First trimester sonographic diagnosis of holoprosencephaly

Objective: To describe our experience with sonographic diagnosis of fetal holoprosencephaly in first trimester. Subjects: A total of three fetuses with early prenatal diagnosis of holoprosencephaly were sonographically evaluated and followed up. Results: The study revealed that all showed monoventricular cavity, fused thalami, no fair and cavum septum pellucidum. All of them were correctly diagnosed sonographically in the first trimester. Extracranial anomalies had also been identified in all three fetuses and all of them had facial abnormalities. Cytogenetic studies were successfully carried out in only one case. No polyhydramnios was demonstrated in all cases. Conclusion: This small series indicates that holoprosencephaly can be diagnosed in the first trimester. The most valuable clue to the diagnosis is the demonstration of the single ventricle. (C) 1999 International Federation of Gynecology and Obstetrics.