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Cytomegalovirus: What Every Pregnant Person Should Know

During pregnancy, your health care provider will go over lots of information, such as do’s and don’ts during pregnancy and when to come in for prenatal screenings and ultrasounds. One thing that you may not have discussed, however, is cytomegalovirus (CMV).


If you haven’t heard of CMV before, you’re not alone. Not many people know about it, yet most people have been infected with it by age 40. CMV is typically harmless, but it can be dangerous for your unborn baby when you’re pregnant.

Read on to learn more about CMV and how best to prevent it during pregnancy.

What is CMV?

CMV is a herpes family virus, which includes similar viruses like cold sores, chickenpox and genital herpes. Like other herpes viruses, the CMV can remain alive but inactive (dormant) within your body for life.

It’s rare for people to get symptoms after an initial infection, but if symptoms develop, they are usually mild and resemble cold-like symptoms. However, in folks who are pregnant or immunocompromised, the virus can have serious consequences.

Between 10 to 15% of newborns in the U.S. who are infected with congenital CMV develop symptoms, and in some cases, this infection can be life-threatening.

“The virus can affect many different organs in the body including the lungs, liver, kidneys, intestine and nervous system and can lead to long-term neurologic impairment, such as hearing and vision loss, and even death,” said Karen Volpe, MD, an infectious disease specialist with Banner Health Clinic in Greeley, CO. “For these reasons, it’s important for pregnant people to be aware of the risks of CMV infection.”

How is CMV spread?

Humans are the only source of CMV. Although the virus isn’t easily spread, it can spread person to person by direct contact. CMV is shed in body fluids, such as urine, saliva and breast milk.

If you’re pregnant and get CMV, the virus is primarily passed to your unborn baby in the placenta. “This occurs during pregnancy and is the most likely cause of fetal infection and is most likely to result in severe disease,” Dr. Volpe said.

CMV can also spread during childbirth or if your baby drinks infected breast milk. “However, these routes of transmission are unlikely to cause severe disease in healthy, full-term infants,” Dr. Volpe said. “Overall, the benefits of breastfeeding outweigh the minimal risk of acquiring CMV from breast milk.”

How do I know if I have CMV? What symptoms should I look out for?

Most children and adults who are infected with CMV don’t develop symptoms, but some may develop a fever, sore throat, tiredness, loss of appetite, nausea, vomiting, yellowing of the skin or eyes, abdominal pain, dark urine and light-colored stools.

Typically, you won’t be tested for CMV unless you have concerning symptoms, or a prenatal ultrasound indicates a birth defect suggesting congenital CMV infection.

Symptoms of possible CMV infection in infants include:

  • yellowing of the skin
  • tiredness
  • poor sucking during feedings
  • seizures
  • hearing loss
  • enlargement of the spleen and liver
  • microcephaly (small head size)
  • being small for gestational age

Some babies with congenital CMV who don’t show signs of CMV may still have or develop hearing loss. Hearing loss may occur at birth or develop later.

What should I do if I’m pregnant and have CMV?

If you become infected with CMV during pregnancy and you aren’t immunocompromised, typically your health care provider will focus on supportive care, such as careful monitoring and frequent testing, and relieving symptoms. Other medications, like antivirals, are not recommended as they have not been shown to reduce the ability to pass the infection onto the fetus. Your provider can review specific recommendations to help with symptoms.

“Pregnant people with CMV should remember that while CMV can cause severe and life-threatening disease in infants, congenital CMV infection only affects 0.5 to 1.3% of all infants,” Dr. Volpe said. “Only 8 to 10% of newborns with symptomatic CMV infection have a severe or life-threatening disease. Thus, congenital CMV, and especially severe disease in infants, is not very common.”

Will my baby need to be tested after birth?

Your baby may require testing for CMV if they show signs and symptoms consistent with congenital CMV or have abnormal neuroimaging consistent with CMV.

“Urine and saliva samples can be submitted for viral culture or molecular testing to confirm the diagnosis of CMV infection,” Dr. Volpe said.

In addition, children with congenital CMV should have regular hearing and vision checks. Catching problems early on allows you to do interventions that can greatly benefit them in the long run.

Is there anything I can do to prevent CMV?

The great news is that CMV infection is potentially preventable. There are several measures you can take to reduce your risk of becoming infected with CMV during pregnancy.

  1. Practice good hand hygiene. This is particularly important if you have a toddler at home or work in a school or daycare setting. Wash your hands often with soap and running water. This should be done especially after you’ve had close contact with young children, changed a diaper and handled toys, pacifiers or feeding utensils.
  2. Avoid kissing children under the age of 6 on the face and mouth. You can give plenty of snuggles and kiss them on the top of the head while you’re pregnant.
  3. Don’t share food, drink or toothbrushes with your little one. As tempting as it might be to finish off the food your toddler didn’t eat, stick to your own plate during pregnancy.
  4. Regularly sanitize and clean surfaces that come in contact with urine or saliva from children.


Cytomegalovirus, or CMV, sounds frightening, but it is also a preventable virus. Most people with CMV infection have no symptoms and are unaware that they have been infected.

Talk to your health care provider if you have any questions or additional concerns.

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