Fetal brain asymmetry is considered a normal developmental processes. The size and shape of the lateral ventricles are interdependence with the brain parenchyma. Abnormal development of the fetal brain may cause unilateral or bilateral ventriculomegaly. Fetal cerebral ventricle measurement is one of the most frequently used sonographic tool for the evaluation of brain development. It is easier to evaluate and measure the distal cerebral ventricle, and therefore data concerning the normal range of asymmetry and the normal progress of the asymmetry are limited.