Cytomegalovirus in pregnancy. Who is at risk? How to diagnose CMV in baby. 6
How do usually pregnant women get infected with cytomegalovirus? Dr. Anton Titov, MD. How is the first step suspicion of cytomegalovirus virus infection is usually raised? Dr. Anton Titov, MD. Right. So as I mentioned, there are two kinds of cytomegalovirus infection, non-primary, and primary. What we know everything about is the primary cytomegalovirus infection. And this is a typical sketch of the target for the virus. A young woman with, high socio-economical level, their first baby is already two and three years old. And usually, this first baby is left in a daycare center because the mother works during the day. This is the typical sketch; 99% of the cytomegalovirus cases are like this. So this is a very high-risk population because these women with that profile, prospectively, when they enter their second pregnancy, have a 10% risk of catching cytomegalovirus virus 10%. There is no such high risk anywhere else in perinatal medicine. And yet, no country in the world is advocating for screening for cytomegalovirus. Even though this profile of women is known, and the cytomegalovirus virus circulates in the nursery. They get infected by their mothers. The virus is everywhere in the baby, in tears in the saliva, urine, and feces. So it’s very difficult to avoid contact, even if they are careful. And also sometimes, which is a shame, they do know, they are very careful themselves, and they ask the husband to do the job. And then the husband is not immune, gets cytomegalovirus, and then contaminates the mother. So it’s hopeless primary prevention. What has been shown recently is that secondary cytomegalovirus prevention is also efficient. So if you screen early, and you get aware of a recent primary infection, valacyclovir, that I mentioned treating infected fetuses, you give to the mother, and you decrease the risk of transmission threefold. Instead of 30%, you go down to 10%. So it’s another argument in the recent months or years to advocate for cytomegalovirus screening. Dr. Yves Ville, MD. But when you advocate for screening in pregnancy, especially recently, there is a lot of controversies. “you’re going to worry women for nothing.” Well, you know, if I’m 35 years old, I’m well educated and well off. I’ve got my first baby in a daycare center. I want to know if I have a 10% risk of getting this nasty infection, I think. What is the right way to go about cytomegalovirus? Dr. Anton Titov, MD. Should the kids, the first child, be screened regularly or the husband or only the pregnant woman? Dr. Anton Titov, MD. Only the pregnant woman needs cytomegalovirus screening. The child will have this cytomegalovirus virus. 80% of children in a daycare center pass CMV in their urine. 80%. And when they do pass the CMV in their urine, they do it for 2-3-4 years. There’s no point in screening children for cytomegalovirus. Dr. Yves Ville, MD. But only the pregnant woman needs cytomegalovirus screening. Dr. Yves Ville, MD. But you know, the effort is the first trimester. Again, the big step forward is that we’ve shown that after the first trimester, cytomegalovirus doesn’t matter. Screening for cytomegalovirus by the serology? Dr. Anton Titov, MD. Our research program focuses now on non-primary cytomegalovirus infection because there is no marker currently of non-primary cytomegalovirus infection. And it’s hard for pregnant women. So that’s important. Is there any new possibility that it will be included in any screening guidelines, or there isn’t? Dr. Anton Titov, MD. We’ve been pushing for this for years. The latest cytomegalovirus screening offer was two years ago, and it was not accepted by the health authorities. I think it’s a big mistake now. Dr. Yves Ville, MD. But things are moving so fast. And when you question health authorities, they convene independent committees to look at the problem. Medical second opinion. Then they look at the literature. And the literature on CMV – you can put in the trash bin everything that is older than four years. Because everything older than that will be a fable of things that are not accurate, that are mixing up different things. So the literature is polluted by the old studies. And still, those committees do not want to look only at recent research series because they need to have a deeper view. After all, they don’t know anything about the cytomegalovirus problem. So it’s hopeless. So cytomegalovirus can happen again, which could be a secondary infection. It is different from toxoplasmosis, which, if somebody had it before, they wouldn’t have it again. Exactly. You can get a non-primary cytomegalovirus infection. The risk factors for cytomegalovirus are not the same. They probably need to be sorted country by country. For example, in China, in Vietnam, in India, the number of babies proportion of babies born infected with cytomegalovirus, it’s about 4.3% and 1%. The same thing in France here, for example. Dr. Yves Ville, MD. But all of them are nearly born from non-primary cytomegalovirus infections in the mother because this population is immune, nearly 100% of the population nearly. Dr. Yves Ville, MD. But still, they do have the same rate of infection at birth. Whereas France, Holland, Great Britain, it’s about 50/50. So, for these countries, it’s different. We run a cytomegalovirus program at the moment with Vietnam. we need to find cytomegalovirus markers that can identify non-primary cytomegalovirus infection also early in pregnancy. Whether this is a primary or non-primary cytomegalovirus infection, the clinical problem is early in pregnancy, not afterward. So we’re making progress. All these recent advances have occurred within three, four years. So if a pregnant woman or a woman who is planning pregnancy and already has a child is seeing this conversation, what should she do? Dr. Anton Titov, MD. She should ask for cytomegalovirus serology (IgG/IgM testing). Medical second opinion. If she’s got a negative serology, no IgM, no IgG, she should be careful for the first three months. Medical second opinion. Then she should check once more at about 15 weeks. Medical second opinion. If she’s still negative for cytomegalovirus, she doesn’t need to worry about it. Cytomegalovirus can happen and it’s no problem. In the first trimester, when she checks, we find IgM and IgG – not IgM alone, IgM alone is nothing – IgG and IgM. That means she had a recent infection. You can be a bit more precise by asking for IgG avidity, which is a characteristic of the IgG. You sort the old antibodies from young antibodies, so to speak. And the IgG avidity will tell you if cytomegalovirus infection happened more than three months ago or less than three months ago. Medical second opinion. If it was less than three months ago, then she has to be considered as a high risk. She has to be put on valacyclovir. And then she could have either a CVS [chorionic villi sampling] at 13 weeks, just at the end of the first trimester, or an amniocentesis at 16 or 17 weeks. I do encourage people to do that earlier. So 13-14 weeks of pregnancy because if the CVS is negative at 13-14 weeks, you are sure there is no risk to the embryo. Medical second opinion. If you do an amniocentesis at 17 weeks, and it’s positive, you don’t know if cytomegalovirus infection just happened or if it happened before 14 weeks. So you still have this uncertainty of a month. So I’d rather be sure in the first trimester, just at the end. And if CVS is positive, then it’s again the antiviral treatment for this cytomegalovirus. What if the laboratory results return positive for IgG but not IgM antibodies? Dr. Anton Titov, MD. That means she is immune from before the pregnancy. Therefore, in theory, she’s potentially exposed to non-primary cytomegalovirus infection. Dr. Yves Ville, MD. But in non-primary cytomegalovirus, we don’t find the same risk factors. It’s not associated with the first child in the daycare nursery, etc. Most most likely, the non-primary cytomegalovirus is an effect of contamination through crowding. We found that in women, where you examine their way of life, they are much closer to many children and many people in the same house. So crowding is probably a risk factor more than anything else for non-primary cytomegalovirus, at least in France. Dr. Yves Ville, MD. But that has to be looked at epidemiologically in each country because we don’t know much about non-primary cytomegalovirus infections.
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