Primary cytomegalovirus infection in adolescent pregnancy.

In a prospective study of 3,253 pregnant adolescents, 1,404 were seronegative for cytomegalovirus (CMV). Specimen collection at each antenatal visit, including urine for viral culture and serum for complement-fixing antibody, allowed definition of primary CMV infection in 14 subjects (1%). Seven of 14 subjects delivered congenitally infected infants, including 5/7 subjects with third trimester infections, and 2/5 subjects with second trimester infections. The single mother with a first trimester infection delivered an uninfected infant, despite recurrent maternal viremia. The mean birth weight of congenitally infected infants did not differ significantly from the mean birth weight of uninfected infants. None of the infants had stigmata of cytomegalic inclusion disease. One infected infant died suddenly at 6 weeks of age from pneumonia. Follow-up examinations of the six living children failed to detect cognitive, behavioral, or audiologic sequelae. These data demonstrate that primary maternal CMV infection occurs in 1% of susceptible women and is associated with a 50% risk of intrauterine infection. Fetal infection, particularly if it occurs late in pregnancy, is not invariably accompanied by fetal damage.