The incidence of human parvovirus B19 infection during pregnancy and its impact on perinatal outcome.

A prospective study of parvovirus B19 infection during pregnancy was conducted at a large teaching hospital in Barcelona, Spain. Women (1610) who were < 28 weeks pregnant at enrollment were screened for parvovirus infection. The prevalence of IgG positivity was 35.03% (564/1610). The incidence of acute infection during pregnancy was 3.7% (60/1610). There were five abortions among the B19-infected women but only one was caused by parvovirus, as assessed by histologic examination and polymerase chain reaction assay. The incidence of fetal loss caused by parvovirus was, therefore, 1.66% (1/60). The remaining 55 pregnancies were uneventful, and at 1 year of age, none of the infants had serious abnormalities. The incidence of vertical transmission of infection was estimated at 25%. This study provides evidence that although acute parvovirus infection may occur relatively commonly during pregnancy, an adverse fetal outcome is a rare complication.