Human parvovirus B19 infection during pregnancy.

Human parvovirus B19 (B19) has been implicated as the cause of fifth disease and has been associated with fetal death. We identified pregnant women who were at risk of contracting B19 infection during an outbreak of fifth disease. The sera of 12 women classified at high risk of exposure and 19 classified at low risk were tested during prenatal care, at delivery, or at both times for IgG and IgM antibodies to B19. Four women at high risk but none at low risk were considered infected because they were IgM positive. One IgM-positive woman gave birth to a stillborn hydropic fetus whose tissues were positive for B19 DNA by a nucleic acid hybridization assay. The other three IgM-positive women gave birth to normal offspring, of whom one had IgM-positive cord serum. We conclude that B19 infection during pregnancy can lead to fetal infection with at least two associated outcomes--no adverse effect on the fetus or fetal death.