Prediction of fetal anemia dynamics and justification of intervals between intrauterine transfusions in Rh­alloimmunized pregnancies

Abstract

DOI: 10.52705/2788-6190-2026-03-3

The objective: to identify prognostic factors influencing the dynamics of fetal anemia and to substantiate the intervals between intrauterine transfusions (IUTs) in Rh-alloimmunized pregnancies based on a comprehensive clinical and instrumental analysis.
Materials and methods. A retrospective descriptive and analytical study was conducted in 27 pregnancies complicated by Rh alloimmunization, in which 63 cordocenteses with IUTs were performed during 2024–2026. The following parameters were analyzed: gestational age at each intervention, dynamics of maternal anti-Rh antibody titers, middle cerebral artery peak systolic velocity (MCA-PSV), invasively determined fetal hemoglobin and hematocrit levels, transfusion volume, intervals between procedures, placental location, and technical aspects of the interventions.
Results. The intervals between IUTs were determined by a combination of gestational age, invasively measured fetal hemoglobin level, MCA-PSV values, and the presence of structural ultrasound markers of fetal anemia. Placental location influenced the technical performance of the procedure and the profile of postprocedural risks. Following repeated IUTs, some fetuses demonstrated discordance between MCA-PSV values and fetal hemoglobin levels, which likely reflects specific features of cerebral hemodynamic adaptation after repeated transfusions. Comprehensive assessment of ultrasound and laboratory parameters allowed individualized determination of the timing between repeated IUTs.
Conclusions. Determination of intervals between IUTs in Rh alloimmunization should be based on an integrated assessment of gestational age, invasively measured fetal hemoglobin level, hemodynamic and structural ultrasound markers of anemia, as well as technical procedural factors. Isolated use of individual parameters is insufficient for optimizing fetal therapy strategy and predicting the dynamics of fetal anemia.