This article presents an overview of foreign and domestic data (Web of Science, e-LIBRARY, Scopus, PubMed) for the period 19982021, devoted to the system of immune protection of the mother and fetus during normal and pathologically occurring pregnancy. According to the results of the analysis of the literature data, changes occurring at the level of cellular and humoral immunity were revealed, and the mechanisms of innate and adaptive immunity, complement systems in such pathologies of pregnancy as miscarriage, threat of termination, preeclampsia, infectious complications were described. A complex system of protection against fetal rejection is a certain regulatory factor in maintaining the immunological balance during the entire gestation period, and a violation in its work underlies the formation of complications of the early and late postpartum period, as well as neonatal pathologies.