Cytomegalovirus (CMV) and Pregnancy Risk

Cytomegalovirus (CMV) is a common herpes virus that is spread through body fluids such as saliva, tears, blood, urine, breast milk, semen, and vaginal fluids. More than half of all people have been infected by age 40. The infection remains in the body for life. Fever, sore throat, and other symptoms can occur, though many people have no symptoms.

When contracted during pregnancy, CMV infection can affect the fetus. This occurs in about one in 200 pregnancies and about 20% of these congenital CMV infections will cause birth defects. Occasionally, CMV can lead to hepatitis or mononucleosis. Antivirals can be used if necessary, and experts continue to work on a vaccine to one day prevent CMV.

Symptoms

Most CMV infections have no symptoms. When CMV does cause symptoms, they often are similar to those seen with many common illnesses. These symptoms can include:

• Sore throat
• Swollen lymph nodes
• Fever
• Fatigue or weakness
• Muscle aches or joint pain
• Night sweats
• Weight loss

Because these same symptoms can be found in many other illnesses, you may have CMV or have become infected at some point in your life and not have been diagnosed with the virus. In non-pregnant people and people with healthy immune systems, CMV infection is usually not a concern.

Congenital CMV

Congenital CMV occurs when infection in a pregnant person passes to the fetus. It is the most common viral infection to do so. CMV can lead to birth defects, typically affecting one in five babies born with congenital CMV.

The infection can cause temporary and permanent disabilities including:

• Hearing loss
• Vision loss
• Seizures
• Liver problems (including jaundice)
• Spleen problems
• Low blood platelet levels
• Purple spots on the skin (purpura)
• Lung problems
• Low birth weight and small head size
• Intellectual disabilities

Congenital CMV only occurs during pregnancy. If CMV occurs after birth, there is no risk of congenital complications. While routine CMV testing is not needed, your healthcare provider may recommend amniocentesis to check for CMV if ultrasound images show concerning changes.

Diagnosis

Cytomegalovirus can be diagnosed using a simple blood test that looks for antibodies against the virus or by measuring actual CMV viral levels in the blood. While it is easy to detect this virus, it is difficult to pinpoint the time at which a person has been infected.

Saliva or urine tests are preferred when testing for CMV in newborns.

Treatment

There is no known cure for CMV. Several medications for CMV treatment are under study, including vaccines that show promise in preventing infection. Current options include:

• Cytogam (cytomegalovirus immune globulin intravenous), a drug that can be given to pregnant people to limit congenital CMV impacts.
• Cytovene (ganciclovir), to treat a newborn with CMV after birth
• Valcyte (valganciclovir), available to prevent CMV infection in people diagnosed with human immunodeficiency virus (HIV) or who are at risk due to organ transplant.

Treatment and therapy also may be needed for a complication of CMV, or for an underlying health condition. For example, infectious mononucleosis can occur in otherwise healthy people who aren't at risk for other CMV complications. Older adults may be at additional risk.

Prevention

You can take steps to prevent CMV infection with careful hygiene practices, such as handwashing for at least 15 to 20 seconds, especially after changing diapers. Most precautions focus on child care, including keeping toys clean or taking care after wiping a child's nose.

Don't share food and drink with others and keep countertops and other surfaces clean. Talk with your healthcare provider if you have specific concerns about CMV exposure or spread.

Summary

Cytomegalovirus (CMV) is a common type of herpes virus that infects more than half of all people by age 40. It typically presents no serious risk to healthy people, but it can cause complications in older people or those with compromised immune systems. Mild symptoms can occur but some people do not experience any at all.

Congenital CMV, however, can lead to birth defects in about 20% of babies who experienced a fetal infection transmitted during pregnancy. It's a common cause of hearing loss but also leads to other lifelong health issues. Researchers continue to work on vaccines and other treatments, but prevention currently relies on careful hygiene practices.