At the center of fetal cerebral circulation examinations is the vessel called "media cerebri (MCA)", which has a prominent role in feeding the cerebral cortex. In the case of a lack of oxygen in utero, the first step of defense is the dilation of this cerebral vessel. In the case of incipient splenic insufficiency, the abnormal value of the cerebral flow ultrasound can in some cases precede the abnormal NST by a week, thus it plays a primary role in the diagnosis of the fetal condition.

THE by examining fetal umbilical cords and veins we can also infer the existence of placental insufficiency. Reduced placental circulation most often causes fetal retardation (thinness), which can be accompanied by fetal hypoxia (oxygen deficiency) in severe cases.