Association of prenatal closure of the foramen ovale and fetal parvovirus B19 infection in hydrops fetalis.

Stenosis of the foramen ovale was found at autopsy in a preterm hydropic female who died 3 hours after birth. Subsequently, fetal infection by the human parvovirus B19 was diagnosed by serology collected at autopsy and by identifying the viral genome in both the placenta and autopsy liver by polymerase chain reaction. Morphologic findings at autopsy suggested that the disease was in a recovery phase. Prenatal closure of the foramen ovale, as an isolated lesion, is a recognized association of fetal hydrops because right-to-left cardiac shunting through the foramen is obligatory during fetal life. Parvovirus infection is also associated with fetal hydrops, the mechanism being congestive heart failure secondary to acute anemia. Coincidence in this case of both a cardiac and an infective cause of fetal hydrops suggests that the two putative causes are related. We suggest that an episode of fetal congestive heart failure (triggered in this case by anemia caused by fetal parvovirus infection) may initiate prenatal closure of a normally formed and previously patent foramen ovale. If this is true, the congenital anatomic anomaly would represent a cardiac deformation acquired during fetal life rather than a malformation dating from embryonic life.