Objective: Our aim was to determine the accuracy of ultrasonography in the prenatal diagnosis of agenesis of the corpus callosum and to establish whether ultrasonography can provide prognostic indicators in cases of agenesis of the corpus callosum.
Study design: Prospective ultrasonographic study of the corpus callosum in all cases during an 8-year period in which fetal cerebral ventriculomegaly was detected.
Results: A total of 14 cases of agenesis of the corpus callosum are reported. In seven cases agencies of the corpus callosum was an isolated finding, and in seven cases it was associated with other abnormalities. Six cases involved mendelian syndromes (3 Lissencephaly syndrome, 2 Aicardi syndrome, and 1 Andermann syndrome), and one case was associated with trisomy 13. In 5 of 14 fetuses, all male, agenesis of the corpus callosum was an isolated benign finding. The corpus callosum could never be visualized before midgestation, but diagnosis of agenesis of the corpus callosum was very accurate after 20 weeks.
Conclusion: Prenatal ultrasonographic findings suggestive of agenesis of the corpus callosum should be followed by a careful search for associated anomalies that may indicate genetic syndromes. Isolated agenesis of the corpus callosum is often an isolated, benign finding, particularly in male fetuses. In families at risk for mendelian syndromes associated with agenesis of the corpus callosum, lack of visualization of this structure is suggestive of the diagnosis.