The authors examined in a prospective study in 25 pregnant women blood flow in the uterine artery during haemorrhage in early pregnancy with the diagnosis of imminent abortion. The control group was formed by a group of 25 women with intact pregnancy, in the first trimester. For examinations an ultrasound apparatus ATL MK 600 was used, the authors evaluated the S/D ratio and RI from five consecutive cycles. The mean values of the S/D ratio in the investigated group were 4.85 +/- 0.22, in the control group 4.41 +/- 0.24 which is a statistically significant difference. Similarly the mean RI values in the investigated group were 0.79 +/- 0.01, in the control group 0.77 +/- 0.02--the difference is statistically significant. The results confirmed the assumption that by monitoring of the blood flow in the uterine artery in women with bleeding during the first trimester of pregnancy it is possible to detect relatively early risk patients.