What is congenital CMV and how can it affect babies?

Cytomegalovirus (CMV) is a very common, usually innocuous, virus. In healthy individuals, it rarely causes symptoms. Symptoms may include fever, malaise, sore throat, swollen lymph nodes and loss of appetite.

The virus is transmitted through contact with saliva, urine and other body fluids. It can infect people at any age, but children ages one to three are most commonly infected. When a baby is infected in utero, it’s called “congenital CMV.”

“The biggest concern is when the virus is first contracted during pregnancy, it can infect the baby and cause significant problems such as hearing and vision loss and learning disabilities,” said Shelley J. White-Corey, RNC, WHNP-BC, assistant professor at the Texas A&M Health Science Center College of Nursing.

According to the Centers for Disease Control and Prevention, it is the most common congenital infection, causing more disability than Down syndrome, fetal alcohol syndrome or spina bifida. Estimates are 30,000 U.S.-born children are affected each year. Of these, 8,000 will suffer permanent disabilities, and 400 will die from the infection.

If a pregnant woman is having symptoms, blood tests can identify a primary CMV infection. Abnormalities found on ultrasound can be signs of possible fetal infection. In these cases, an amniocentesis (test of the fluid surrounding the baby) may be done.

“The good news is that 90 percent of infected newborns have what is called ‘silent’ CMV, meaning they have no symptoms and are expected to lead normal, healthy lives,” White-Corey said. “The other 10 percent should be monitored closely to provide early intervention for problems.”

So if you’re pregnant now, what can you do?

The most important thing is to avoid infection by observing good hand-washing technique, especially after changing a diaper, wiping a runny nose or handling children’s toys, White-Corey says. Avoid contact with saliva by not sharing food, drinks or eating utensils with small children or receiving “sloppy” kisses. Clean toys, countertops and any other surfaces that may come into contact with children’s urine or saliva.

While the Centers for Disease Control and Prevention (CDC) do not recommend routine screening for CMV during pregnancy, if you are planning to become pregnant, talk with your doctor about blood tests to determine if you have ever been infected with CMV. Antibody testing can differentiate between active, primary infections and inactive (or dormant) infections. Primary infections during pregnancy are most risky for the unborn baby.

For more information, visit the CMV Action Network online.

— Blair Williamson