Cytomegalovirus and your baby

Cytomegalovirus (CMV) is a herpes virus. This is a large group of viruses that can cause different kinds of diseases and health problems. Most people get CMV at some point in their lives, most often during childhood.

CMV is the most common congenital infection in the United States. Congenital means that it’s something a baby’s born with. Each year about 1 in 150 babies (less than 1 percent) is born with CMV. About 8,000 children each year develop lasting health problems caused by CMV.

You can pass CMV to your baby at any time during pregnancy. It’s more likely to cause problems for your baby if it happens in the early part of pregnancy. You also can pass CMV to your baby during labor and birth and during breastfeeding. If your baby gets the virus during these times, he’s less likely to have health problems than if he gets the virus during pregnancy.

What problems can CMV cause in babies?

Most babies born with CMV don’t have serious health problems from the virus. Eight in 10 babies born with CMV (80 percent) never have symptoms or problems caused by the infection.

About 15 in 100 babies born with CMV (15 percent) develop one or more disabilities during the first few years of life. These disabilities can include:

  • Hearing loss
  • Intellectual disabilities (problems with how the brain works that can cause a person to have trouble learning, communicating, taking care of himself and getting along with others)
  • Vision loss

How do you know if your baby has CMV?

If you’re pregnant and have CMV, you can have prenatal tests to see if your baby has CMV.

After birth, your baby’s health care provider can test your baby’s body fluids within 3 weeks of birth to check for CMV. Body fluids include urine, saliva and blood.
Most babies born with CMV appear healthy. But about 1 in 10 infected newborns (10 percent) have signs and symptoms of CMV at birth. These include:

  • Enlarged liver or spleen
  • Jaundice (yellowing of the skin and eyes) or liver problems
  • Low birthweight (when a baby weighs less than 5 pounds, 8 ounces)
  • Premature birth (birth that happens too early, before 37 weeks of pregnancy)
  • Feeding problems
  • Rash
  • Seizures
  • Small size
  • Swollen lymph nodes

Older babies and children usually don’t have CMV symptoms. But some may have:

  • A sore throat
  • Fever that lasts for a few days
  • Swollen glands
  • Fatigue (extreme tiredness)

Call your baby’s health care provider if you think your baby may have CMV.

How are babies born with CMV treated?

Even though most babies aren’t harmed by CMV, all babies born with the virus need regular hearing and vision tests.

Babies born with CMV may be treated with antiviral medicines. These medicines kill infections caused by viruses. This treatment usually happens in a hospital.

More information

National CMV Foundation

See also: Cytomegalovirus and pregnancy

Last reviewed: April, 2013