In the UK, 50% women in antenatal clinics are seropositive for CMV. Incidence of congenital CMV infection is ~3 in 1,000 live births. Placental transmission rates are ~40% during primary infection and 1% for reactivated infection. The earlier the gestation at transmission, the worse the prognosis.
>90% infants are asymptomatic but can still develop sensorineural hearing loss.
Other symptoms/signs are: IUGR, microcephaly, thrombocytopenia, jaundice, hepatitis, pneumonitis, periventricular calcification, chorioretinitis and cataracts.
Reference: Rennie & Roberton’s Textbook of Neonatology, 5th Ed, 2005. London: Churchill.