Follow-up study of lympho-histiocytic villitis and incidental retroplacental hematoma.

Placentas are usually submitted for pathologic examination based on obstetrical indications. We hypothesized that the placenta may have diagnostic value to the infant independent of obstetrical events. We specifically tested whether lymphohistiocytic villitis (noninfectious) would predict autoimmune or alloimmune disease based on transfer of activated maternal T-cells to the fetus and whether clinically silent placental separations (retroplacental hematomas, RPH) would predict neurologic injury in the infant.