P06.03: Discordant fetal infection for parvovirus in a dichorionic twin pregnancy

Abstract

There are only a very few reports of fetal parvovirus infection in the circumstance of a twin pregnancy. We report a case of differential fetal infection following maternal parvovirus infection in a dichorionic twin pregnancy. A 32-year-old woman was diagnosed with parvovirus infection following exposure to her infected child at 19 weeks’ gestation in a dichorionic diamniotic twin gestation. Maternal seroconversion was documented and parvovirus B19 DNA was present on PCR testing. Fetal monitoring with serial ultrasound assessment was instituted and at 25 weeks gestation Twin I (male) displayed mild ascites, pericardial effusion, placentomegaly and oligohydramnios. The MCA PSV was elevated. Twin II (female) was sonographically unremarkable and the MCA PSV was not elevated. A single fetal intravascular transfusion for Twin I was performed (pretransfusion Hb 80 g/L). Twin I fetal blood was positive for parvovirus B19 DNA and serum demonstrated both IgG and IgM. Following the fetal transfusion the sonographic hydrops resolved, although the placentomegaly persisted. Delivery at 37 weeks’ gestation resulted in live male and female fetuses. Both were vigorous at delivery. Individual neonatal venepuncture showed B19 DNA on PCR to be present in Twin I but absent in Twin II. IgM was present for B19 in Twin I but not Twin II. Both neonates had B19 IgG antibodies, passively acquired from the mother. Histopathology of the placentae demonstrated mild edema in that of Twin I but no inclusion cells. The placenta of Twin II was unremarkable. In conclusion, we present a case of discordant fetal infection in a dizygotic dichorionic twin pregnancy for parvovirus, with a dual live birth at term and no adverse perinatal sequelae. This case demonstrates the ability for differential transplacental infection of this virus and the assistance of MCA flow studies to guide therapy in a multiple pregnancy at risk of parvovirus infection.