CONGENITAL AND MATERNAL CYTOMEGALOVIRUS INFECTIONS IN A LONDON POPULATION

Objective-To determine if women at risk of having babies infected with cytomegalovirus (CMV) can be identified antenatally. Design-Prospective serological and demographic study of pregnant women and virological study of their newborn infants. Setting-Teaching hospital in London. Subjects-3315 pregnant women and 2737 of their babies. Main outcome measures-Quantitative detection of CMV IgG antibodies; qualitative detection of CMV IgM antibodies; demographic characteristics of mothers; qualitative and quantitative titration of CMV viruria in newborn. Results-Congenital CMV infection was found in nine newborn babies (0.33%) two of whom had symptoms. Serological testing of the nine mothers showed four primary and five recurrent infections; both of the symptomatic children were born in the latter group. Testing for CMV specific IgM antibodies or quantitation of IgG antibodies in early pregnancy sera could not differentiate those women at risk of giving birth to babies infected or damaged by CMV from the rest of the population. Quantitation of viruria confirmed that those babies most at risk of CMV disease have the highest titres of CMV. Conclusions-(i) Since laboratory tests in pregnant women cannot reliably identify fetuses at risk of disease, screening for asymptomatic maternal infection coupled with termination of pregnancy cannot be recommended. (ii) Since 'immune' women can still give birth to babies affected by CMV, we propose that future CMV vaccines should be used to immunize children with the aim of eradicating CMV infection in preference to selective immunization of sero-susceptible females.