Fetal Central Nervous System Examination Clinical Practice Guidelines (WAPM, 2021)

World Association of Perinatal Medicine

These are some of the highlights of the guidelines without analysis or commentary. For more information, go directly to the guidelines by clicking the link in the reference.

December 06, 2021

Guidelines for fetal CNS examination were published in Journal of Perinatal Medicine by the World Association of Perinatal Medicine.[1]

During the anatomy scan, use axial scanning to assess the following:

  • Normal shape of the fetal head/skull and cranial bone ossification (trans-thalamic or trans-ventricular planes). Look for bone ossification in the sagittal plane; examine the frontal area to rule out frontal bossing and the occipital area to identify posterior encephalocele

  • Biparietal diameter and head circumference (trans-thalamic plane)

  • Symmetry of hemispheres (trans-thalamic or trans-ventricular planes)

  • Presence of a central interhemispheric fissure and a falx dividing equally the hemispheres (trans-thalamic or trans-ventricular planes)

  • Occipital horn of the lateral ventricle distal to the transducer (trans-ventricular plane). Evaluate both occipital horns of the lateral ventricles

  • Atrial width of the lateral ventricle distal to the transducer (trans-ventricular plane)

  • Presence and orientation of two frontal horns of the lateral ventricles medially separated by cavum septi pellucidi (CSP; trans-thalamic or trans-ventricular planes)

  • Presence of the CSP (trans-thalamic or trans-ventricular planes). The median/midsagittal view should be performed to directly demonstrate the corpus callosum in terms of presence/absence (complete-partial)

  • Presence of two thalami separated from each other in the midline (trans-thalamic plane)

  • Presence of a normal developed silvian fissure could be assessed for its shape at the mid-trimester anatomy scan (trans-ventricular plane as well as trans-thalamic plane)

  • Presence of normal cerebellar hemispheres joined in the middle by the cerebellar vermis (trans-cerebellar plane)

  • Transverse cerebellar diameter (trans-cerebellar plane)

  • Presence of a normal cisterna magna (trans-cerebellar plane)

  • Measurement of the cisterna magna (trans-cerebellar plane)

Assess the presence and regularity of the entire spine (including the sacrum) and integrity of the skin by a sagittal scan.

For more information, go to Ultrasound Examination of Fetal CNS Clinical Practice Guidelines (ISUOG, 2021).


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