Early prenatal diagnosis of hydrocephalus.

The aim of the present study was to assess the accuracy of various measurements of the lateral ventricles (LVs) for the early prenatal diagnosis of evolving congenital hydrocephalus. A prospective study was conducted among 61 normal pregnancies, and 20 pregnancies complicated by neural axis malformations, between 19 and 24 weeks' gestation. The following ultrasound measurements were obtained: atrial width (AW); atrial-width/cerebro-atrial distance (CAD); left ventricular width/hemispheric distance, and cerebro-frontal horn/hemispheric width (HW) distance. Atrial width or AW/CAD had the highest diagnostic accuracy of 97.1% between 19-21 weeks; and 100% between 22-24 weeks. The other two parameters had improved accuracy as gestational age increased. However, between 19-21 weeks the other parameters were below 90% in their diagnostic accuracy. These data demonstrate that the simple measurement of the AW, used either singly or as a ratio with the CAD is effective for the early prenatal diagnosis of evolving hydrocephalus.