Aim. To evaluate changes in immunological parameters and umbilical blood flow in pregnant women with exacerbation of chronic bronchitis associated with cytomegalovirus infection (CMVI).Materials and methods. The concentration of secretory immunoglobulin A (sIgA), immunoglobulin E (IgE), circulating immune complexes (CIC), interleukin- 6 (IL-6), interleukin-4 (IL-4) and systolic-diastolic ratio (SDR) in the umbilical artery was studied in 80 women with exacerbation of chronic bronchitis in the second trimester of pregnancy, uncomplicated and complicated by the acute phase of CMVI. The first group was represented by 30 women with cytomegalovirus seronegative physiological pregnancy; the second – 25 patients with exacerbation of chronic bronchitis caused by reactivation of CMVI, complicated by the development of chronic compensated placental insufficiency (CCPI); the third – 25 women with chronic simple bronchitis in the acute stage in the setting of the acute phase of CMVI, initiating the formation of chronic subcompensated placental insufficiency (CSPI) at 30-34 weeks of gestation.Results. In the first group, the concentration of sIgA in blood serum was 4.3±0.26 mg/L, IgE – 3.64±0.23 IU/mL, CIC – 0.091±0.005 AU, IL-6 – 2.41±0.21 pg/mL, IL-4 – 30.1±2.19 pg/mL, cortisol – 527.2±20.95 nmol/L, and SDR in the artery umbilical cord – 3.41±0.06 relative units. In women of the second group, in comparison with the first one, there was an increase in the concentration of sIgA by 1.40 times (p<0.01), IgE – by 1.95 times (p<0.001), CIC – by 1.83 times (p<0.001) , IL-6 – 2.61 times (p<0.001), IL-4 – 1.29 times (p<0.05), cortisol – 1.35 times (p<0.001) in the absence of statistically significant differences the magnitude of vascular resistance in the umbilical artery. In the third group, in comparison with the first one, there was a decrease in sIgA values by 1.26 times (p<0.05) in the setting of an increase in the concentration of IgE by 2.56 times (p<0.001), CIC – by 2.09 times (p<0.001 ), IL-6 – by 3.65 times (p<0.001), IL-4 – by 1.64 times (p<0.001), cortisol – by 1.52 times (p<0.001) and SDR in the umbilical artery – 1.27 times (p<0.001). In women of the third group, in contrast to the second one, a decrease in the concentration of sIgA by 1.77 times (p<0.001), as well as an increase in IgE by 1.31 times (p<0.01), CIC ‒ by 1.14 times (p<0.001), IL-6 ‒ 1.39 times (p<0.001), IL-4 ‒ 1.27 times (p<0.05), cortisol ‒ 1.13 times (p<0.05) and SDR in the umbilical artery ‒ 1.21 times (p<0.001). A direct correlation was established between IL-6 and cord blood flow (r=0.53; p<0.01), as well as an inverse relationship between sIgA and cortisol (r=-0.44; p<0.05).Conclusion. In the second trimester of gestation, exacerbation of chronic simple bronchitis caused by reactivation of CMVI, which initiates the development of CSPI, in contrast to chronic bronchitis in the acute stage, associated with the acute phase of chronic CMVI, which induces the formation of CCPI, is accompanied by an imbalance of nonspecific local and systemic immune responses, as well as stress-reaction, which leads to the growth of SDR in the umbilical artery.