June 2025

Congenital CMV Explained: How it Spreads and Why Early Testing Matters with Dr. Shannon Murphy

Cytomegalovirus (CMV) is a surprisingly common virus that affects people of all ages. While it often goes unnoticed in healthy individuals, CMV can pose significant health risks to newborns if transmitted during pregnancy. Known as congenital CMV when passed from parent to baby, this virus is a leading cause of hearing loss and developmental delays in infants. Awareness, early detection, and timely care are key to minimizing its impact.

What is CMV?

CMV (cytomegalovirus) is a common virus that can infect people of all ages. Most healthy individuals who contract CMV experience no symptoms, but it can be dangerous for newborns and people with weakened immune systems.

How CMV Spreads

It spreads through bodily fluids like saliva, urine, blood, and breast milk. In pregnant individuals, CMV can be passed to the baby, potentially leading to congenital CMV, which may cause hearing loss or developmental delays.

How CMV is Diagnosed?

If indicated, your pediatrician may test your newborn for CMV. Initial testing is done with a cheek swab. Further testing may be indicated if the initial test is positive. Early detection is important to facilitate timely management and interventions to best support the child's health and development, as well as continued research.

Though CMV is common, congenital CMV is not always widely understood. By learning how the virus spreads and recognizing the importance of early testing, parents and caregivers can play a critical role in supporting infant health. If you’re concerned about CMV or have questions about testing, speak with your pediatrician—they can guide you through the next steps and provide personalized support.