Routine cytomegalovirus screening is not necessary

Cytomegalovirus (CMV) is the most common cause of congenital infection. It affects between 0.3 and 0.5 births in Western Europe. About 5-10% of infants infected in utero are born with abnormalities. Yet in France, the importance of maternal and congenital CMV infections is poorly documented. This is why the National Institute for Public Health Surveillance (InVS) launched a national epidemiological survey in 2004. It aims not only to estimate the number and characteristics of congenital infections, but also to describe the practices of biologists and clinicians for maternal, fetal and neonatal diagnosis.

A question is asked regularly. Should we systematically screen during pregnancy? In 2004, the National Agency for Accreditation and Health Assessment (Anaes, now part of the High Authority for Health), had not recommended it.

The authors of the InVS survey confirm this position. “Our results published this week allow us to estimate that most symptomatic congenital infections are detected in France during pregnancy or at birth”. According to their analyzes, nearly 300 congenital infections due to cytomegalovirus (CMV) are diagnosed in France. The multidisciplinary team of the InVS notes that around sixty infections lead to termination of pregnancy. And among the newborns, about fifty present at birth with abnormalities: psychomotor retardation, single or bilateral deafness.

These results consolidate the position of the National College of French Gynecologists and Obstetricians (CNGOF). In the current state of knowledge, a systematic screening policy for CMV during pregnancy is not justified.

“In 2002, a group of CMV experts launched an information campaign suggesting the need to systematically perform CMV serology in all pregnant women. The rationale for this screening was that a positive serology would reassure nearly half of them, recalls a representative of the CNGOF. Such systematic screening has no demonstrated benefit. On the other hand, it would have many perverse effects, such as the anxiety of many pregnant women in whom the serology is negative (about 50% of women), not to mention that of women whose IgM antibodies are positive. By promoting this anxiety, we are increasing the number of requests for additional examinations: repetition of biological tests, multiplication of antenatal ultrasounds, carrying out amniocentesis involving a risk of miscarriages … We can fear that systematic screening will inevitably lead to requests for terminations of pregnancy in situations of simple doubt ”.
However, if the results of the InVS study do not validate the idea of ​​systematic screening, they show that the reasons and medical practices for detecting cytomegalovirus infection vary depending on the services. For example, when infection is confirmed in pregnant women, testing for transmission to the fetus is not systematic. The research is carried out in 48% of the cases. It is mainly performed in case of screening for ultrasound abnormalities (67%).

Questions to Isabelle Parent du Châtelet, epidemiologist, co-author of the InVS study

“There is no treatment to offer”

Are these figures different from previous studies?

Isabelle Parent du Châtelet. There are few studies in France which estimate the number of these congenital infections. An evaluation was carried out in 2004 by Anaes to assess the value of screening for cytomegalovirus infection in pregnant women. It had not led the experts to recommend systematic screening. Their results are no different from what we find in this study today.

The question of screening is therefore not raised again?
CPI This question is not raised again because it is not only the figures that are taken into account, but it is also the absence of treatment to offer, and in particular of antenatal treatment if one were to detect a maternal CMV infection. . In addition, transmission of the virus is not systematic in the event of infection.

What are the findings in terms of detection practice?
CPI The study showed that there was a certain heterogeneity of current practices with regard to the detection of a maternal infection. This infection is sought most of the time when there is screening for ultrasound abnormalities or when it is known that the maternal infection took place at the very beginning of pregnancy and therefore with greater risk of fetopathies. However, if there are no screening recommendations, you should know that this screening is sometimes performed without a sign of primary infection.
Interview with MG