Aim. To evaluate the mechanisms of regulation of blood flow in the uterine arteries during the formation of chronic placental insufficiency caused by an exacerbation of cytomegalovirus infection (CMVI) in the second trimester of pregnancy.Materials and methods. The concentration of IL-1β, IFN-γ, IL-4, IL-2 and the systolic-diastolic ratio (SDR) in the right (RUA) and left uterine arteries (LUA) were determined in 90 women in the second trimester of pregnancy, uncomplicated and complicated by exacerbation of CMVI. Retrospectively, 2 groups were distinguished. Group 1 (control) was represented by 30 women with CMV-seronegative physiological pregnancy, group 2 (main) included 60 patients with acute phase of chronic CMVI and consisted of subgroups 1 and 2. Subgroup 1 included 30 women with exacerbation of CMVI, initiating the development of chronic compensated placental insufficiency (CCPI), subgroup 2 − 30 patients with acute phase of chronic CMVI, leading to the formation of chronic subcompensated placental insufficiency (CSPI) in the third trimester of gestation.Results. In women of the 1st group in the blood serum, the concentration of IL-1β (Me [Q1- Q3]) was 18.0 [13.4-36.3] pg/mL, IFN-γ − 134.4 [114.2-151.3] pg/mL, IL-4 − 26.2 [20.3-51.3] pg/mL and IL-2 − 27.9 [18.2-38.0] pg/mL; SDR in RUA – 1.95 [1.87-2.30] relative units and SDR in LUA – 1.84 [1.73-2.25] relative units. In patients of subgroup 1, in comparison with the control one, the concentration of IL-1β increased to 87.3 [55.6-98.2] pg/mL (p=0.000001), IFN-γ − up to 237.3 [191.4-318.6] pg/mL (p=0.000001) and IL-2 − up to 77.1 [58.6-92.3] pg/mL (p=0.000001) in the absence of statistically significant changes IL-4 level. There was an increase in SDR in RUA up to 2.45 [2.35-3.46] relative units (p=0.000001) and SDR in LUA up to 2.80 [2.31-3.05] relative units (p=0.000001). In subgroup 2, in comparison with subgroup 1, higher values of IL-1β were recorded (1.67 times, p=0.000001), IFN-γ (1.38 times, p=0.000015), IL-2 (1.36 times, p=0.00808), SDR in RUA (by 1.35 times, p=0.0105) and SDR in the LUA (by 1.08 times, p=0.0307), as well as a decrease in the level of IL-4 (by 1.84 times, p=0.000002). In women of subgroup 1, there was a direct relationship between the level of IL-1β, IFN-γ, IL-2 and SDR in the RUA (r=0.54, p<0.01; r=0.74, p<0.001 and r=0.58, p<0.001, respectively). The correlation between IFN-γ and SDR in the LUA was determined (r=0.40; p<0.05). In subgroup 2, there was a relationship between IL-4 and SDR in RUA (r=-0.59; p<0.001), as well as IL-2 and SDR in RUA (r=0.39; p<0.05). A correlation was recorded between the concentration of IL-1β, IFN-γ, IL-2 and the SDR value in the LUA (r=0.39, p<0.05; r=0.58, p<0.001 and r=0.57, p<0.001, respectively).Conclusion. Exacerbation of CMVI in women in the second trimester of gestation, leading to the formation of CSPI, in contrast to a similar viral infection that initiates the development of CCPI in the third trimester of pregnancy, is characterized by a more pronounced activation of the systemic inflammatory response, an increase in resistance to blood flow, as well as differences in immuno-hemodynamic relationships that determine the maintenance of vascular tone in the basin of the right and left uterine arteries.