Comparative data on the state of venous and arterial blood flow in the maternal-fetoplacental system are presented based on the examination of 148 pregnant women with chronic venous diseases (CVD) of the lower extremities and small pelvis (group 1) and 30 pregnant women without CVD (group 2). The blood flow was measured at 7 points of the maternal-fetoplacental system, viz. maternal inferior vena cava (A), maternal internal iliac vein (D), uterine vein (C), venous plexus of broad ligaments (D), umbilical vein (E), venous duct (F), and fetal inferior vena cava (G). The study revealed correlation between the severity of pathological changes in the veins of the lower extremities and small pelvis and that of placental insufficiency (PI). These changes manifested themselves as the increased number of complications in both pregnant women and newborn infants due to the overall disturbance of the blood flow in the maternal-fetoplacental system. The conditions of blood circulation in pregnant women presenting with class 3 chronic venous insufficiency (CVI) according to the CEAP classificaction were significantly more impaired than in the patients with less severe forms of CVI when compared with the women of the control group having normally developing fetuses. The maximum blood flow rate in the umbilical vein was 9.6 cm/s, mean blood flow rate in the maternal inferior vena cava 21.3 cm/s, maximum systolic blood flow rate 22.1 mm/s, and maximum diastolic blood flow rate 12.1 cm/s. In the fetuses, the mean blood flow in the venous duct was 22.3 cm/s, maximum systolic blood flow rate 31.2 cm/s, and maximum diastolic blood flow rate 27.4 cm/s. The blood flow rate in the venous duct during atrial contractions was 10.5 cm/s (χ2=16.28; p=0.0002). Circulatory disturbances proportional to the severity of CVD were documented in the venous plexus of broad ligaments and in the uterine vein of the women with decompensated and subcompensated forms of CVD. Decompensated CVD was associated with venous refluxes in the internal iliac vein. Moreover, the maximum venous blood flow during systole was slowed down in proportion to the severity of CVD. In all the cases, the diameter of the aforementioned blood vessels increased which suggested venous congestion in the small pelvis that correlated with the severity of CVD.