Diagnosis of CMV in mother and fetus

Posted by Doctor Specialist I Nguyen Van Hung - Obstetrics Department - Vinmec Times City International Hospital

Infection with CMV virus (Cytomegalo) can take place during pregnancy. Therefore, if the mother is infected with CMV as soon as possible, the baby will have a high risk of health problems and birth defects, especially in the first 3 months of pregnancy. In addition, in a small number of cases, babies can be infected with CMV virus during labor or while breastfeeding. Therefore, the diagnosis of CMV for mother and fetus is very important for the prevention and treatment of the disease.

CMV virus can be transmitted from mother to baby during pregnancy. Most babies who get CMV from their mothers after birth do not present any health risks. However, some children have birth defects caused by the virus. Therefore, the diagnosis is very important to prevent malformations and health for mother and baby.
Primary diagnosis of CMV infection during pregnancy:
When the test appears positive for CMV IgG antibodies when previously negative or with positive IgM (+) and low avidity IgG (+) antibodies ; In the absence of primary infection, serological testing may not be required; For other viruses such as rubella, the presence of IgM is often used to diagnose primary or recent infection, but CMV is not the same. Because CMV IgM can persist for many months after primary infection, IgM can also appear immediately after reinfection, some cases of cross-reactivity with IgM with other viral infections or IgM can also be provoked by CMV infection. nonspecific viruses. Therefore, the test requires specific IgG along with IgM. To determine when pregnant women are infected with CMV virus before or during pregnancy, it is necessary to test IgG avidity as follows:
If low avidity index (<30%) means recent infection (within 3 months) ; Cases with high avidity index (>60%) mean infection for > 3 months or because of reinfection. It is often difficult to diagnose non-primary CMV infection, because elevated IgG cannot confirm CMV reinfection. Therefore, it is only necessary to confirm fetal transmission and reinfection by CMV-PCR analysis of amniotic fluid.

To diagnose CMV for pregnant women, it is necessary to perform the following methods:
Amniocentesis: Diagnosis of CMV infection requires PCR of amniotic fluid to find CMV DNA. Ideally, amniocentesis is at least 8 weeks after maternal CMV infection and gestational age >20 weeks. There can be negative results, so a risk factor for false negatives that need to be considered is the time from mother's CMV infection to amniocentesis <8 weeks and gestational age <18 weeks.

3.1. Prognosis of CMV-infected fetus Prognosis of poor pregnancy outcomes and outcomes includes timing of CMV infection, fetal abnormalities, and subtype of CMV infection. CMV can be divided into 3 groups as follows:
Asymptomatic CMV infection group: This is the group without abnormal signs on ultrasound, brain MRI has normal results, biological and platelet indicators are also normal. normal. Therefore, in general, the asymptomatic group with CMV infection has a good prognosis. CMV virus infection group with mild symptoms or moderate symptoms: On fetal blood tests alone, abnormal biomarkers but no brain abnormalities on ultrasound or abnormal echocardiography in the intestines, brain dilation slight loss. Therefore, this group needs further follow-up with ultrasound and MRI for prognosis. Antiviral treatments are still being evaluated, but their application is still being researched. The option to terminate the pregnancy can be discussed. Group infected with CMV virus with severe symptoms: For this group, brain abnormalities were seen on ultrasound such as fetal microcephaly, wide ventricle dilation, intracranial hemorrhage, and cortical retardation. This group has a poor prognosis and can advise termination of pregnancy. 3.2. Management of pregnancy with CMV infection There are no randomized controlled clinical trials, so treatment of CMV infection with high-dose valacyclovir should only be used in the study. At the same time, there is currently no vaccine to prevent CMV. Therefore, treatment to reduce the risk of infection is as follows:
Behavioral modification to reduce direct contact with saliva or urine of young children with CMV infection; Prevention of CMV virus infection by avoiding sharing utensils, eating and drinking. To prepare for a healthy pregnancy and diagnose CMV, both husband and wife should have their reproductive health checked 3-5 months before becoming pregnant.
The wife should:
Get vaccinated before pregnancy (especially against rubella because rubella in pregnancy is extremely dangerous ) Genetic testing to screen for genetic diseases before pregnancy Check for secondary infections In particular, women over 35 years of age, if they want to become pregnant (especially if they have never been pregnant), will have to have a very detailed health check because pregnancy at this age often problems: Ovarian failure, premature birth, higher risk of birth defects, placenta previa, preeclampsia. The husband should:
Check reproductive health, detect diseases of testicular atrophy, physiological weakness, weak sperm... Sexually transmitted diseases, especially those that cannot be cured, are extremely dangerous. Vinmec currently has many comprehensive health care programs for couples, pregnant mothers and their unborn babies, including basic pre-marital examination packages, advanced pre-marital examination packages, and maternity packages. . Vinmec has a team of experienced doctors in the fields of obstetrics and gynecology, IVF, stem cells, gene technology, capable of synchronously and comprehensively deploying the most advanced assisted reproductive techniques today.
For specific information about fertility and maternity packages at Vinmec, please contact the hospitals and clinics of Vinmec health system nationwide.