Fetal anemias (FA) are rare diseases in pregnancy and are divided into two major categories: immune and non-immune. Non-immune fetal anemias (NFA) are a extremely heterogeneous group of FAs with different etiopathogenesis. Due to the introduced Rh-prophylaxis, they are becoming important in clinical practice, although their frequency has remained unchanged. A common feature of all NFAs is the absence of specific maternal antibodies to fetal erythrocyte antigens. NFAs can occur gradually as a consequence of chronic diseases or acutely, due to bleeding in the fetoplacental circulation. The most common causes of chronic NFA include infections, anemia in twin pregnancies, placental or fetal tumors, and inherited diseases, such as hereditary anemias and congenital metabolic errors. Fetomaternal hemorrhage (FMH) and rupture of the previa fetal blood vessels, the so-called vasa previa, cause acute FA and decompensation of the cardiovascular system. In some cases, the etiology of NFA remains unknown despite detailed diagnostics. Fetal hydrops is the final stage of FA and most commonly indicates delayed diagnosis and worse prognosis. Diagnostic procedures in NFA are numerous and are determined by the causative agent. The "gold standard" in NFA diagnostic processing is the measurement of peak systolic velocities in the middle cerebral artery (MCA-PSV) by color Doppler, thus reducing the need for invasive procedures by 70%. Cordocentesis today is exclusively related to the intrauterine transfusion (IUT) procedure. Due to different etiopathogenesis, different methods of NFA treatment are also available. Acute anemias are treated surgically or by emergency cesarean section, and IUTs are most often used in the treatment of chronic NFA. They are a demanding but effective and safe method of treating most NFA with which fetal mortality due to FA has fallen below 10%. Laser ablation of vascular anastomoses is the method of choice in the treatment of NFA arising as a complication of monochorionic (MC) twin pregnancies, e.g., twin-to-twin transfusion syndrome (TTTS) or twin anemia and polycythemia (TAPS). In addition to IUT, laser ablation of vascular anastomoses is also used to treat the twin anemia polycythemia sequence (TAPS) (TAPS). Nevertheless, it is the treatment of twin-to-twin transfusion syndrome. There are insufficient studies that have long-term followed the neurological development of children after NFA, however according to most studies conducted, only a small percentage of children treated with IUT due to fetal anemia have some degree of neuromotor deficit.