Since the tragedy of rubella epidemic in Australia in 1940 and the resulting fetal malformations from maternal infection , more interest and research were directed toward the teratogenic effect of viral diseases during pregnancy and many viruses were implicated as a causation of abortion , congenital malformation and disease of the newborn . And so, the objective of this work is to study the etiology, epidemiology, clinical course of viral infections during pregnancy and to study the relative risk of the vertical transmission of the disease to the neonates, and the preventive measures to minimize or prevent hazardous fetal outcome.