Report of fourteen cases of nonimmune hydrops fetalis in association with hemorrhagic endovasculitis of the placenta.

Hemorrhagic endovasculitis of the placenta is a distinct vasodestructive process of unknown cause that has been associated with perinatal morbidity and mortality. A relationship between nonimmune hydrops fetalis and hemorrhagic endovasculitis has not been previously described. At a large teaching hospital, six cases of nonimmune hydrops fetalis were identified out of 72 cases of hemorrhagic endovasculitis over 6 years, for an incidence of 8%. Conversely, these same six cases represented 24% of the 25 cases of nonimmune hydrops fetalis from this time period. Eight additional cases of nonimmune hydrops fetalis were found among 2064 cases of hemorrhagic endovasculitis at the Michigan Placental Tissue Registry. In eight of the total 14 cases, after congenital malformations and cytomegalovirus infections were excluded, hemorrhagic endovasculitis was the only significant associated pathologic finding evident. The significance of the relationship between nonimmune hydrops fetalis and the vascular abnormalities of hemorrhagic endovasculitis remains to be determined.