CMV

Question 1

Possible indications for antenatal testing

Answer 1

1. History suggestive of CMV illness (90% are asymptomatic)
2. Abnormalities on routine antenatal US
3. Exposure to known CMV infected individual

Question 2

Congenital CMV Incidence

Answer 2

3.85/10 000 live births
Leading cause of congenital infections

Question 3

Cases of cCMV that occur in non-primary maternal infection

Answer 3

75%
In-utero transmission in non-primary infection is less likely but if infected the full range of features of cCMV is possible

Question 4

Recommendations to women to reduce CMV infection

Answer 4

1. Do not share food / utensils etc with children <3yrs
2. Do not put child’s dummy in mouth
3. Avoid kiss on lips / with saliva
4. Hand hygiene esp with children
5. Clean surfaces that come in contact with children

Question 5

Major risk factors for maternal CMV

Answer 5

Frequent prolonged contact with young children
1. Day care workers
2. Parents with child in day care

Question 6

Sensitivity and Specificity of Ultrasound in Detecting Fetal CMV

Answer 6

Sens <30-50%, Spec low

Question 7

Features of cCMV on ultrasound

Answer 7

1. Head: Microcephaly, Cerebral ventriculomegaly, intracranial calcification
2. Abdomen: Ascites, Hepatomegaly, abdominal calcification, pseudomeconium ileus, hyperechoic bowel
3. Chest: pleural or pericardial effusions
4. General: oligo / polyhydramnios, IUGR, hydrops fetalis

Question 8

Amniocentesis for CMV PCR <20 weeks

Answer 8

Sensitivity 45%, Specificity High

Question 9

Amniocentesis for CMV PCR ≥21 weeks and ≥ 6 weeks after maternal infection

Answer 9

Sensitivity 80-95%
Specificity approaches 100%
PPV approaches 100%

Question 10

Prevential of Fetal CMV Transmission

Answer 10

1. CMV Hyperimmuneglobulin (HIG) no currently routinely recommended, consider case-by-case
2. Data of valaciclovir emerging for use in first trimester

Question 11

Intervention for CMV infected fetus

Answer 11

1. Seek expert advice
2. TOP is an option (however positive PCR is not predictive of fetal damage)
3. CMV IgG can be considered (observational studies)

Question 12

Risk of fetal transmission, fetal symptoms, fetal sequelae with primary CMV

Answer 12

~30%
- symptomatic cCMV 10-15%
—–> sequelae ~50%
- asymptomatic cCMV 85-90%
—–> sequelae 10-15%

Question 13

Risk of fetal transmission, feteal symptoms, fetal sequelae with non-primary CMV (reinfection or reactivation)`

Answer 13

~1%
- symptomatic cCMV ≤1%
- asymptomatic cCMV ≥99%

—–> both have risk of sequelae ≤10%

Question 14

Overall risk of long-term sequelae in a congenitally infected child (CMV)

Answer 14

~10-20%

Question 15

Fetal transmission of CMV according to trimester

Answer 15

1. Periconception (3 months before LMP) = 5.5%
2. Periconception (4 weeks before, 6 weeks after LMP) = 21%
3. First trimester = 36.5%
4. Second trimester = 40.3%
5. Third trimester = 66%

Question 16

When is risk of severe adverse neurological outcomes greatest? (cCMV)

Answer 16

Primary infection in first trimester
(A fetus infected late in pregnancy is unlikely to have significant neurological sequelae

Question 17

Main concerns of symptomatic cCMV infection

Answer 17

1. Early mortality 5-10%
2. Neuro: microcephalic (35-50%), seizures (10%), chorioretinitis (10-20%), developmental delay (70%)
3. Sensorineural hearing loss (25-50%) - can be late onset

Question 18

Main concerns of asymptomatic cCMV infection

Answer 18

1. Senorineural hearing loss (~10%, can be late onset up to 2 years)
2. Neurodevelopmental (maybe)
3. Chorioretinitis 2%

Question 19

Period of paediatric follow-up for cCMV

Answer 19

6 years
- Audiology 6 mthly for 2 years then yearly
- Opthal yearly
- Paeds 3-6 mthly for 2 years than yearly
Normal development by 12 months is associated with higher likelihood of normal development long-term

Question 20

Neonatal examination at birth

Answer 20

≤21 days of age
- CMV PCR urine and saliva
- Newborn hearing screen
If PCR positive, ophthal review and head imaging
+/- antiviral therapy