Background: Doppler velocimetry studies have been widely used in antenatal fetal surveillance to predict adverse pregnancy outcomes especially in high risk pregnancies. This is mainly due to the ability of Doppler velocimetry study to define abnormal utero placental circulation. Objective : To identify high risk pregnancies among antenatal clients using Doppler velocimetry of the umbilical artery for prediction of adverse pregnancy outcomes. Methods: This was a prospective study at Aminu Kano Teaching Hospital among 415 high risk pregnant women. Socio-demographic factors of the clients, past obstetric history, medical and surgical history and the history of the current pregnancy were recorded on a questionnaire. At the radiology unit, in the Department of Radiology, Doppler velocimetry of the umbilical artery was conducted using 3.5 m Hz convex of the Mindry Digital Ultrasound Imaging System (Model DP-8800Plus; Shenzen Mindray Biomed electronics, China), following application of water soluble coupling gel over the lower abdomen. The umbilical artery of each patient was identified by placing the transducer over the lower abdomen and by randomly directing it towards the uterine cavity to identify the umbilical cord using amniotic fluid acoustic window. The angle between the ultrasound beam and the direction of the blood flow was adjusted to less than 350 . The resistive indices ± diastolic notch and systolic diastolic ratio (S/D) were recorded.