Is organized screening for cytomegalovirus (CMV) infection necessary during pregnancy? While the question is debated, theAcademy of Medicine comes out again in favor of such a device [1]unlike the High Council of Public Health (HCSP)who ruled out in a recent opinion[2] any systematic early screening for CMV infection at the start of pregnancy. There High Authority of Health has, for its part, been seized of the question and should issue an opinion at the end of 2024 [3].
500 newborns per year develop medium and long-term after-effects
Cytomegalovirus infection can cause serious consequences in the newborn when it occurs during pregnancy (deafness, psychomotor delay). This type of consequence would be of the order of 1 to 6 per 100,000 births. In France, currently, systematic screening for CMV infection during pregnancy is not recommended. In a recent HCSP report [3]the reasons given for this position are on the one hand the absence of marketing authorization (AMM) in this indication for existing antivirals, the lack of consensus in the screening strategy and the non-demonstration of a favorable benefit-risk ratio of CMV screening in pregnant women compared to current care.
However, there is a legal provision [4] by which “the State can set up, after advice from the High Authority of Health (HAS), a systematic CMV screening program in pregnant women”, which is expected by the end of 2024, indicates the Academy of Medicine. In this context, she speaks out, again, in a press release [1]in favor of such screening, supporting arguments. The first is that around four out of 1,000 newborns in France (i.e. around 2,900 per year) are therefore infected with CMV during their intrauterine life and, among them, around 18% (around 500 per year) will develop medium and long-term after-effects: hearing loss, balance disorders, motor deficit, mental retardation, constituting the leading cause of congenital neurosensory disabilities in our country, apart from genetic anomalies.
Second argument: early maternal serological screening makes it possible to diagnose primary peri-conception CMV infection in previously seronegative mothers – knowing that there is no vaccine to prevent vertical transmission of CMV or congenital infection by the CMV.
“In case of positivity, the search for CMV in the amniotic fluid can make it possible to make the diagnosis of fetal infection and to quickly initiate antiviral treatment of the mother to reduce the fetal viral load and avoid damage to fetal tissues by the CMV,” explains the Academy of Medicine.
A systematic screening recommendation only in Italy
It is true that no antiviral molecule has a Marketing Authorization (AMM) in the indication of primary maternal infections (PIM) [3]. Nevertheless, academicians highlight the fact that the antiviral valaciclovir could be used in the treatment of PIM. At this stage of the analysis, the use of this drug in the treatment of PIM has been the subject of 3 clinical trials (NCT02351102, NCT01651585, NCT05446571).
Among them, the randomized trial of Shahar-Nissan published in 2020 (NCT02351102) concludes that valaciclovir at a dose of 8 g/day is effective in reducing the rate of fetal cytomegalovirus infection after a primary maternal infection acquired at the beginning of pregnancy [5].
“This is the only randomized trial identified to date and published regarding the use of valaciclovir in the prevention of vertical transmission. No clinically significant adverse events were reported in this trial,” specifies the HAS. [3].
Since December 2023, routine screening for CMV infection in pregnant women is recommended in Italy [6] but it appears to be the only country to have adopted such a recommendation. “Australia and Canada offer targeted screening while the United Kingdom and Germany do not recommend screening for cytomegalovirus infection during pregnancy,” specifies the HAS.
Thirdly, the Academy of Medicine in France considers that the feasibility of such screening is entirely realistic and that it “could be organized, since the commercial serological techniques, available and used routinely, are standardized, automated and accessible throughout the country.
“The networks of biologists and gyneco-obstetricians, and the CMV reference centers are able to organize themselves to expand and support the implementation of CMV screening, already partly in place in certain regions, notably the Island from France,” she insists.
A public health problem to be taken into account in all its dimensions
In summary, “faced with the observation of serious congenital CMV infections, easily preventable using effective antiviral treatment well tolerated by the mother and the fetus, the National Academy of Medicine renews the recommendation” that it had moreover already expressed previously [6]namely that:
– “this public health problem is taken into account in all its dimensions, including ethical ones and that, in particular, all the costs induced by lifelong disabilities, borne by families and by society, are included in the analysis of the benefit/risk ratio of screening. (The academicians point out, in fact, that in its latest opinion, the HCSP failed to include, in the analysis of the costs incurred for society, the lifelong care of disabled children).
– the means of CMV screening are put in place, including anti-CMV IgG and IgM screening in the first trimester and monitoring of seronegative women, on the basis of a decision-making algorithm, as recommended by the National College of French Gynecologists and Obstetricians ;
– cohort studies and monitoring of the impact of the measure be developed, particularly based on the national health data system.”
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