“…Maternal infections may harm the foetus either directly by infection of the embryo, as in the case of rubella, or by a toxic effect. The role of viruses in the aetiology of congenital malformations has been fully reviewed by Blattner and Heys (1961), and the problem of rubella has recently received detailed consideration by Lundstrdm (1962). Since maternal viraemia may persist for several weeks after clinical evidence of the disease has disappeared (Fish, 1965), conception should be avoided and contraception practised for one or two months after rubella or contact with it.…”