Biological Specificities of Fetal Anemia Induced by Parvovirus B19 Infection.

OBJECTIVE

To describe the biological fetal parameters in cases of severe anemia induced by parvovirus B19 (B19V) infection.

METHOD: A retrospective single center study was conducted including cases of fetal anemia due to B19V receiving in utero transfusion (IUT) from January 2011 to May 2024. Biological data from fetal blood at first IUT were collected.

RESULTS

65 cases were included. Median Hemoglobin was 3 g/dL [IQR 2.1-3.8] and median reticulocyte count was low (39.9 G/L [IQR 17.0-71.1]). Lymphopenia and elevated erythroblasts were noted in 37.5% and 59.1% of cases, respectively. High Aspartate aminotransferase (AST) levels and hypoproteinemia were observed in 97.6% and 71.4% of cases, respectively. The median lactate dehydrogenase (LDH) level was high (1556.0 U/L [IQR 611.0-2405.0]). Hydropic fetuses significantly exhibited lower hemoglobin levels (median 2.5 g/dL vs. 3.8 g/dL; p = 0.0315), lower platelet counts (median 30.5 G/L vs. 71.5 G/L; p = 0.0014), higher AST (median 97.0 vs. 20.0 U/L; p = 0.0002) and LDH levels (median 2068 vs. 329.5 U/L; p = 0.0002) compared to non-hydropic cases.

CONCLUSION

Severe fetal anemia due to B19V infection is associated with specific hematological and biochemical anomalies, some of which are more pronounced in case of hydrops.