CMV in Newborns

Key points

  • When a baby is born with cytomegalovirus (CMV) infection, it is called congenital CMV.
  • CMV is most common infectious cause of birth defects in the United States.
  • Most babies with congenital CMV never show signs or have health problems, but some do at birth or develop them later.
Newborn baby in hospital with mother.

How does it spread

CMV is spread through contact with body fluids.

Young children often have CMV

Young children are a common source of CMV. By 5 years old, 1 in 3 children has been infected with CMV, but they usually do not have symptoms. High amounts of the virus can stay in a child's body fluids like saliva and urine for months after the infection.

Teacher sitting in a circle with elementary age children playing the recorder.
If you are often around young kids, you are more likely to get CMV

You can spread CMV during pregnancy

If you are pregnant and get infected with CMV, you can pass the virus to your baby during pregnancy. The virus crosses from your blood into your placenta. This can happen when you are infected with CMV for the first time or again during pregnancy. Most people with CMV infection have no symptoms and aren’t aware that they have been infected.

Signs and symptoms

About 1 in 200 babies is born with congenital CMV. About 1 in 5 babies with congenital CMV will have birth defects or long-term health problems, like hearing loss.

Signs at birth

Some babies with congenital CMV infection have signs at birth, such as:

  • Rash
  • Jaundice (yellowing of the skin or whites of the eyes)
  • Microcephaly (small head)
  • Low birth weight
  • Hepatosplenomegaly (enlarged liver and spleen)
  • Seizures
  • Retinitis (damaged eye retina)

Long-term problems

Some babies with signs of congenital CMV infection at birth can have long-term health problems, such as:

  • Hearing loss
  • Developmental and motor delay
  • Vision loss
  • Microcephaly (small head)
  • Lack of coordination or weakness
  • Seizures

In the most severe cases, CMV can cause pregnancy loss.

Hearing loss

Hearing loss is common in newborns with CMV. Some babies can have hearing loss at birth or can develop it later. This can happen even to babies who passed the newborn hearing test or didn't have any other signs at birth. Babies with congenital CMV infection should have regular hearing checks.

Early therapies can help children diagnosed with hearing loss.

Young child receiving hearing checks from doctor.
The earlier kids start services, the more they can benefit from them.

How to prevent it

Parents, childcare providers, and pregnant people can lower their chance of getting CMV by reducing contact with saliva (spit) and urine from babies and young children.

While there are no ways to eliminate your risk, you can reduce your chance of getting and spreading CMV. Make sure you:

  • Do not share food, utensils, cups, or pacifiers with a child.
  • Wash your hands with soap and water after changing diapers or helping a child to use the toilet.

What tests exist

In newborns:

Congenital CMV infection can be identified by testing a newborn baby’s urine (preferred), saliva, or blood. These tests must be done within 2 to 3 weeks after the baby is born to confirm if the baby has congenital CMV.

If you are pregnant:

It is not recommended that doctors routinely test pregnant people for CMV infection. This is because lab tests cannot predict which developing babies will become infected with CMV or have long-term health problems.

Early treatments may help

Babies who show signs of congenital CMV infection at birth can be treated with medicines called antivirals. These may decrease the severity of hearing loss. Babies who get treated with antivirals should be closely watched by their doctor because of possible side effects.

Valganciclovir is an antiviral medication that might improve hearing and developmental outcomes. It can have serious side effects and has only been studied in babies with signs of congenital CMV infection. There is limited information on the effectiveness of valganciclovir to treat infants with hearing loss alone.


Parent to Parent Support Network

The National Congenital CMV Disease Registry assists nearly 600 families affected by CMV by providing a way to exchange information and by offering help and support to one another.