It is known that the pathological course of pregnancy is associated with a disturbance in the «mother-fetus» complex and leads to specific clinical consequences at the molecular-cellular, tissue, organ, organismic and population levels of organization. The mechanism of the pathogenic action of the isoimmunization effect is very complex and still remains insuficiently deciphered. However, the pathogenesis of morphofunctional disorders associated with isoimmunization, an important role is played by changes in the system of organs responsible for adaptation and survival. Therefore, in farms where the fact of the isoimmunization in animals has been established, it is necessary to pay special attention to the creation of conditions conducive to the normalization of the functional systems of adaptation of newborn animals. The material for the research was the lungs, intestines, kidneys, and thymus. Only fresh material was investigated. Sampling up to 0.5 cm thick for histological examination was carried out after forced slaughter. Fixation was carried out with a neutral aqueous 10 % formalin solution. From the obtained parafin blocks, histological sections with a thickness of 4-6 µm were made, which were stained with hematoxylin and eosin. When describing the morphofunctional state of organs, the structure, cellular composition, and the state of blood vessels were described. Isoimmunization of sows during pregnancy is manifested by a characteristic clinical and morphological complex that differs from other infectious and non-infectious diseases. The most characteristic pathomorphological signs are: hypoplasia, delay in differentiation, degenerative changes in the respiratory, digestive, urinary systems and organs of immunogenesis.