Fetal Ventriculomegaly

The atrium of the lateral ventricle (measured at the level of the glomus of the choroid plexus, across the atria) is normally <10 mm. Ventriculomegaly is diagnosed when the atrial diameter is ≥10 mm.

Classification (based on atrial width)

• Mild (borderline): 10–12 mm
• Moderate: 13–15 mm
• Severe: >15 mm (sometimes called hydrocephalus when progressive and associated with increased head size/intracranial pressure)

Severe Ventriculomegaly

Figer

Ultrasound report line (Findings):Each Lateral ventricles are markedly dilated measuring >15 mm at the atrial level, with ballooning of the ventricular atria, consistent with severe ventriculomegaly.
Right atria:15.0 mm
Left atria:17.5 mm
Conclusion: Severe Ventriculomegaly
Recommendation: Detailed fetal neurosonography and anomaly scan to assess associated CNS and extra-CNS anomalies.
Consider fetal MRI for further evaluation of brain parenchyma and associated anomalies.
Recommend counseling and evaluation for possible chromosomal, genetic, or TORCH infectious etiologies.

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Etiology / Causes
Ventriculomegaly can be isolated or associated with other abnormalities:

1. Obstructive causes
   • Aqueductal stenosis
   • Neural tube defects (spina bifida, encephalocele)
   • Masses (tumors, hemorrhage, arachnoid cyst)
2. Non-obstructive causes
   • Chromosomal abnormalities (e.g., Trisomy 21, 18, 13)
   • Congenital infections (CMV, toxoplasmosis, Zika virus)
   • Cortical malformations (agenesis of corpus callosum, holoprosencephaly, lissencephaly)
   • Brain atrophy from ischemic/hemorrhagic injury

Sonographic Features

• Lateral ventricle atrium >10 mm, measured in axial plane at level of thalami and cavum septi pellucidi.
• Dangling choroid plexus sign (choroid plexus appears to “hang” within enlarged ventricle).
• Assess for associated findings:
  • Intracranial anomalies (corpus callosum agenesis, Dandy–Walker malformation)
  • Extracranial anomalies
  • Fetal growth restriction
  • Signs of infection (calcifications, microcephaly)

Prognosis

• Isolated mild ventriculomegaly (10–12 mm): ~80–90% have normal neurodevelopmental outcome.
• Moderate (13–15 mm): Outcome depends on progression and associated anomalies; ~60–70% normal if isolated.
• Severe (>15 mm): High risk of neurodevelopmental impairment, motor/cognitive deficits, or death.

Evaluation / Work-up

• Detailed fetal neurosonography (evaluate for structural CNS malformations).
• Fetal MRI (to assess cortical and midline structures).
• Genetic testing (amniocentesis with karyotype and microarray).
• TORCH screening for intrauterine infections.
• Serial ultrasounds to monitor progression.

Evaluation / Work-up

• Detailed fetal neurosonography (evaluate for structural CNS malformations).
• Fetal MRI (to assess cortical and midline structures).
• Genetic testing (amniocentesis with karyotype and microarray).
• TORCH screening for intrauterine infections.
• Serial ultrasounds to monitor progression.

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Note: If you select English, answer all questions in English.
यदि आप हिंदी चुनते हैं, तो सभी प्रश्न हिंदी में हल करें।

1. Ventriculomegaly in the fetus is defined when the atrial width of the lateral ventricle is: 1. भ्रूण में वेंट्रिकुलोमेगाली को तब परिभाषित किया जाता है जब लोइर वेंट्रिकल के एट्रियल चौड़ाई कितनी होती है?
A. < 5 mm
B. 5–9 mm
C. ≥ 10 mm
D. ≥ 20 mm

2. Which measurement plane is recommended for atrial width? 2. एट्रियल चौड़ाई मापने के लिए किस विमान की सिफारिश की जाती है?
A. Transventricular plane at the level of the atria (thalamic plane)
B. Coronal plane through the cerebellum
C. Sagittal midline
D. Any axial plane is fine

3. Mild ventriculomegaly is commonly defined as: 3. हल्की वेंट्रिकुलोमेगाली को सामान्यतः किस रूप में परिभाषित किया जाता है?
A. 10–12 mm
B. 13–15 mm
C. 16–19 mm
D. ≥ 20 mm

4. Which of the following is a commonly recommended next step when isolated mild ventriculomegaly (10–12 mm) is detected? 4. जब अलग-थलग हल्की वेंट्रिकुलोमेगाली (10–12 मिमी) पाई जाती है तो आमतौर पर अगला कदम क्या सुझाया जाता है?
A. Immediate fetal surgery
B. Offer detailed anatomic scan + fetal MRI + maternal TORCH/infection testing and targeted genetic testing
C. No follow-up required
D. Terminate pregnancy immediately

5. Bilateral ventriculomegaly is considered more concerning than unilateral because: 5. द्विपक्षीय वेंट्रिकुलोमेगाली एकतरफा की तुलना में अधिक चिंताजनक मानी जाती है क्योंकि:
A. It is more likely associated with chromosomal or structural anomalies
B. Unilateral always means benign
C. Bilateral ventricles are easier to measure
D. It rules out infection

6. Severe ventriculomegaly is commonly defined as an atrial width of: 6. गंभीर वेंट्रिकुलोमेगाली को सामान्यतः किस एट्रियल चौड़ाई के रूप में परिभाषित किया जाता है?
A. 10–12 mm
B. 13–15 mm
C. >= 15 mm
D. < 10 mm

7. Which associated finding increases the risk of an adverse neurodevelopmental outcome? 7. कौन सी सह-संबंधित खोज प्रतिकूल नयूरोविकासात्मक परिणाम के जोखिम को बढ़ाती है?
A. Isolated mild ventriculomegaly with normal other anatomy
B. Ventriculomegaly with additional CNS anomalies or chromosomal abnormality
C. Stable ventricular size on follow-up
D. Normal fetal MRI

8. Best caliper placement for atrial measurement is: 8. एट्रियल माप के लिए सर्वश्रेष्ठ कैलीपर प्लेसमेंट क्या है?
A. Inner-to-inner wall of atrium at level of the glomus of choroid plexus
B. Outer-to-outer wall through frontal horn
C. Diagonal across the third ventricle
D. From skull to skull (biparietal)

9. Fetal MRI is particularly useful because it: 9. भ्रूण MRI विशेष रूप से उपयोगी है क्योंकि यह:
A. Replaces ultrasound for routine screening
B. Better evaluates associated cortical, posterior fossa or migrational abnormalities
C. Measures ventricular width more accurately than ultrasound in all cases
D. Is not recommended in ventriculomegaly evaluation

10. The most important parental counseling point when isolated mild ventriculomegaly is confirmed and detailed workup is normal is: 10. जब अलग-थलग हल्की वेंट्रिकुलोमेगाली की पुष्टि हो जाए और विस्तृत परीक्षण सामान्य हों तो माता-पिता को सबसे महत्वपूर्ण परामर्श क्या है?
A. Guarantee of normal neurodevelopment
B. Explain generally favorable prognosis but discuss residual risk and offer follow-up and postnatal assessment
C. Immediate referral for termination
D. No follow-up needed ever