Accuracy of prenatal diagnosis of isolated aqueductal stenosis.

Objective: The objective of this article is to determine the success rate of prenatally diagnosed isolated aqueductal stenosis (AS) as a first step in an evidence-based reassessment of ventriculoamniotic shunting for isolated AS.

Methods: Cases of ventriculomegaly at Magee-Womens Hospital between 2006 and 2013 were ascertained. AS was suspected when prenatal ultrasound and magnetic resonance imaging (MRI) demonstrated signs of pressure hydrocephalus. The prenatal diagnosis generated by ultrasound and MRI was compared with the postnatal diagnosis based upon neonatal neuroimaging.

Results: The initial query of the Magee-Womens Hospital database resulted in 370 cases of ventriculomegaly. After exclusion for associated central nervous system malformations, 110 cases of severe ventriculomegaly remained. The imaging studies on each fetus were reviewed, and cases of prenatally diagnosed AS were identified. The median gestational age of the ultrasound diagnosis and prenatal MRI was 23 weeks 3 days and 33 weeks 3 days, respectively. All cases of prenatally suspected isolated AS (six of six) and cases of AS with other associated central nervous system anomalies (six of six) were correctly identified.

Conclusion: An accurate prenatal diagnosis of isolated fetal AS is possible. This is an important first step in an evidence-based reassessment of ventriculoamniotic shunting for isolated AS. © 2014 John Wiley & Sons, Ltd.