You are an expert in maternal infections and fetal infections. Cytomegalovirus infection in pregnant women is one of the leading causes of congenital neurological problems in an unborn child. What is the best way to screen for cytomegalovirus infection in pregnant women? How to go about if the positive result in serology is known? So cytomegalovirus for sure is new rubella. Rubella is gone from most countries. Unfortunately, not all countries. But rubella is gone in most countries because of vaccination. There is no yet a vaccine for CMV. There are many hopes in the RNA vaccine now to develop vaccines for all kinds of infection, especially CMV. At the moment, that does not exist. So it's either primary prevention, not exposing the woman to the CMV infection, young children, or secondary prevention after screening in the first trimester for serology IgM and IgG. If the presence of both IgG and IgM testify for early infection in pregnancy, there is secondary prevention that is efficient with valacyclovir. It prevents the virus from crossing during the first trimester because it is an embryopathy that is a problem like rubella, not anything else. The latest developments have occurred with cytomegalovirus CMV. CMV is worldwide. One of the main difficulties for CMV is that if you are immune, that does not protect you completely from another infection. And this non-primary CMV infection is a black box. Nobody knows how to diagnose that in the mother. In Europe, in the United States, especially the East Coast, these are mainly primary cytomegalovirus infections. So if you screen for cytomegalovirus early in pregnancy, and women do have a primary infection, which you diagnose by asking the serology. If they develop cytomegalovirus IgM and IgG early in pregnancy, these are the most dangerous infections because they are at the beginning of pregnancy or just before, pre-conceptional.
The rate of cytomegalovirus transmission is high. It is about 30%. And the risk of sequelae by damaging the embryo and then the fetus is high, also at 30%. The latest developments have occurred from our group. Both in early cytomegalovirus diagnosis, we can diagnose that with trophoblast biopsy CVS, chorionic villus sampling. It is a very early cytomegalovirus diagnosis. So if a woman, for example, gets a cytomegalovirus infection at seven weeks, you can do CVS at 13 weeks. And the good thing is that if that CVS is normal, negative, there is no cytomegalovirus infection on the placenta. There is no other way for the virus to cross the baby than crossing the placenta. So if the virus is not in the placenta, it means the cytomegalovirus infection has not occurred in the first trimester. And what we've clearly showed here is that if the cytomegalovirus infection occurs after that, there is no risk of abnormal development. That's a major advance because it's very reassuring. So your screen early, you exclude the diagnosis, and then that's fine. There is no target for the virus after the first trimester if the virus can damage the hearing ability and damage the brain. If the cytomegalovirus infection happens after the first trimester, it does not hit the brain or the hearing process. And if cytomegalovirus does happen early, you know it early also with the CVS diagnostic test, and you can treat. You can treat cytomegalovirus with antiviral drugs. One of the oldest, the Acyclovir oo valacyclovir that is being given in, in pregnancy for herpes, for example. You can use that for CMV. And that works well if you treat early. There are new drugs coming up. And we are conducting several clinical trials here to find an antiviral cytomegalovirus drug that is more potent for the severely cytomegalovirus-infected fetuses.