CYTOMEGALOVIRUS (CMV) DURING PREGNANCY

General Information

Cytomegalovirus (CMV) belongs to the herpesvirus family. It is a DNA virus and a common virus that can infect anyone. Many people may not be aware that they have the virus, and it rarely causes problems in healthy individuals. In pregnant women and people with weakened immunity, it can cause problems. Pregnant women who develop an active CMV infection during pregnancy can pass the virus to the baby, which may present symptoms. CMV spreads from person to person through bodily fluids such as blood, saliva, urine, semen, and breast milk. A person transmits the virus only when it is active (when acquiring the virus for the first time or when the virus reactivates due to weakened immunity).

Pregnant Women

Generally healthy pregnant women do not have a specific risk for CMV infections. Infected pregnant women rarely show symptoms, but the development of their baby may be at risk for congenital CMV disease. Transmission from mother to baby is 30-50%. Of the infected babies, only 10-15% show signs of congenital CMV infection after primary maternal infection. The incidence of congenital CMV infection is about 0.2-2.5%.

Signs and Symptoms

• Primary CMV infection can cause a fever of unknown origin. Symptoms become apparent 9-60 days after primary infection.
• Pharyngitis may be present.
• Examination of the tonsils may reveal crepitant rales.
• The spleen and lymph nodes may enlarge, so CMV is included in the differential diagnosis of pathologies causing lymphadenopathy.

The majority of healthy adults, including pregnant women, do not have symptoms. Others may experience: fever, sore throat, fatigue, enlarged glands, muscle pain, loss of appetite, joint stiffness.

Signs in Infants

In newborns, CMV can lead to anomalies seen on ultrasounds during the prenatal period.

Many newborns show no signs of CMV at birth and have no ongoing issues.

If there are suspicions of a newborn being affected by CMV, appropriate tests will be conducted. These tests include blood, saliva, urine tests, ultrasound, and hearing tests. The child will have more tests after the age of 12 to ensure there are no problems, such as an EKG to check that the heart is in good condition.

1 in 10-15 newborns with CMV has symptoms such as microcephaly (small head), small red spots (petechiae), jaundice, enlarged liver and spleen, hearing loss, and calcium deposits in the brain. Some children may face developmental issues like physical damage, seizures, attention disorders, hyperactivity, autism, visual impairments.

Diagnosis

In suspected CMV patients, serological tests (IgG and IgM antibodies) are performed.

In the acute phase, IgM is positive, and IgG is negative. IgM can remain positive for up to 9-12 months after acute infection.

The IgG antibody avidity test is very useful for differential diagnosis between acute and chronic infections. In acute forms, IgG antibody avidity is low, and in recurrent infections or reactivated infections, IgG antibody avidity is high.

Diagnosis of Congenital Infections

The best test for congenital diagnosis is the detection of the virus in amniotic fluid through culture or PCR. Amniocentesis assesses 12 out of 13 fetuses with congenital infection.

Ultrasound is valuable in assessing fetal problems. Ultrasound findings include: placentomegaly, intrauterine growth restriction (IUGR), microcephaly, ventriculomegaly, periventricular calcifications, isolated serous effusion, and echogenic areas.

Management

Three types of exposure reduction are:

1. Do not share food, drinks, eating utensils with young children, especially infants.
2. Do not kiss young children on or around the mouth.
3. Wash hands after coming into contact with babies, runny noses, and oral secretions.

Healthy individuals infected with CMV who do not show symptoms usually do not require medical treatment.

Antiviral treatment is used only in individuals with compromised immunity who have eye infections and life-threatening diseases.

There is no vaccine to prevent CMV infection.