DOPPLER STUDIES OF FETAL CEREBRAL BLOOD-FLOW

Doppler flow velocity waveforms from fetal cerebral vessels can be rel iably obtained by a transabdominal or transvaginal scanning route. Cha nges in pulsatility imply alterations in cerebral impedance and reflec t the physiological regulatory mechanisms underlying pathological proc esses during pregnancy. In fetuses severely distressed due to failure of placental function, the ratios reflecting the redistribution of fet al circulation (e.g. the 'brain-sparing effect') help to identify fetu ses at risk for fetal hypoxia. Apart from providing an increase in med ical knowledge, this non-invasive technique is proving to be clinicall y useful.