Doppler ultrasound has many types and many applications in obstetrics. Normally, the uteroplacental arteries are invaded by endovascular trophoblast. Malinvasion is associated with maintenance of high uteroplacental vascular resistance and intrauterine growth restriction (IUGR) and pre-eclampsia. Several Doppler screening studies have demonstrated an association between increterine arteries and subsequent development of pre-eclampsiaased impedance to flow in the u, IUGR.