There exists a hypothesis that at the beginning placenta is infected which, however, continues to function as a barrier in transmission of cytomegalovirus to fetus. When occurs deterioration of body barrier properties, the virus may enter blood of fetus.
90% of infected fetuses have no signs of infection. 5 – 15% of infected newborns will have cytomegalovirus after birth. Infection of child may occur during birth when child passes through birth canal. Also this virus may be found in breast milk, therefore more than half children that are fed with breast milk may get cytomegalovirus in first year of their life.
Manifestation of congenital cytomegalovirus is caracterized with retardation in growth and development, increase of spleen and liver, haematological defections, dermatic eruptions, yellow disease and other signs of infection.
However, damage of central nervous system is most dangerous disease manifestation characterized with microcephalism, cerebral atrophy and hearing loss. In brain tissue are found calcifications that are a sign of future development of mental retardation and other neurologic disorders in infected children.
Mortality in very high (10 - 15%) in newborns who developed signs of disease. In rest of 85 – 90% of survived children may be observed neurologic deviations and mental retardation.