In Utero Treatment of Severe Fetal Anaemia due to Parvovirus B19 in One Fetus in a Twin Pregnancy – A Case Report and Literature Review

BACKGROUND: Parvovirus B19 (PVB19) is a well-established cause of nonimmune hydrops fetalis and fetal anaemia in pregnancy. However, discordant viral infection of only 1 fetus in a twin pregnancy is a rare occurrence. CASE REPORT: A 40-year-old female with dichorionic, diamniotic twin pregnancy presented at 22 weeks with fetal hydrops and severe anaemia in 1 twin. Maternal PVB19 infection was confirmed, and the affected fetus was treated with a single intrauterine transfusion. The only subsequent complication developed was that the affected fetus was growing on the 5th centile. The affected twin continued to grow, and 2 live twins were delivered by caesarean section at 36 weeks. By 18 months of age, the affected twin had normal development. CONCLUSION: PVB19 may selectively affect 1 fetus in a dichorionic, diamniotic twin pregnancy and may be treated efficiently with intrauterine transfusion. Discordant viral infection in this case suggests that the viral load may be limited to 1 placenta and/or that different individual immunological fetal response starts very early in utero.