SMFM Consult Series#39: Diagnosis and antenatal management of congenital cytomegalovirus infection

Diagnosis/definition: 

Primary Infection: 

• After suspicious ultrasonographic findings (e.g echogenic bowel, cerebral ventriculomegaly and calcifications, and IUGR)- testing for maternal CMV infection
• For women suspected of having primary CMV infection in pregnancy, diagnosis should be either by IgG seroconversion or with positive CMV IgM, positive IgG, and low IgG avidity (GRADE 1B)

Fetal congenital CMV infections

• Amniocentesis is the best option as a prenatal diagnostic tool to detect fetal congenital CMV infection, performed >21 weeks of gestation and >6 weeks from maternal infection (GRADE 1C)

Epidemiology/Incidence:

40,000 infants are affected each year in the US

Birth Prevalence: 

• US, 0.48-1.3%o Of seronegative women 1-4% will acquire primary infection during pregnancy
• Primary infection - 18% of their infants will symptomatic
• Of those asymptomatic primary: Up to 25% will develop sequelae by age 2
• Recurrent CMV: <1% of offspring are symptomatic at birth
• Recurrent CMV: 8% of offspring will develop sequelae by age 2 or 14% by age of 5
• Recurrent CMV: None died in the follow up period

Management: 

Screening/Work-up:

• Routine screening of all pregnant women for evidence of primary CMV Infection is not recommended (GRADE 1B)
• Based on the available literature, any antenatal therapy, either with antivirals or CMV HIG, should only be offered as part of a research protocol
• Antenatal treatment with ganciclovir or valacyclovir not recommended; and we recommend that any antenatal therapy, either with antivirals or CMV HIG, should only be offered as part of a research protocol. (Best Practice).

Prevention: Education on personal hygiene

Last Reaffirmed: Aug 1, 2022