Objective — to reveal pathomorphological placental characteristics in women with threatened premature birth. Subject and methods. Social and clinicoanamnestic data were analyzed in 117 pregnant women with threatened premature delivery at 22—36 weeks’ gestation. The course and outcomes of pregnancies were traced in all the pregnant women; placentas from 60 puerperas were studied pathomorphologically. Results. In spontaneous premature birth at 24—36 weeks’ gestation, the main pathomorphological placental changes include grades I—II placental hypoplasia caused by impairments in vascular cytotrophoblast invasion and gestational spiral artery remodeling with the development of placental hypoperfusion, large focal, centrally located chronic hemorrhagic infarcts, a total intervillous space thrombosis area of more than 35%, as well as postinflammatory hypovascularization and impaired differentiation of a vasculostromal component of the terminal portions of the villous tree in the presence of inadequate development of compensatory processes. Grade I placental hypoplasia, the total area for chronic uterine and fetal circulatory impairments being not more than 23% of the area of the maternal surface of the placenta, as well as basal, parietal deciduitis and compensatory hyperplasia of the vascular component in the intermediate and terminal villi are main signs of placental structural rearrangement in women with threatened premature delivery who have given birth to a full-term baby. Conclusion. Analysis of poor sociomedical factors and pathomorphological placental changes will be able to elaborate a personified approach to prevention of premature birth and to pregravid preparation for subsequent pregnancy. The authors declare no conflicts of interest.