Prenatal diagnosis of fetal cytomegalovirus infection after primary or recurrent maternal infection

Objective: To determine the reliability of prenatal diagnosis of cytomegalovirus infection in women with primary or recurrent infection. Methods: Amniotic fluid (AF) samples from 117 pregnant women were evaluated for cytomegalovirus culture and cytomegalovirus-DNA detection. Neonatal and postnatal samples also were examined to confirm or exclude transmission of maternal-fetal cytomegalovirus infection. Results: Of 25 women with primary cytomegalovirus infection, 13 (52%) had cytomegalovirus-positive AF samples by polymerase chain reaction (PCR), nine of which also were diagnosed by culture. All eight neonates born to mothers whose AF was cytomegalovirus-positive by PCR and culture were cytomegalovirus-infected, and three were symptomatic. One aborted fetus had cytomegalovirus-DNAemia. Of four women with cytomegalovirus-positive AF samples by PCR only two delivered asymptomatic cytomegalovirus-infected neonates and two aborted (one fetus had cytomegalovirus encephalopathy). Of 45 mothers with recurrent infection, two with AF cytomegalovirus-positive by PCR and culture, and another with cytomegalovirus-positive AF samples by PCR only, aborted cytomegalovirus-DNA-positive fetuses. Of the other seven women with cytomegalovirus-positive AF samples by PCR only, two delivered asymptomatic cytomegalovirus-infected neonates, two delivered neonates cytomegalovirus-positive by PCR only (one was symptomatic), and three delivered infants cytomegalovirus-negative by PCR and culture. All 47 mothers with nonactive cytomegalovirus infection and cytomegalovirus-negative AF samples had uninfected neonates. Polymerase chain reaction was superior to viral culture in sensitivity and negative predictive value (100% compared with 57% and 94%, respectively) but was lower in specificity and positive predictive value (97% and 83%, respectively, compared with 100%). Conclusion: Prenatal diagnosis of fetal cytomegalovirus infection should include PCR in addition to viral culture, particularly for congenital cytomegalovirus infections following maternal recurrence.