Ventriculomegaly

Question 1

Describe the proper technique for measuring the lateral ventricle on a fetal ultrasound.

Answer 1

Axial view of the head at the level of the thalami, measure perpendicular to the atrium at the level of the posterior margin of the choroid plexus

Question 2

How is ventriculomegaly defined for a fetus?

Answer 2

Lateral ventricle > than or equal to 10mm

Question 3

What is mild ventriculomegaly?

Answer 3

10-12mm

3% risk of aneuploidy

Question 4

What is moderate ventriculomegaly?

Answer 4

13-15mm

Question 5

What is severe ventriculomegaly?

Answer 5

> 15mm
11% risk of aneuploidy
DDX: Holoprosencephaly, Dandy walker, encephalocele, porcencephaly

Question 6

When ventriculomegaly is identified, what is your differential diagnosis?

Answer 6

Agenesis of corpus callosum
Spina bifida
Normal variant

Question 7

What percentage of cases of ventriculomegaly are bilateral?

Answer 7

?

Question 8

If ventriculomegaly is identified on prenatal ultrasound what workup do you recommend?

Answer 8

Detailed fetal anatomy 
Fetal echocardiogram 
Amniocentesis 
Neurosonography
MRI

Question 9

What is the likelihood of an underlying genetic or karyotypic abnormality in fetuses with isolated ventriculomegaly?

Answer 9

T13
T18
T21

3% in mild
11% in moderate to severe

Question 10

If an amniocentesis is performed for a fetus with ventriculomegaly, what tests do you perform on the amniotic fluid?

Answer 10

Karyotype, CMA

CMV, Toxoplasmosis PCR

Question 11

What is the role of MRI in the evaluation of fetal ventriculomegaly?

Answer 11

MRI can look for additional brain anomalies which is best seen in the third trimester

Question 12

How do you counsel patients regarding prognosis for fetuses with isolated mild ventriculomegaly?

Answer 12

• Prognosis is influenced by other anomalies
• In utero progression associated with increased neurologic sequelae
• Mild ventriculomegaly with normal karyotype -> 4.9%

Question 13

How do you counsel patients regarding prognosis for fetuses with isolated severe ventriculomegaly?

Answer 13

10.7% of females had neurodevelopment delay

Question 14

What are risk factors for worse neurologic sources with ventriculomegaly?

Answer 14

Asymmetrical and bilateral 
Dilation >12mm
Females> male 
increased progression in utero 
If with other anomalies

Question 15

How do you follow a fetus with ventriculomegaly?

Answer 15

Fetal growth

Pediatric neurology

Question 16

When do you recommend delivery for fetuses with ventriculomegaly?

Answer 16

39 weeks

Question 17

Do you consider ventriculomegaly an indication for cesarean section?

Answer 17

Yes, if macrocephaly (HC >40cm)