Detection of active Epstein-Barr infection in pregnant women.

Sera taken from pregnant patients and their newborns at delivery were examined for evidence of primary or reactivated Epstein-Barr virus infection. Of 102 women, 37 showed serological signs of reactivated and two signs of primary infection. A mild congenital defect was observed in association with one of the two cases of maternal primary infection. Infants of mothers with reactivated infections remained healthy during the one year follow-up after birth.