Annually, intrauterine infection with cytomegalovirus (CMV) causes between 1,000 and 3,000 infants to be mentally retarded and/or deaf. These effects occur following primary maternal CMV infection during the first half of pregnancy. Seronegative mothers with children under age two years attending daycare and the seronegative women caring for these children have significantly increased risk of acquiring CMV from their children or children in their care. The rate of infection in these women is between 10 percent and 30 percent per year compared to a rate of
