Dr. Tran Thi Thuy Hang, Head of the Otolaryngology Department at Tam Anh General Hospital in Ho Chi Minh City, explained that CMV is a herpes virus that can cause infections such as chickenpox and shingles. When a pregnant woman contracts CMV, the virus can be transmitted through the placenta to the fetus. Newborns infected with CMV often experience hearing and sensory nerve impairment. Hearing loss can occur in one ear and then spread to the other, potentially progressing from mild to severe within the first two years of life, affecting speech and language development.

The risk of birth defects is higher if the mother contracts rubella during the early stages of pregnancy. Children infected with this virus may experience deafness, congenital heart disease, cataracts, encephalitis, intellectual disability, and epilepsy. Rubella is transmitted through direct contact or respiratory droplets from the nose and throat. After inhalation, the virus multiplies in the mucous membranes of the respiratory tract and cervical lymph nodes before spreading to other organs through the bloodstream. The infection period lasts from about 8 days before to 8 days after the rash appears.

Individuals infected with rubella or CMV often exhibit mild flu-like symptoms, including fever, nasal congestion, sore throat, muscle aches, and fatigue, which can be easily overlooked.

For example, An's mother did not receive the full rubella vaccination before pregnancy and contracted the disease during her second month of pregnancy. Newborn hearing screening diagnosed An with congenital deafness, despite being born full-term. Blood tests revealed a rubella infection contracted in utero, and a cochlear implant was recommended at 12 months of age.

An received a cochlear implant at Tam Anh General Hospital at 18 months old. Six months later, she is working with a specialist to learn to recognize and distinguish sounds.

Dr. Hang (left) during a cochlear implant surgery. Photo: Tam Anh General Hospital

Dr. Hang (left) during a cochlear implant surgery. Photo: Tam Anh General Hospital

Besides viral infections, other factors contributing to congenital deafness include maternal infections like toxoplasmosis and herpes simplex, alcohol consumption during pregnancy, uncontrolled gestational diabetes, and preeclampsia. Early detection of congenital deafness is crucial to avoid missing the critical period for language development. The optimal time for cochlear implantation to restore hearing and facilitate normal development is between one and two years of age.

Dr. Hang recommends that women planning to become pregnant receive vaccinations for rubella, chickenpox, influenza, and hepatitis B to prevent infections during pregnancy. Pregnant women should adhere to regular prenatal checkups and undergo screening tests for rubella, CMV, and toxoplasmosis if deemed necessary. After birth, parents should participate in newborn hearing screenings, monitor their child's language development milestones, and be aware of any unusual signs. If any suspicious signs are observed, parents should consult an otolaryngologist for prompt diagnosis and treatment.

Uyen Trinh