Nonimmunologic hydrops fetalis resulting from intrauterine human parvovirus B-19 infection: report of two cases.

Two cases of nonimmunologic hydrops fetalis associated with intrauterine human parvovirus B-19 infection are reported. In these cases, hydrops fetalis was diagnosed with ultrasound at 21 and 22 weeks' gestation after 10 or more days of maternal flu-like symptoms. The outcome was stillbirth in one case and neonatal death in the other. In both cases, intrauterine infection by human parvovirus B-19 was confirmed based on two findings: maternal serum positive for human parvovirus B-19 immunoglobulin M (IgM) antibody, and human parvovirus B-19 DNA detected in the fetal organs using Southern blotting and hybridization with a 32P-labeled probe. Laboratory tests on cord blood demonstrated a red blood cell count of 163 x 10(4)/microL, and nucleated red cells numbering 1267 per 50 white cells in the live-birth case. Histologic examinations of fetal tissues demonstrated leukoerythroblastic reaction in the liver and spleen, granular hemosiderin deposition in hepatocytes and Kupffer cells, and bilirubin deposition in the intercellular space in the liver. This evidence indicates that, in some fetuses with intrauterine human parvovirus B-19 infection, hydropic changes may be induced by the sudden decrease in oxygen-carrying capacity of the blood due to severe anemia caused by the infection.