Cytomegalovirus (CMV) is a common virus that is insufficiently recognized by parents and even medical practitioners. Pregnant women are the most at risk as contracting CMV during pregnancy can result in transmission of the virus to the unborn child.
The incidence of CMV is 20 times higher compared to toxoplasmosis, another medical concern during pregnancy.
What is CMV?
Cytomegalovirus (CMV) is a virus from the herpes family that is transmitted by children under 6 years old. The virus spreads through body excretions including saliva, tears and urine.
It is most often benign however people whose immune system is weakened by a chronic disease or by drug treatment have a higher risk of developing severe symptoms of CMV.
More importantly, cytomegalovirus infection in pregnant women can lead to serious developmental disorders in the fetus.
What are the consequences of CMV?
Consequences of CMV for mommy:
Consequences of CMV infection for the pregnant woman are usually mild.
Consequences of CMV for baby:
Unborn children who contract CMV in utero risk may develop various symptoms from birth and during growth, including mental retardation, hearing problems or even complete deafness.
Congenital CMV:
When a baby is born with CMV, it is called congenital CMV. Some babies may develop health problems at birth while some babies will show symptoms later during their growth.
The CDC declared in May 2022 that CMV stands for the most common infectious cause of birth defects in the US. 1 out of 200 babies is born with congenital CMV and 1 out of 5 babies with congenital CMV will have symptoms or long-term health problems such as hearing loss.
Congenital CMV at birth can include but not limited to:
- Premature birth
- Low birth weight and Intrauterine growth restriction (IUGR) (the baby may have impaired growth in the womb, resulting in a smaller size than expected)
- Rash
- Jaundice
- Microcephaly (small head)
- Hepatosplenomegaly (larger liver and spleen than normal)
- Retinitis (damaged eye retina)
- Seizures
Congenital CMV during baby’s growth can include but not limited to:
- Lack of coordination or weakness
- Intellectual disability
- Hearing loss
- Vision loss
- Microcephaly (small head)
- Seizures
Is CMV contagious and how is CMV transmitted?
CMV can spread via different routes:
- Direct contact with infected body fluids: tears, saliva, urine or blood.
- From mother to baby inside the womb. CMV can cross the placenta and infect the developing fetus.
- From mother to baby when breastfeeding.
Certain situations pose a higher risk of exposure to the virus:
- Children under 6 years old: They have a higher likelihood of sharing the virus unknowingly while playing, kissing, or hugging, and subsequently transmitting it to their parents.
- Caring for a baby: Taking care of a baby, such as during diaper changes, increases the risk of exposure to CMV.
- Specific populations at risk: Childcare providers and parents whose older children attend pre-school while also planning for a new pregnancy.
Again, CMV infection usually presents mild to no symptoms and/or consequences at all to healthy individuals. Beside the fetus, CMV infection presents higher risk for immunodeficient people.
What are CMV Symptoms?
Detecting CMV can be challenging since its symptoms often resemble those of the flu, along with feelings of nausea – which is quite common during a pregnancy.
How to diagnose CMV?
CMV can be detected with a blood test during which 2 types of antibodies are evaluated:
- IgM antibodies – produced by the body in response to an acute CMV infection. Detecting IgM antibodies in a blood test suggests a recent/active CMV infection.
- IgG antibodies – produced by the body after infection and staying in the bloodstream for a longer duration. Detecting IgG antibodies suggests past exposure/infection to CMV.
If a blood test performed before a pregnancy reveals IgG, it could mean there are enough antibodies to protect both the mother and the fetus during the pregnancy.
If blood tests conducted during pregnancy do not detect any IgM or IgG antibodies up to 12 weeks, it is generally considered to be a reassuring outcome.
What are CMV treatment? How to protect yourself from CMV?
At present, there is no available vaccine or cure for CMV. There is however a treatment to help reduce the severity of symptoms and complications caused by CMV virus.
It is crucial to consult with healthcare professionals for guidance and appropriate management of CMV-related symptoms, as they can provide the most up-to-date information on available treatments and interventions.
How to prevent CMV:
Recent research has demonstrated that the period of greatest risk for the mother or mother-to-be lies within the two months prior to pregnancy and throughout the first trimester of pregnancy.
During this period, we recommend parents to limit exposure to children’s body fluids:
- When comforting a child, avoid contact of your mouth with the child’s tears. Instead of kissing their cheeks, kiss the head.
- Wash hands thoroughly after changing the baby or whenever you’re in contact with urine or feces.
- Avoid sharing food with baby. Don’t use the same glass or cutlery and refrain from finishing baby’s leftovers.
We understand these pieces of advice may seem difficult especially for parents of young children but it is only temporary until the most critical period of CMV exposure is over.
