Parvovirus B19 in pregnancy: a sensitive diagnostic molecular assay

Parvovirus B19 (B19V) is a common childhood infection. It causes particular concern where a pregnant woman has had contact with a B19V-infected individual, or where maternal B19V infection is suspected. During pregnancy, from as early as six weeks’ gestation, B19V can transfer from mother to fetus across the placenta. Such infection may cause hydrops fetalis, miscarriage or poor outcomes (including severe neurological disease) in surviving babies.1

Molecular assay
Diagnosis of maternal infection relies on the detection of IgM and IgG antibodies. The presence of IgG antibodies to B19V indicates a previous infection, but it is estimated that approximately 25–45% of women of childbearing age do not possess these antibodies and are therefore susceptible to infection.2

First-line serology testing will indicate current active B19V infection; however, when serological test results are negative but infection is still suspected,3 clinicians can rapidly confirm diagnosis using the new, highly sensitive Iam Parvo molecular assay. This confirmation is particularly important in the eight- to 12- week period after maternal infection, when the sensitivity of IgM antibody detection varies (63–70%) and serological testing alone may not give the full picture.4 Rapid diagnosis of infection allows the fetus to be monitored and appropriate care referrals to be made.