula?

a. Bochdalek hernia
b. esophageal atresia
c. megacystitis
d. duodenal atresia

Answer 20

B
Esophageal atresia refers to the absence of esophageal opening into the stomach. Most cases have an associated tracheoesophageal fistula that allows some fluid to enter the digestive system through the fistula. Small stomach visualized on US exam.

Question 21

A maternal history of hyperparathyroidism or hypothyroidism will usually have what effect on the fetus?

a. no effect
b. hydrops
c. fetal demise
d. macrosomia, hepatomegaly

Answer 21

C
Women with a hormonal imbalance rarely carry a baby to term. Hyperthyroidism, hypothyroidism, hyperparathyroidism, phenylketonuria are examples of maternal hormonal disorders. IUGR and fetal demise are common findings. Cardiac anomalies are also prevalent in phenylketonuria.

Question 22

Ebstein anomaly is defined as:

a. abnormal placement of the mitral and tricuspid valves more inferiorly into the apex of the ventricles
b. abnormal placement of the mitral valve more inferiorly into the apex of the left ventricle
c. abnormal placement of the tricuspid valve more inferiorly into the apex of the right ventricle
d. abnormal placement of the tricuspid valve more inferiorly into the apex of the left ventricle

Answer 22

C
Ebstein anomaly refers to abnormal placement of the tricuspid valve more inferior in the apex of the right ventricle. This causes an enlarged right atrium and small right ventricle.

Question 23

While performing a scan on a 27 week fetus, you see echogenic foci in the liver and a thick walled cyst in the fetal abdomen. Several small bowel loops appear dilated with limited peristalsis. Fetal ascites and polyhydramnios are also present. These findings are most consistent with:

a. umbilical cord knot
b. duodenal atresia
c. meconium peritonitis
d. trisomy 21

Answer 23

C
Meconium Peritonitis is usually associated with fetal bowel obstruction and perforation. Pseudocysts form to try to wall off the bowel contents.

Question 24

What is the most common abnormality of the umbilical cord?

a. single artery
b. cord varix
c. cord cyst
d. cord knot

Answer 24

A

An umbilical cord with a single artery is the most common anomaly of the cord.

Question 25

If you identify hypoplastic left heart in a female fetus, what fetal syndrome should be suspected?

a. Turner
b. Noonan
c. Edwards
d. Triploidy

Answer 25

A
Turner syndrome is the most common syndrome seen with HLHS. The fact that the fetus is female further supports the possibility of Turner syndrome.

Question 26

A circumvallate placenta:

a. is caused by back folding of the placenta and fetal membranes towards the chorionic surface
b. causes placental thickening associated with fetal hydrops
c. causes placental insufficiency and IUGR
d. is commonly associated with chromosomal anomalies

Answer 26

A
A circumvallate placenta appears as rolled or curled placental edges. It is caused by back folding of the placenta and fetal membranes towards the chorionic surface. There is an increased risk of abruption or spontaneous abortion.

Question 27

You are evaluating the heart on a 28 week fetus. A single large trunk vessel exits the heart and the pulmonary artery appears to branch from it instead of from the right ventricle. These findings describe:

a. partial anomalous pulmonary venous return
b. double outlet left ventricle
c. truncus arteriosus
d. total anomalous pulmonary venous return

Answer 27

C
Truncus arteriosus refers to a single large outflow tract with malalignment VSD. Type 1 occurs when the pulmonary artery arises from the trunk vessel after it exits the heart. There are 4 types of truncus with type 1 being the most common.

Question 28

The most commonly reported intrauterine infection in pregnancy is:

a. cytomegalovirus
b. pelvic inflammatory disease
c. staphylococcus
d. HIV

Answer 28

A

The most commonly reported intrauterine infection in pregnancy is CMV.

Question 29

If posterior shadowing from the skull, ribs and long bones is demonstrated, which of the following abnormalities can be ruled out?

a. Ellis van Creveld syndrome
b. craniosynostosis
c. hypophosphatasia
d. arthrogryposis

Answer 29

C
Hypophosphatasia is a skeletal disorder characterized by hypomineralization. Proper ossification of the fetal skeleton can rule out the presence of the disorder. Normal fetal bones will demonstrate posterior shadowing in the 2nd/3rd trimester.

Question 30

Which of the following is the most common facial anomaly?

a. cleft lip/palate
b. micrognathia
c. hypertelorism
d. hypotelorism

Answer 30

A

Cleft lip/palate is the most common facial defect.

Question 31

Which of the following skeletal anomalies usually occurs as an isolated finding?

a. phocomelia
b. talipes equinovarus
c. rhizomelia
d. arthrogryposis

Answer 31

B
Congenital talipes equinovarus:
Affected foot appears rotated internally at the ankle with an eccentric junction between the calcaneus and tarsal bones; 50% of cases are bilateral; In most cases it is an isolated dysmelia; Can be caused by oligohydramnios, amniotic band sequence, extrinsic compression; Occurs in males more often than in females by a ratio of 2:1.

