OSCE station SP station Congenital CMV
A communication station for neonatal and paediatric trainees: explaining congenital CMV with isolated hearing loss to a parent, and talking through valganciclovir and follow-up.
You are the neonatal registrar. Amira was born at 39 weeks’ gestation and is now 3 weeks old. She did not pass her newborn hearing screen in her right ear. A saliva CMV PCR was positive, and a urine CMV PCR taken on day 6 has confirmed congenital CMV (cCMV).
Her physical and neurologic examination, growth parameters (including head circumference), complete blood cell count, liver function tests and cranial ultrasonography are all normal. Diagnostic ABR shows sensorineural hearing loss in the right ear; the left ear is normal. The paediatric infectious diseases team has reviewed her and is happy for the family to consider treatment.
Task: Explain the diagnosis to her mother, discuss the treatment option and the follow-up Amira will need, and answer her questions. You do not need to take a history.
Suggested time: 10 minutes
Layla Hassan, 31, Amira’s mother. She also has a 3-year-old son at nursery. She is tired, anxious and tearful when she talks about blame, and she has been reading online.
Opening line: “The nurse said it’s a virus — CMV? I’d never even heard of it. Is that why she failed the hearing test?”
Raise these if the candidate has not covered them:
- “Did I do this to her? Is it because of my son’s nursery?”
- “Is she going to go deaf? Will the other ear be affected?”
- “What is the medicine, and does she have to have it?”
- “Is it safe? What are the side effects?”
- “What happens after that — how often will she be checked?”
- “Will this happen again if we have another baby?”
Look confused if jargon goes unexplained. You lean towards treatment if it is explained clearly, but you want to know it is your choice.
Questions
How would you explain the diagnosis to Mrs Hassan?
Show model answer
- CMV infection is common. Congenital CMV means the virus was passed to the baby before birth; finding it in the urine within the first 21 days after birth shows infection before birth.
- Amira has cCMV with isolated SNHL: the hearing change in one ear is the only sign found. Her examination, blood tests and head ultrasound are normal.
- Explained in plain words, in small chunks, checking what she already knows and what she has understood.
“Did I do this to her?” How do you respond?
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- Acknowledge the feeling and avoid any blame.
- CMV infection is common. It spreads through close contact with bodily fluids such as saliva and urine, and young children shed the virus for prolonged periods — ordinary family life, not anything she did wrong.
“Is she going to go deaf? Will the other ear be affected?”
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- cCMV can cause fluctuating hearing thresholds, which may improve but more commonly decline over time.
- Hearing changes may be asymmetric, and late-onset changes can occur, so each ear will be checked separately over time.
- Be honest about the uncertainty: no false reassurance, and no prediction of deafness as certain.
“What is the medicine, and does she have to have it?”
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- Valganciclovir, by mouth, in 2 doses a day (32 mg/kg/d divided in 2 doses), for 6 weeks.
- It may be offered: treatment started by 13 weeks after birth has shown benefit on hearing outcomes, but there are insufficient data to recommend routine treatment. It is considered case by case with a paediatric infectious diseases expert.
- In the nonrandomised CONCERT study, hearing thresholds declined by a mean of 13.7 dB without treatment and improved by a mean of 3.3 dB with treatment.
- The decision is hers, made together with the team.
“Is it safe? What are the side effects?”
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- The main recognised effect is a low neutrophil count (a type of white blood cell), which can also come from the CMV infection itself.
- Blood tests: neutrophils weekly for 6 weeks, at week 8, then monthly until the end of treatment; liver tests (transaminases) monthly until the end of treatment.
- If the count falls significantly, treatment is paused until it recovers, or a growth-factor injection can be used.
- Fertility and cancer effects have been reported in rodents, but not in human studies.
“What happens after that — how often will she be checked?”
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- Hearing checks in each ear. For children with cCMV and no recognised hearing changes, the schedule is: initial audiology evaluation by 3 months, then screening at 4, 6, 9, 12, 15, 18, 24 and 30 months, annually from 4 to 6 years, and at 8 and 10 years. Because Amira has SNHL, her audiology and ENT team will set her own schedule.
- Eye examination, then annual ophthalmology review. Paediatric infectious diseases review annually to age 2 years. Neurodevelopmental assessment at 12 months, and at 24 months if she is treated.
- Referral to an early intervention programme offered.
- Seek prompt review if the parents are worried about her hearing, or if her speech and language milestones are delayed.
“Will this happen again if we have another baby?”
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- The risk of passing CMV to the baby is significantly lower when the mother already has immunity (nonprimary infection), and transmission in that situation is thought to be rare at an individual level.
- Practical measures: hand hygiene after nappies and after feeding or wiping young children’s faces; not sharing cups, utensils or toothbrushes; not putting a dummy in her own mouth; avoiding kissing young children on the mouth.
Based on: Tesini BL, et al; American Academy of Pediatrics. Care of the Infant With Congenital Cytomegalovirus Infection: Clinical Report. Pediatrics. 2026;158(4):e2026078595.
Tiny Taught · Neonatal & Paediatric Education
Teaching material for exam preparation. Doses and thresholds are for orientation only; follow local guidelines.