The atria of the fetal lateral ventricles: a sonographic study of normal atrial size and choroid plexus volume.

Abstract

This large prospective study confirms previous observations of mean atrial size. However, four standard deviations above the mean is 12 mm, suggesting currently used cutoffs for normal atrial size are too low. Other parameters, such as choroid plexus filling, may be helpful markers of normalcy in fetuses with atrial measurements between 8 and 12 mm.