Question 32

Which of the following correctly describes the sonographic appearance of the pump twin in a twin reversed arterial perfusion sequence?

a. asymmetric IUGR with aged placenta
b. skin edema, ascites, congestive heart failure
c. symmetric IUGR with normal placenta
d. donor twin usually appears normal

Answer 32

B
The acardiac twin has no connection to the placenta for arterial/venous circulation. An umbilical artery to artery shunt and venous to venous shunt is present from the “normal” donor twin. The normal twin or “pump twin” develops heart failure due to increased load and can also develop hydrops. The prognosis is very poor for both fetuses.

Question 33

While scanning a 22 week fetus, you identify normal long bones in the lower extremities but the feet are very small with shortened tarsals and metatarsals. Which of the terms describes this isolated finding?

a. clinodactyly
b. acromelia
c. rhizomelia
d. phocomelia

Answer 33

B

Acromelia refers to the shortening of the most distal portion (hand, foot) of an extremity.

Question 34

Which of the following is NOT considered a critical finding on a fetal ultrasound exam?

a. placental abruption
b. umbilical cord knot
c. cervical pregnancy
d. circummarginate placenta

Answer 34

D
Circummarginate placenta is similar to a circumvallate placenta in that there is a ring of membranes on the fetal surface of the placenta but the ring is much thinner on the circummarginate placenta. The thin ring of membranes is of no clinical significance. The circumvallate placenta with the thick ring of membranes has an increased risk of placental abruption and premature delivery.

Question 35

Which of the following is least likely to be associated with placental abruption?

a. placental lakes
b. fibroids
c. cocaine use
d. smoking

Answer 35

A
Placental abruption can be associated with abdominal trauma, smoking, fibroids and drug use. Placental lakes are a normal finding.

Question 36

When evaluating the abdominal circumference of a 30 week fetus, you note that the umbilical vein curves to the left toward the stomach and the gallbladder is medial to the vein. The AC measurement and the skin thickness are normal. These findings are most suggestive of:

a. normal anatomy
b. persistent right umbilical vein
c. absent ductus venosus
d. situs inversus

Answer 36

B
Persistent Right Umbilical Vein occurs when the right umbilical/portal vein remains open, normally the left side remains open. In normal anatomy, the umbilical vein curves to the right toward the liver and the gallbladder is lateral to the vein. With PRUV, the umbilical vein curves to the left toward the stomach and the gallbladder is medial to the vein. If situs inversus is present, the stomach would be on the right.

Question 37

While evaluating the fetal brain of a 27 week fetus, you identify an anechoic space midline in the cerebrum. The space appears to communicate with an anechoic tubular structure coursing inferiorly. Color Doppler demonstrates low velocity, swirling flow within the structures. Which of the following describes the findings?

a. vein of Galen pseudoaneurysm
b. Dandy Walker Malformation
c. Aqueductal stenosis
d. Vein of Galen aneurysm

Answer 37

D
The Vein of Galen becomes dilated and aneurysmal due to an AV malformation in the brain. A pseudoaneurysm is a false aneurysm related to flow outside of a punctured artery. There is no flow detected by color Doppler when evaluating structures that contain cerebrospinal fluid.

Question 38

An encephalocele can easily be mistaken for _________.

a. gastroschisis
b. epignathus
c. porencephaly
d. cystic hygroma

Answer 38

D
Closely evaluate the bony structure of the cranium to differentiate a cystic hygroma from an encephalocele. The hygroma forms outside the cranium. The encephalocele occurs due to an opening in the cranium allowing the cranial membranes to herniate.

Question 39

Which of the following is the most common type of lethal fetal skeletal dysplasia?

a. homozygous achondroplasia
b. thanatophoric skeletal dysplasia
c. achondrogenesis
d. osteogenesis imperfecta type II

Answer 39

B
Thanantophoric Skeletal Dysplasia is the most common lethal skeletal dysplasia.

Features:
Autosomal dominant
Macrocrania, cloverleaf skull****
Frontal bossing
short ribs
pear or bell shaped thorax
Pulmonary hypoplasia
Polyhydramnios
Severe micromelia
Bowing of long bones

Question 40

Which trisomy is commonly associated with radial ray anomalies?

a. 13
b. 18
c. 21
d. 23

Answer 40

B
Radial ray anomalies involve abnormal radial development (hypoplasia or aplasia). This type of anomaly is associated with Trisomy 18, Holt Oram syndrome, and amniotic band sequence.

Question 41

A small, underdeveloped right ventricle, right atrium and pulmonary artery are collectively referred to as:

a. noonan syndrome
b. double outlet right ventricle
c. hypoplastic right heart syndrome
d. ebstein anomaly

Answer 41

C
Hypoplastic right heart is the underdevelopment of the right heart structures, particularly the ventricle and RVOT/PA. The left heart will be enlarged and the fetus will require intervention postnatally to survive. The foramen ovale and ductus arteriosus must remain patent for survival until surgery can be performed on the heart. This allows blood from the RA to cross the PFO into the LA. The LV receives the blood and sends it to the aorta. The blood moves from the aorta into ductus arteriosus and then the pulmonary artery to supply the lungs with blood. This is the opposite flow direction in the ductus than in fetal circulation. HRHS is a ductal dependent heart defect.

