[Infection with human parvovirus B19 ('fifth disease') during pregnancy: potential life-threatening implications for the foetus].

Four pregnant women, aged 29, 32, 36 and 36 years, respectively, were diagnosed with Human parvovirus B19 (B19V) infection. Only the first woman had exanthema and fever. In the first three cases, the source of infection appeared to be another child; two of these children were infected during a school outbreak. All four foetuses were infected, but the first foetus was asymptomatic and healthy at birth. The second foetus had anaemia and increased blood flow in the middle cerebral artery; it received an intrauterine transfusion and was healthy at birth. The third foetus was almost immobile and had cardiomegaly and hydrops fetalis; it was dead upon induced birth. In the fourth case, pregnancy was uneventful until two days before parturition, when the mother reported a decrease in foetal movement. The infant was born and developed respiratory insufficiency after 8 hours. Imaging revealed multiple bilateral lesions in frontal, occipital and parietal white matter consistent with infarction. The infant died after 5 days. Infection with B19V is associated with a wide range of clinical presentations and outcomes. Effects may range from an uncomplicated pregnancy to severe hydrops fetalis or intrauterine foetal death. Maternal symptoms may be aspecific, which complicates early diagnosis. When maternal B19V infection is suspected, immediate investigation for recent B19V infection should be performed. Quantitative B19 viral load measurements may provide insight into the stage of infection and may guide foetal monitoring. Referral to a foetal therapy unit is essential for hydrops fetalis or severe foetal anaemia. Intrauterine transfusion with erythrocytes significantly improves foetal outcome. Despite a successful transfusion procedure, long-term neurodevelopment may be affected, and developmental follow up is advised.