Holoprosencephaly: prenatal sonographic diagnosis

Area of Science:

• Medical Imaging
• Prenatal Diagnosis
• Developmental Biology

Background:

• Holoprosencephaly (HP) is a severe congenital brain malformation.
• Accurate prenatal diagnosis is crucial for management and counseling.
• Distinguishing HP from other conditions like fetal hydrocephalus is essential.

Purpose of the Study:

• To evaluate the accuracy and spectrum of sonographic findings in holoprosencephaly.
• To determine if alobar and semilobar HP can be differentiated from other fetal hydrocephalus cases using ultrasound.
• To document associated intracranial and extracranial abnormalities in HP.

Main Methods:

• Retrospective review of 14 prenatal sonography cases diagnosed with holoprosencephaly (HP).
• Comparison with 58 cases of fetal hydrocephalus diagnosed during the same period.
• Analysis of intracranial features (midline echo, thalami, ventricles) and extracranial anomalies.

Main Results:

• Holoprosencephaly (HP) was accurately distinguished from fetal hydrocephalus by absent midline echo, fused thalami, and abnormal ventricles.
• Alobar HP showed complete thalamic fusion, while semilobar HP exhibited partial fusion and ventricular separation.
• Associated findings included dorsal cysts, facial anomalies (proboscis, midline cleft, hypotelorism), and extracranial abnormalities (polydactyly, renal dysplasia).

Conclusions:

• Prenatal sonography offers a reliable method for diagnosing holoprosencephaly (HP).
• Distinctive intracranial sonographic features allow differentiation between alobar and semilobar HP, and from other causes of fetal hydrocephalus.
• A spectrum of intracranial and extracranial findings can be observed in fetuses with HP.