[Molecular biological demonstration of parvovirus infection in fetal tissue]

We report on the morphological findings in 16 fetuses with serologically confirmed maternal parvovirus B19 infection. Typical routine morphological findings of the hydropic fetuses were the presence of abnormal erythroblasts with typical nuclear inclusions. These infected cells positively stained immunohistochemically with antibodies against a recombinant virus protein, as well as they ultrastructurally contained virus particles. Using in-situ hybridization techniques, we were able to demonstrate the presence of parvovirus B19 genome in the infected cells, while no other cell type was shown to contain virus genome. According to our results the differential diagnosis of fetal parvovirus B19 infection should be considered in each case with hydrops fetalis of unknown origin. The careful routine microscopic examination of fetal tissue may provide evidence for parvovirus infection which should be confirmed by in-situ hybridization analysis.