Congenital CMV Hearing Loss

Leading non genetic cause of hearing loss at birth

Overview

Cytomegalovirus, a common herpesvirus, can pass from mother to fetus during pregnancy, and congenital CMV is the leading non genetic cause of sensorineural hearing loss in children. Most infected newborns show no signs at birth, but a proportion develop hearing loss that may be present at birth or appear and progress later in childhood, so it can be missed by newborn screening. Other possible effects include microcephaly, developmental delay, and vision problems. Congenital infection can only be confirmed by testing samples such as saliva or urine in the first weeks of life, because later infection acquired after birth is common and does not carry the same risks. Antiviral treatment with valganciclovir is used in some infants with symptomatic disease and may help hearing and developmental outcomes. Several regions have introduced targeted or universal newborn CMV screening. Because young children often shed the virus, hygiene measures around toddler saliva and urine are emphasized in pregnancy, and vaccine research is ongoing.