Reproductive: Congenital Fetal

Question 1

What are the most common congenital heart diseases associated with Down syndrome?

Answer 1

• AV canal defect
• Ventricular septal defect

Question 2

What is the most common intraabdominal pathology associated with Down syndrome?

Answer 2

Duodenal atresia

Question 3

Fetal ultrasound findings suspicious for Down syndrome

Answer 3

• Congenital heart disease
• Duodenal atresia
• Short femur length
• Echogenic bowel
• Choroid plexus cyst
• Nuchal translucency
• Nuchal fold thickening
• Echogenic focus in cardiac ventricle

Question 4

What percentage of fetuses with Down syndrome will have congenital heart issues?

Answer 4

More than half

Question 5

Which trisomy is most often associated with a choroid plexus cyst?

Answer 5

Trisomy 18

Note: Also seen in trisomy 21 (Down syndrome).

Question 6

When is nuchal translucency measures?

Answer 6

First trimester (between weeks 9 and 12)

Question 7

What is a normal nuchal translucency thickness?

Answer 7

3 mm or less (in the first trimester)

Note: If > 3 mm, think Downs syndrome.

Question 8

What is being measured (**)?

Answer 8

Nuchal fold thickness

Question 9

What is being measured?

Answer 9

Nuchal translucency (the anechoic area between the neck/occiput and the skin)

Question 10

What is a normal nuchal fold thickness?

Answer 10

6 mm or less

Note: If > 6 mm, think Down syndrome or Turners.

Question 11

How should the fetal head be positioned while measuring nuchal translucency?

Answer 11

In neutral position (nasal bone should be visualized with the head in the mid-sagittal position)

Question 12

What maternal blood tests are run to screen for Down syndrome?

Answer 12

• Free beta-hCG
• PAPP-A (pregnancy associated plasma protein-A)

Question 13

No other anatomic abnormalities

Answer 13

Think amniotic band syndrome (limb/finger amputation due to constriction from amniotic bands)

Question 14

Answer 14

Think amniotic band syndrome

Note: Linear echogenicities entangling the fetus.

Question 15

Missing fingers in an otherwise normal neonate…

Answer 15

Think amniotic band syndrome

Question 16

Hydrops fetalis

Answer 16

A bad condition where there is fetal edema due to accumulation of fluid in the fetal tissues/organs

Question 17

Common causes of hydros fetalis

Answer 17

• Rh sensitization from a prior pregnancy
• TORCH infections
• Turners
• Twin gestation
• Alpha thalassemia

Question 18

Ultrasound diagnosis of hydrops fetalis

Answer 18

Two of the following:

• Pleural effusion
• Ascites
• Pericardial effusion
• Subcutaneous edema

Question 19

Answer 19

Hydrops fetalis

Note: Pleural effusions and ascites.

Question 20

Fetal ultrasound

Answer 20

Hydrops fetalis

Note: Pericardial (A) and pleural (B) effusions.

Question 21

Answer 21

Hydrops fetalis

Note: Thickened placenta (C) and scalp edema (D).

Question 22

Chiari II malformation

Answer 22

Caudal herniation of the cerebellar vermis, brainstem, and 4th ventricle due to low CSF pressure (CSF leaking out an open neural tube defect)

Question 23

Answer 23

Think Chiari II malformation

Note: This is the “lemon head” appearance due to flattening of the bilateral frontal bones in the setting of insufficient CSF pressure to create the normal curvature. Once the brain grows large enough to push the frontal bones out during the third trimester, this appearance goes away and the skull appears normal.

Question 24

Answer 24

Banana-shaped cerebellum, suggestive of a Chiari II malformation

Note: Left image shows banana cerebellum and right image shows normal bilobed cerebellum.

Question 25

When are the banana and lemon signs visible on fetal ultrasound?

Answer 25

Lemon sign is only present during the second trimester (in the third trimester the brain grows large enough to push out the frontal bones and restore normal skull curvature) The banana sign is present during the second and third trimesters

Question 26

Which sign is more sensitive and specific for Chiari II malformations: lemon or banana?

Answer 26

Banana sign (appearance of cerebellar fusion) is more sensitive and specific Note: On the test, the lemon sign will almost always indicate Chiari II, but in real like it can also be seen with Dandy-Walker, Absent corpus callous, ecephaloceles, etc.

Question 27

What is the most common cause of non-communicating hydrocephalus in a neonate?

Answer 27

Aqueductal stenosis

Question 28

Common causes of ventriculomegaly in a fetus/neonate

Answer 28

- Hydrocephalus (communicating and non-communicating) - Cerebral atrophy

Question 29

What is being measured by the double headed arrow?

