Chronic pyelonephritis in the structure of extragenital pathology in pregnant women occupies a leading position due to the high prevalence, complicated course of pregnancy and childbirth. Chronic pyelonephritis (CP) triggers a whole cascade of reactions, primarily immune, at the systemic and local level. In CP of pregnant women, the role of the immune system lies not only in the pathological process occurring in the kidneys, but also takes into account a number of changes in the restructuring of the immune system of the pregnant woman. In connection with the above, the study of the role of the immune system of pregnant women with chronic pyelonephritis is of great interest.