• Français


Maternal pregnancy complications


Cytomegalovirus (CMV) is a virus that belongs to the same family as herpes.

CMV infection usually causes few or no symptoms in children and adults but may pose a risk to pregnant women.

About one in three children has contracted CMV before the age of five, and 50% to 80% of adults under 40 have the virus. When someone has a CMV infection for the first time (primary infection) at any age, they develop antibodies.

However, since there are several strains of this virus, these antibodies will not necessarily provide protection against future infections. In addition, sometimes the virus can reactivate. This phenomenon, called non-primary infection, is usually asymptomatic.

Cytomegalovirus and pregnancy

A CMV infection (primary or non-primary) in pregnant women can be transmitted to the fetus and cause various problems in the unborn child such as:

  • Deafness
  • Intellectual disability
  • Vision loss or blindness
  • Various developmental disorders

CMV is the most common cause of infection in utero (in the uterus) and occurs in 0.2-2.2% of all live births. Fortunately, 80% of infected children are asymptomatic and will not develop any long-term health problems.


CMV is spread through contact with body fluids, mainly urine and saliva.

Recommendations for pregnant women

  • Do not share utensils or glasses with children
  • Avoid kissing your child on the mouth (or cheeks)
  • Do not share your toothbrush
  • Regularly wash your hands well with soap and water, especially after doing any of the following:
    • Helping a child blow their nose
    • Changing a diaper
    • Feeding a child
    • Holding children’s toys

Symptoms to watch for

It is common for CMV infections to go unnoticed. Symptoms that may be experienced are similar to those of a prolonged flu:

  • Fever
  • Sore throat
  • Fatigue
  • Swollen glands

Tests and procedures

Screening for CMV is not part of a regular medical checkup during pregnancy.

If there are risk factors in your life, if you have been in contact with a sick child, or if you have symptoms similar to CMV, your doctor may order blood tests to look for IgG and IgM antibodies to the virus and may refer you to a specialist to assess pregnancy risks.

If the assessments carried out suggest a possible CMV infection while you are pregnant, an ultrasound may be performed to try to detect any fetal abnormalities related to the virus.

Your doctor may also suggest that you do an amniocentesis to confirm the diagnosis.

Treatment and follow up

There are no treatments that have been shown to offer protection for pregnancies. However, experimental treatments (immunoglobulins, antivirals, vaccines) are being evaluated.

In children, diagnosis and early treatment with valganciclovir can improve prognosis.

Resources and useful links

National Center for Immunization and Respiratory Diseases.
Identifying Congenital Cytomegalovirus (CMV) Early in Life: Information for Healthcare Providers


Page by

Dre Isabelle Boucoiran et Marie-Pierre Gagné, inf. clinicienne

About this page
Updated on 1/25/2021
Created on 1/25/2021
Alert or send a suggestion

Every dollar counts!

Thank you for your generosity.

It is thanks to donors such as you that we are able to accelerate research discoveries, to heal more children every year and to continue to offer world-class care.

It is also possible to give by mail or by calling toll-free

1-888-235-DONS (3667)

Contact Us

514 345-4931


© 2006-2014 CHU Sainte-Justine.
All rights reserved. 
Terms of Use,  Confidentiality,  Security


All information contained within the CHU Sainte-Justine site should not be used as a substitute for the advice of a duly qualified and authorized medical practitioner or any other health professional. The information provided on this site is intended for educational and informational purposes only.

Consult your physician if you feel ill or call 911 for any medical emergency.

CHU Sainte-Justine