Prenatal ultrasound semiography of anencephaly: sonographic-pathological correlations

A better understanding of the ultrasound findings in each of the different types of fetal anencephaly can help to reduce the number of false-negative diagnoses of this condition during the prenatal period. Errors in the estimation of the remaining cerebral tissue (angiomatous stroma, area cerebrovasculosa) can cause false-negative diagnoses or diagnostic confusion with cases of microcephaly or incomplete ossification of the cranial vault. In a retrospective study, 30 fetuses with anencephaly (diagnosed at 13-38 weeks of gestation) were grouped, in terms of their ultrasound results, according to the Nanagas classification. The ultrasound diagnoses were then correlated with those found through autopsy, to identify any errors in the ultrasound classification.