Cytomegalovirus in pregnancy: to screen or not to screen

Abstract

BackgroundCytomegalovirus (CMV) infection is now the commonest congenital form of infective neurological handicap, recognized by the Institute of Medicine as the leading priority for the developed world in congenital infection. In the absence of an effective vaccine, universal screening for CMV in pregnancy has been proposed, in order that primary infection could be diagnosed and- potentially- the burden of disability due to congenital CMV prevented.DiscussionUniversal screening for CMV to identify seronegative women at the beginning of pregnancy could potentially reduce the burden of congenital CMV in one of three ways. The risk of acquiring the infection during pregnancy has been shown to be reduced by institution of simple hygiene measures (primary prevention). Among women who seroconvert during pregnancy, CMV hyperimmune globulin (CMV HIG) shows promise in reducing the risk of perinatal transmission (secondary prevention), and CMV HIG and/ or antivirals may be effective in reducing the risk of clinical sequelae among those known to be infected (tertiary prevention). The reports from these studies have re-ignited interest in universal screening for CMV, but against the potential benefit of these exciting therapies needs to be weighed the challenges associated with the implementation of any universal screening in pregnancy. These include; the optimal test, and timing of screening, to maximize detection; an approach to the management of equivocal results, and the cost effectiveness of the proposed screening program. In this article, we provide an overview of current knowledge and ongoing trials in the prevention, diagnosis and management of congenital CMV. Recognising that CMV screening is already being offered to many patients on an ad hoc basis, we also provide a management algorithm to guide clinicians and assist in counseling patients.SummaryWe suggest that- on the basis of current data- the criteria necessary to recommend universal screening for CMV are not yet met, but this position is likely to change if trials currently underway confirm that CMV HIG and/ or antivirals are effective in reducing the burden of congenital CMV disease.

The obstetrician, congenital cytomegalovirus, clinical and diagnostic approaches to the pregnant woman

“…The potential benefits of routine screening are outweighed by the harms 10 . Screening women at high risk of acquiring CMV infection, ideally pre-pregnancy, may be considered 8 7,12 .…”

Screening for Cytomegalovirus Infection During Pregnancy in a Teaching Hospital, Western province, Sri Lanka

“…Primary prevention through advising seronegative mothers regarding precautions of hygienic measures is important in minimizing seroconversion. Among women who seroconverted during pregnancy, CMV HIG show significant reduction of perinatal transmission (secondary prevention), and when given to pregnant mother of already infected fetus also have some effect on reducing the risk of malformations (tertiary prevention) 9,10 . Diagnosis of CMV infection usually relies on serological testing.…”

“…And also there are preventive measures including CMV hyperimmunoglobulin (HIG) and antivirals to reduce congenital malformations which are being evaluating in clinical trials at present. If the mother is found to be seronegative during the screening, mother should be strictly advised regarding hygienic practices like frequent hand washing and avoiding close contact with young children to minimize the acquisition of new infection during pregnancy 9,10 .…”

Screening for Cytomegalovirus: An Analysis of Guidelines

“…Children with congenital CMV infection following first trimester infection are more likely to have central nervous system sequelae, whereas infection acquired in the third trimester has a high rate of intrauterine transmission but a favourable outcome [3]. As discussed by Walker et al [1] "Universal screening for CMV to identify seronegative women at the beginning of pregnancy could potentially reduce the burden of congenital CMV in one of three ways. The risk of acquiring the infection during pregnancy has been shown to be reduced by institution of simple hygiene measures (primary prevention).…”

“…Congenital cytomegalovirus (CMV) is the most prevalent infectionrelated cause of neurological damage (impaired development, mental retardation, and neurosensory hearing deficit) since implementation of universal rubella vaccination [1].…”