Fetal treatment and long-term neonatal outcomes in severe maternal red cell alloimmunization - a single-centre experience.

Objectives: Haemolytic disease of the fetus and newborn (HDFN) occurs due to maternal IgG alloantibodies that actively cross the placenta and bind to paternally derived fetal antigens on the erythrocytes. The aims of this study were to describe the Slovenian cohort of patients with severe HDFN, who required fetal treatment, to review the fetal treatment strategies, and to describe pregnancy and neurodevelopmental outcomes. Case series presentation: Data on patients who developed severe HDFN between 2006 and 2021 and were treated at our institution were collected retrospectively. Primary care pediatricians were contacted regarding neurodevelopmental outcomes of surviving infants. There were 19 pregnancies affected with severe HDFN. The most commonly implicated antigen was RhD. Seventeen children were liveborn. Sixteen fetuses were treated with intrauterine transfusion (IUT). Two children had developmental delay at the corrected age of 2 years. Conclusions: In this study, the Slovenian national cohort of severe cases of HDFN is described for the first time. Prevalence of RhD alloimmunization was higher in comparison to the literature. A combined treatment with therapeutic plasmapheresis, immunoglobulins and IUT was successful. Three quarters of newborns were born in the late preterm period. Overall survival rate and long-term neonatal adverse outcomes in our cohort were in line with the literature.