ABSTRACT

Objective: To analyse 3 cases of parvovirus B19 infection in a pregnant woman followed by transplacental transmission to the fetus.

Design: A retrospective study.

Setting: Department of Obstetrics and Gynecology, University Hospital, Olomouc.

Methods: Parvovirus B19 vertical transmission from a pregnant woman to the fetus was diagnosed in 3 cases. Serologic testing of IgG and IgM antibodies against parvovirus B19, cytological bone marrow examination and parvovirus B19 DNA analysis by PCR methods were performed. The fetal anemia was predicted by measurements of peak systolic velocities in the middle cerebral artery (MCA-PSV).

Results: There were three pregnancies in all (1st - single, 2nd and 3rd - dizygotic twins). In the 1st and 2nd pregnancy the diagnosis of parvovirus B19 infection was set on the basis of erythroblastopenia diagnosed in the neonatal period or early infancy. In the 2nd pregnancy (dizygotic twins) intrauterine death of one twin occured. In the 3rd case (dizygotic twins) the diagnosis was already set in the 20th week of pregnancy. Subsequently the fetal anemia was predicted by doppler examination. The fetuses did not require invasive intrauterine intervention and mild anemia was diagnosed after delivery. Progressive intrauterine growth retardation of one twin was observed. Neither cardiomegaly nor fetal hydrops did not occur. All mothers were asymptomatic during the whole pregnancy.

Conclusion: Parvovirus B19 infection should be excluded in all cases of nonimummune fetal hydrops, severe fetal anemia, cardiomegaly, intrauterine grow retardation (IUGR) and chronic erythroblastopenia diagnosed in the neonatal period or early infancy. The presence of IgM and IgG antibodies against parvovirus B19 is highly specific but their negativity is insufficient for the exclusion of a parvovirus B19 infection. Viral DNA testing by PCR method is the only reliable method avalilable.

Key words: parvovirus B19, fetal anemia, middle cerebral artery peak systolic velocity, Doppler, cardiomegaly, myocarditis, hydrops, intrauterine growth retardation