First trimester sonographic diagnosis of holoprosencephaly

Objective: To describe our experience with sonographic diagnosis of fetal h oloprosencephaly in first trimester. Subjects: A total of three fetuses wit h early prenatal diagnosis of holoprosencephaly were sonographically evalua ted and followed up. Results: The study revealed that all showed monoventri cular cavity, fused thalami, no fair and cavum septum pellucidum. All of th em were correctly diagnosed sonographically in the first trimester. Extracr anial anomalies had also been identified in all three fetuses and all of th em had facial abnormalities. Cytogenetic studies were successfully carried out in only one case. No polyhydramnios was demonstrated in all cases. Conc lusion: This small series indicates that holoprosencephaly can be diagnosed in the first trimester. The most valuable clue to the diagnosis is the dem onstration of the single ventricle. (C) 1999 International Federation of Gy necology and Obstetrics.