Cytomegalovirus infection in pregnancy.

Cytomegalovirus (CMV) is the most common agent of prenatal (peri- and early postnatal) infection of the newborn with an incidence of 0.2-2.0% (5-10%) depending on the socio-economic status. Only one out of 20 congenitally CMV-infected newborns shows serious symptoms. Another two may reveal mental retardation and other significant handicaps in later age. Perinatal CMV infection occasionally causes atypical pneumonia, mostly combined with Pneumocystis carinii infections similar to reports of AIDS cases. The risk of vertical infection has been quantified. About 2-4% of pregnant seronegative women (40-60% of all) pass a primary, 10-20% of seropositives a recurrent CMV infection. Every third primary infection may result in vertical CMV transmission with poor prognosis in about 25% (40%) of the offspring infected (in the first half of pregnancy). Sources of vertical infection are semen, maternal cell-associated viraemia, ascending genital virus (prenatally), cervical secretion (perinatally), breast milk and saliva (early postnatally). Laboratory diagnosis of CMV infection is performed by many virological and immunological techniques for detecting viral infectivity, structural components, humoral and cellular immunoresponses. Routine diagnostic service is mainly established by virus cultivation in human fibroblasts and by ELISAs on antibodies and antigens.