High-risk obstetric conditions, such as, cardiac disease, diabetes & hypertension with pregnancy are associated with increased risk of perinatal morbidity & mortality. The effect of these conditions on adverse perinatal outcomeis likely mediated by uteroplacental insufficiency.Thus, evaluation of fetal circulatory system by means of Doppler has become an indispensable tool in evaluating fetal well-being & detecting early hypoxia in growth-restricted fetuses, to precisely time delivery & improveperinatal outcome.