Оbjective — to assess the central nervous system of fetuses with hemolytic disease complicated by immune dropsy before and after intrauterine intravascular blood transfusions. Evaluation of the presence of clinical and laboratory signs of the mother’s mirror syndrome in the development of immune dropsy in the fetus. Material and methods. Three cases of severe hemolytic disease of the fetus, complicated by immune dropsy in terms of gestation of 25—31 weeks, are analyzed and summarized. Results. When evaluating MRI studies before and after intrauterine intravascular blood transfusions, the fetal brain had a structure corresponding to gestational age. The hypoxic-ischemic CNS lesions detected in the early neonatal period in newborns with hemolytic disease are apparently associated with the immaturity of the brain structures. In all cases, pregnancy was complicated by the development of a maternal mirror syndrome (FHI), like preeclampsia, which appears as a «reflection» of dropsy. We identified one of the causes of FHI — immune fetal hydrops. As a result of treatment of severe hemolytic disease of the fetus complicated by the development of immune drop by the method of intrauterine intravascular blood transfusion it was possible to achieve relief of symptoms of FHI. Conclusions. The characteristics of the central nervous system of fetuses with hemolytic disease of severe degree, complicated by the development of immune dropsy and a mirror syndrome in the mother, as the maximum manifestation of pathology, are analyzed. One of the causes of FHI has been identified — immune fetal hydrops — having the possibility of eliminating the cause through intrauterine intravascular blood transfusion to the fetus — the FHI is reversed. When studying the method of MRI of the CNS in fetuses with severe forms of hemolytic disease, visible focal and diffuse changes are not observed both before and after intrauterine treatment. Cerebral ischemia is formed, as a rule, after birth and is apparently the result of the immaturity of the brain structures of newborns, which on average gave birth in terms of 32—33 weeks of gestation.