[25] Cytomegalovirus Infection in Pregnancy Flashcards
What is CMV?
A member of the herpesvirus family (herpesvirus 5)
How common is CMV, in relation to other infections transmitted to the fetus during pregnancy?
It is the most common virus transmitted to the fetus during pregnancy
What proportion of women become infected with CMV during pregnancy?
Approx 1 in 100
What proportion of maternal CMV infections are vertically transmitted to the fetus?
Around 1/3
What % of fetal CMV infections will cause damage to the fetus?
5%
When is the highest risk of a fetal CMV infection causing damage to the fetus?
In the first trimester
How can maternal acquisition of CMV infection occur?
- Close contact, including household contacts and occupational exposure
- Sexual exposure
- Transfusion
- Organ transplantation
Is CMV always active?
No, it can cycle through periods where it lies dormant and then reactivates
When can CMV be passed onto other people, including the baby?
During activation
What is the most common presentation of CMV infection?
It is usually asymptomatic in immunocompetent individuals
If symptomatic, how might CMV present?
Can cause mild flu-like illness, or in some patients a mononucleosis syndrome
What can a mononucleosis syndrome-type presentation of CMV cause?
- Fever
- Splenomegaly
- Impaired liver function
What investigations are done if maternal CMV is suspected?
Viral serology for CMV specific IgM and IgG
What is a positive test for viral serology in suspected maternal CMV?
- Presence of CMV specific IgG in mother that was previously seronegative
- Presence of CMV IgM and low IgG avidity
What is meant by avidity?
The strength with which the antibody binds to the antigen