Epstein-Barr virus (EBV) is perhaps the most ubiquitous member of the herpesviruses family. Similar to herpes simplex virus, EBV infection can lead to a distinct clinical syndrome as well as to asymptomatic shedding of the virus after primary infection. In many parts of the world, infection is universal by age 3 years. In the United States, infection may be postponed until the second or third decade of life. Large prospective studies in the United States and Europe have shown that fewer than 5% of pregnant women are EBV seronegative and that women rarely seroconvert during pregnancy.

Reactivation of EBV during pregnancy could potentially lead to in utero infection. However, in a group of pregnant women with evidence of reactivation as evidenced by a rise in EBV early antigen titers, no embryopathy was detected. In most women who have documented EBV during pregnancy, no fetal effects have been observed. Reports of symptomatic congenital EBV infection are exceedingly rare. One child with documented in utero EBV infection had micrognathia, cryptorchidism, cataracts, hypotonia, thrombocytopenia, and persistent monocytosis, whereas another had evidence of extrahepatic biliary atresia and onset of jaundice at 5 days of life.