Placental and fetal pathology in infectious mononucleosis. A possible indicator for Epstein-Barr virus teratogenicity.

Placentae and membranes were studied microscopically in five cases of pregnancy interruption due to maternal infectious mononucleosis in the first 2 months of pregnancy. This viral disease, caused by Epstein-Barr virus and apparently rare in pregnancy, induced specific placental lesions. In the decidua, these lesions were manifested by perivasculitis and necrotizing deciduitis. The membranes exhibited slight to moderate chorionitis. In the villi, endovasculitis, perivasculitis, and occasional vascular obliteration were found, as well as mononuclear and plasma cell villitis, with many large atypical vacuolated cells resembling plasma cells. Three fetuses were studied, two of which exhibited myocarditis. The fact that there were placental lesions in all cases studied, and that two of the fetuses exhibited myocarditis, must stimulate further research concerning the possible teratogenicity of this virus in man.