On average, about 40% of babies born to those who had a primary CMV infection during pregnancy will become infected themselves. Of the 40% who become infected, 20% will develop medical complications over the first few years of life. Symptoms can include low birth weight, deafness, blindness, mental disability, small head, seizures, jaundice, brittle teeth, and damage to the liver and spleen.
While a child may develop some of the above symptoms, no baby develops all of them and some infants have no symptoms at all. Each year in the United States, about 1 in 750 children are born with or develop disabilities as a result of CMV infection. For women who have been infected at least six months prior to conception, the rate of newborn CMV infection is about 1%, and these infants appear to have no significant illnesses or abnormalities.