Answer 29

Ventricular atrium diameter

Question 30

What is a normal ventricular atrium diameter in a fetus?

Answer 30

10 mm or less Note: Greater than 10 mm indicated ventriculomegaly.

Question 31

Answer 31

"Dangling choroid plexus" which suggests ventriculomegaly if greater than 3 mm

Question 32

Answer 32

Choroid plexus cyst

Question 33

Choroid plexus cysts are associated with...

Answer 33

- Trisomy 18 - Trisomy 21 - Turner's syndrome - Klinefelter syndrome Note: If isolated, this usually doesn't mean anything, but you should look hard for other defects.

Question 34

What is the most common fetal facial anomaly?

Answer 34

Facial clefts (e.g. cleft lip/palate)

Question 35

Around 80% of pts with cleft lips have ______

Answer 35

Cerebral palsy

Question 36

Facial clefts are associated with ______ approximately 30% of the time

Answer 36

Chromosomal anomalies

Question 37

Answer 37

Cleft lip

Question 38

Fetal ultrasound

Answer 38

Cleft palate

Question 39

Answer 39

Cystic hygroma Note: Complex cystic mass in the posterior neck.

Question 40

Cystic hygromas are associated with...

Answer 40

- Turner's syndrome - Down syndrome

Question 41

Answer 41

Cystic hygroma Note: Complex cystic mass in the posterior neck.

Question 42

What is the most common neural tube defect?

Answer 42

Anencephaly (total absence of the cranial vault and brain above the level of the orbits)

Question 43

Answer 43

Anencephaly

Question 44

Answer 44

Anencephaly Note: Absence of cranium (arrow).

Question 45

Congenital diaphragmatic hernias almost always occur on the...

Answer 45

Left (85%) Note: The liver is protective on the right.

Question 46

Answer 46

Congenital diaphragmatic hernia on the left

Question 47

Answer 47

Congenital diaphragmatic hernia on the left

Question 48

Answer 48

Congenital diaphragmatic hernia on the left

Question 49

Why is congenital diaphragmatic hernia associated with a high mortality?

Answer 49

Pulmonary hypoplasia (due to compression of the lungs by the hernia)

Question 50

Congenital diaphragmatic hernias are always associated with...

Answer 50

Intestinal malrotation

Question 51

Fetal ultrasound

Answer 51

Echogenic intracaardiac focus (usually a calcified papillary muscle) Note: This occurs in the normal general population (5%), but occurs more commonly in Down syndrome (12%) and trisomy 13 (so you should look closely for other abnormalities).

Question 52

Fetal tachycardia

Answer 52

Heart rate > 180 bpm

Question 53

Fetal bradycardia

Answer 53

Heart rate < 100 bpm

Question 54

Answer 54

Think duodenal atresia Note: This is the "double bubble sign" where the stomach and duodenum are distended.

Question 55

How can you tell whether bowel is echogenic on fetal ultrasound?

Answer 55

Normal bowel should be isoechoic to liver, but echogenic bowel will be isoechoic to the iliac crest bone

Question 56

Echogenic bowel is associated with...

Answer 56

- Cystic fibrosis - Down syndrome (and other trisomies) - Viral infections - Bowel atresia

Question 57

What is the most common tumor of the fetus/infant?

Answer 57

Sacrococcygeal teratoma

Question 58

Answer 58

Think sacrococcygeal teratoma (most common tumor in the fetus)

Question 59

What are the most common locations for a sacrococcygeal teratoma?

Answer 59

- External to pelvis (47%) - Dumbell shaped with components both internal and external to pelvis (34%) - Internal to pelvis (9%)

Question 60

Are sacrococcygeal teratomas usually benign or malignant?

Answer 60

Benign (80%) Note: Those presenting in older infants tend to have a higher malignant potential.

Question 61

Complications of a sacrococcygeal teratoma

Answer 61

- Mass effect (GI issues, hip dislocation, incontinence due to nerve compression) - High output cardiac failure - Premature delivery - Shoulder dystocia - Tumor hemorrhage

Question 62

Answer 62

Think autosomal recessive polycystic kidney disease Note: Massively enlarged bilateral kidneys with oligohydramnios.

Question 63

Fetal ultrasound

Answer 63

Think posterior urethral valve Note: Distended bladder with appearance of diverticulum (distended proximal urethra). Look for bilateral hydronephrosis.

Question 64

Measurement is below the 5th percentile

Answer 64

Short femur, suggestive of skeletal dysplasia (also seen in Down syndrome)