Question 42

Most forms of skeletal dysplasia demonstrate a foreshortened femur throughout pregnancy, except ________ that typically has a normal femur length until later in the second trimester.

a. thanatophoric skeletal dysplasia
b. heterozygous achondroplasia
c. osteogenesis imperfecta
d. campomelic dysplasia

Answer 42

B
Most forms of skeletal dysplasia demonstrate a foreshortened femur throughout pregnancy, except heterozygous achondroplasia that typically has a normal femur length until later in the second trimester. Heterozygous achondroplasia may be missed on a routine second trimester scan if it is performed at 20 weeks or earlier. The femur length is typically normal in the early second trimester. Rhizomelia is identified between week 21-27.

Question 43

Malformation of the cloaca:

a. is commonly associated with a cleft lip/palate
b. most commonly occurs as an isolated anomaly
c. is the most common cause of fetal urethral obstruction in females
d. leads to significant polyhydramnios

Answer 43

C
Cloacal Malformation:
The cloaca is a part of the fetal hindgut and divides to form a rectum, a bladder and the genitalia. This single opening in the perineum, which empties both systems, can become obstructed which results in dilation of both the GI & GU tracts. Most common urethral obstruction in females, posterior urethral valves is the most common bladder outlet obstruction in males. Severe obstruction with oligohydramnios can be lethal.

Question 44

If an isolated cystic hygroma is present AFP levels will be _________, but if a cystic hygroma is present in a fetus with Turner syndrome AFP levels will be _________.

a. normal, decreased
b. increased, decreased
c. normal, increased
d. decreased, increased

Answer 44

A
Cystic hygroma formation will most commonly occur in the cervical spine region. If an isolated cystic hygroma is present AFP levels will be normal, but if a cystic hygroma is present in a fetus with Turner syndrome AFP levels will be decreased.

Question 45

A 20 week fetus demonstrates an echogenic mass below the liver and a dilated duodenum. Color Doppler demonstrates the “whirlpool” sign adjacent to the mass. The AFI measures 28cm. These findings are most suggestive of:

a. gastroschisis
b. allantoic cyst
c. midgut volvulus
d. duodenal atresia

Answer 45

C
Midgut volvulus occurs during the normal retraction of the herniated midgut during development. The bowel and vessels are abnormally twisted after entering the abdomen. An echogenic mass is identified below the fetal liver and the duodenum will be dilated. Anytime blood vessels are involved in torsion, the whirlpool sign is identified from the twisted mass of vessels. Polyhydramnios occurs due to the blockage of the digestive system. Gastrochisis is a mass of bowel outside the fetus. Duodenal atresia is not typically associated with mass formation and the whirlpool sign.

Question 46

Which of the following is the most common type of non-lethal fetal skeletal dysplasia?

a. thanatophoric skeletal dysplasia
b. osteogenesis imperfecta type II
c. heterozygous achondroplasia
d. achondrogenesis

Answer 46

C

Heterozygous achondroplasia is an autosomal dominant disorder.

Question 47

Polyhydramnios is diagnosed when the four quadrant fluid level is greater than _______.

a. 12cm
b. 15cm
c. 28cm
d. 25cm

Answer 47

D

Polyhydramnios is diagnosed when the AFI is greater than 25cm of greater than 8cm using the single pocket method.

Question 48

Which placental grade demonstrates the cotyledons of the placenta on ultrasound examination?

a. 0
b. I
c. II
d. III

Answer 48

D
There are 15-30 cotyledons of the placenta which form septations in the placental tissue. These septations are not normally visualized until later in the pregnancy. As the placenta ages the cotyledons become more defined and look like comma shaped indentations along the basal layer.

Question 49

In the 2nd trimester, documenting a normal lens in each eye on the fetal ultrasound can rule out which of the following abnormalities?

a. arhinia
b. stigmatism
c. cataracts
d. holoprosencephaly

Answer 49

C
Cataracts can be identified in a fetus as early as 15 weeks. The lens with a cataract will demonstrate a non-round shape with increased opacity. The normal lens should be a round mildly echogenic ring that is anechoic in the center. Fetal cataracts are associated with maternal rubella infection, Pierre Robin syndrome, Trisomy 13 and 21.

Question 50

Tetralogy of Fallot consists of a group of 4 primary cardiac defects that include right ventricular hypertrophy, VSD, pulmonary stenosis and:

a. small left ventricle
b. overriding aorta
c. aortic coarctation
d. interrupted IVC

Answer 50

B
Tetralogy of Fallot consists of a group of 4 primary cardiac defects that include right ventricular hypertrophy, VSD, pulmonary stenosis and an overriding aorta.