Sonographic evaluation of the normal developmental anatomy of fetal cerebral ventricles: I. The frontal horn.

A prospective ultrasound study was conducted in 179 normal pregnant women with gestational ages ranging from 15-40 weeks. Several biometric measurements were obtained throughout pregnancy, including the cerebrofrontal horn distance of the lateral ventricle, the frontal hemispheric width, and the calculated ratio of cerebrofrontal horn distance/hemispheric width. Curvilinear relationships were found between cerebrofrontal horn distance and gestational age (R2 = 0.597; P less than .0001) and between cerebrofrontal horn distance and the biparietal diameter (R2 = 0.618; P less than .0001). In addition, a curvilinear relationship existed between cerebrofrontal horn distance/hemispheric width ratio and gestational age (R2 = 0.492; P less than .0001) and biparietal diameter (R2 = 0.930; P less than .0001). These data represent a comprehensive characterization of normal growth of the fetal frontal horns. They provide a method by which variations from the norm can be assessed and early prenatal diagnosis of developmental anomalies of the fetal ventricular system can be made.