Congenital Cytomegalovirus Infection.

Cytomegalovirus (CMV) infection is the most common congenital infection worldwide and the leading cause of nonhereditary sensorineural hearing loss in children. Congenital CMV infection (cCMV) is asymptomatic in 85% to 90% of newborns at birth. Symptomatic congenital disease occurs most frequently after primary maternal infection in pregnancy. Although much less common, symptomatic cCMV carries a mortality risk of up to 7% to 12% in the early neonatal period. The risk of severe morbidity is increased due to central nervous system damage, leading to neurodevelopmental delays, hearing loss, and vision impairment. Asymptomatic disease is not entirely benign, as 10% to 15% go on to develop long-term morbidities. Despite these risks, clinician awareness of cCMV among women of reproductive age is much more limited than for congenital toxoplasmosis or Down syndrome, which occur at a lower incidence.