Antenatal CMV screening, testing, and treatment strategies in Europe: a 2024 survey

Congenital cytomegalovirus (cCMV) is the most common congenital infection globally, affecting approximately 0.5% of all live births in high income settings, with long-term sequelae affecting around a fifth of infected infants. Recently, interest in antenatal CMV screening has increased but current practices and impact are unclear. Our objective was to describe policy and practice around antenatal CMV screening, testing, and treatment in Europe, including the use of universal antenatal screening, in the context of the emerging evidence base for use of valaciclovir to reduce CMV vertical transmission (VT).

A web-based survey was distributed to healthcare professionals within antenatal services with knowledge of CMV testing/treatment practices, from 29 April 2024 to 24 July 2024. Responses from Europe were analyzed. Where multiple responses were submitted from the same healthcare service, the most complete response was kept for the analysis.

We received responses from 73 centers in 21 countries in Europe, mostly 76% (55/72) from tertiary centers. Overall, 52% (38/73) had a CMV testing policy and 61% (23/38) reported that this had been introduced or significantly updated in the last 2 years. Half of respondents (53%, 39/73, from 11/21 countries) reported routine offer of CMV testing to pregnant woman at their center (universal antenatal screening), sometimes with gestational age limits, and mostly (67%, 26/39) on an "opt-out" basis. Universal antenatal CMV screening was more common among centers with formalized testing policies than those without (84% (32/38) vs. 20% (7/35) respectively, χ² = 30.19, p < .01). For all sites, screening tests included CMV IgM and IgG, with 36% (14/39) offering IgG avidity, and 8% (3/39) using PCR. Of the 39 centers offering universal screening, the coverage was estimated to be >95% of pregnant women at half (18/39) of centers. Fifty-nine percent (23/39) of centers reported routinely offering repeat testing. Of 39 centers routinely offering testing, only 69% (27/39) gave advice on reducing CMV acquisition risk routinely to pregnant women. Medication was offered for prevention of CMV VT or tertiary prevention of cCMV disease at 82% (60/73) and 78% (56/72) of centers, respectively. Of 59 sites offering treatment for secondary and/or tertiary prevention and responding to a question on frequency of treatment monitoring, 93% (55/59) reported monitoring blood tests at least monthly. Forty-three percent of centers offering treatment lacked a formal procedure for reporting adverse drug reactions. Overall, 83% (58/70) respondents supported CMV testing (49 strongly, nine moderately), but 59% (41/70) identified at least one concern/risk.

This survey of antenatal CMV policies and practice at 73 centers in Europe highlights substantial variation in policies and practice, reflecting variation in national screening guidelines and the evolving evidence base around valaciclovir to reduce CMV VT risk. A recent opinion paper and statement have called for consideration of universal screening but also highlighted important evidence gaps around its implementation, risks, benefits, and cost-effectiveness. Responses to this survey suggested that valaciclovir is already quite widely used for prophylaxis of CMV VT in the context of maternal primary infection in early pregnancy, at participating sites. Our findings suggest that research to inform safe and equitable decisions around implementation of CMV testing and universal screening is urgently needed, in addition to epidemiological research to underpin screening decisions tailored to specific settings. Shared research priorities are needed to ensure testing and treatment are carried out in an evidence-based and equitable way.