Cytomegalovirus: What You Should Know About CMV in Pregnancy

Luis Martin Gomez, MD, MsCE, is board-certified in maternal-fetal medicine and obstetrics and gynecology. He specializes in high-risk pregnancies and practices at Perinatal Associates of Northern Virginia and the Inova Health System.

Cytomegalovirus (CMV) may be the most common virus you’ve never heard of. For most people, the virus is a minor inconvenience — if you notice it at all. But for a developing baby, the infection can be serious.

Congenital CMV — when babies are infected in the womb —is the most common infectious cause of birth defects. Learning about the virus is the best way to protect your growing baby.

What is CMV?

CMV is very common. In the U.S., almost a third of children have been infected by their fifth birthday. By age 40, more than half of adults have been infected.

Many of them didn’t even know it. Most people have no symptoms from CMV infection. Those that do, usually have mild cold-like symptoms, such as fever, sore throat and a runny nose.

If you’re infected during pregnancy, you can pass the virus to your developing baby without being aware— especially if you’ve never been infected with it before. 

Many babies born with congenital CMV look healthy at birth. But some experience symptoms, including:

• Jaundice (yellow skin and eyes)
• Small head
• Rash
• Low birth weight
• Enlarged spleen or liver
• Seizures

Health Problems From Congenital CMV

Not all babies with congenital CMV develop health problems. But as many as 1 in 4 will develop long-term issues, such as:

• Hearing loss
• Developmental delays
• Vision problems
• Seizures
• Weakness or coordination problems
• Death

Hearing loss is the most common complication of CMV in babies. Sometimes, it develops later in babies who had normal hearing at birth.  

If your baby has signs of CMV, doctors can test saliva or urine to confirm the infection.

There’s no specific treatment for congenital CMV. But some recent research suggests that treating infected newborns with medications called antivirals might make long-term problems less severe. 

How to Prevent Cytomegalovirus During Pregnancy

Researchers are still working to develop a vaccine for CMV. In the meantime, you can take steps to prevent infection and reduce the risk to your developing baby:

• Wash hands often. Good hand hygiene is one of your best defenses.
• Avoid kisses and other close contact with friends and family while you’re pregnant.
• Maintain your distance from anyone who has cold symptoms.
• Avoid contact with saliva and urine from babies and children — in infected kids, these fluids can contain a lot of the virus. Don’t share food or utensils with children, and wash your hands after changing diapers.
• Do not miss scheduled ultrasound exams during your pregnancy. These scans can identify signs of congenital CMV early. If doctors suspect CMV, they can develop a plan for managing your pregnancy and testing your baby after birth.

Unfortunately, screening for CMV isn’t part of routine care during pregnancy. But women can request tests to find out if they’ve been exposed in the past — or have been recently infected.

If you’re pregnant or planning to become pregnant, talk to your doctor about CMV testing, and discuss how you can lower your risk. Find an obstetrics and gynecology provider.