What is the treatment for Cytomegalovirus (CMV) infection in pregnancy?

Treatment for Cytomegalovirus (CMV) Infection in Pregnancy

Valganciclovir is the treatment of choice for symptomatic CMV infection during pregnancy, but should be started after the first trimester to minimize fetal exposure to systemic antiviral drugs. 1

Diagnosis and Indications for Treatment

• CMV is the most common cause of viral infection in newborn babies, affecting 1 in 200 live births in high-income countries 2
• Treatment is indicated for pregnant women with symptomatic CMV infection or when fetal ultrasound shows evidence of CMV infection 1
• Testing for CMV is usually offered only to women who develop symptoms of influenza, glandular fever, or hepatitis during pregnancy, or when routine ultrasound detects fetal anomalies suggesting CMV infection 2

Treatment Algorithm

First Trimester:

• For retinal disease in the first trimester: Use intraocular implants or intravitreous injections for local therapy to limit fetal exposure to systemic antiviral drugs 1
• Systemic antiviral therapy should be started after the first trimester 1

After First Trimester:

1. First-line treatment: Valganciclovir (based on limited data, toxicity reports, and ease of use) 1
2. Alternative options:
   • Ganciclovir (has been used safely in human pregnancy after organ transplantation) 1
   • Foscarnet (limited data; one case report of normal infant outcome in third trimester) 1
   • Valacyclovir (8g/day has shown effectiveness in preventing vertical transmission) 3

Contraindicated:

• Cidofovir is embryotoxic and teratogenic; use in pregnancy is not recommended (DIII) 1

Monitoring During Treatment

Maternal Monitoring:

• Regular clinical assessment for treatment efficacy and side effects
• Monitor for neutropenia and other hematological side effects 4

Fetal Monitoring:

• Fetal movement counting in the third trimester 1
• Periodic ultrasound monitoring after 20 weeks of gestation to detect:
  • Evidence of hydrops fetalis indicating anemia 1
  • Cerebral calcifications, abdominal/liver calcifications, microcephaly, ventriculomegaly, ascites, echogenic fetal bowel 1
• If foscarnet is used: Weekly monitoring of amniotic fluid volumes by ultrasound after 20 weeks to detect oligohydramnios 1
• Consider MRI scan of fetal brain at 28-32 weeks to assess for signs of brain damage 2

Special Considerations

• If ultrasound findings suggest in utero CMV infection, consider invasive testing (amniocentesis and fetal umbilical blood sampling) 1
• Referral to a maternal-fetal medicine specialist for evaluation, counseling, and further testing is recommended 1
• Treatment of asymptomatic maternal CMV infection during pregnancy solely to prevent infant infection is not indicated (DIII) 1
• For confirmed fetal infection, regular ultrasound scans should be offered every 2-3 weeks until birth 2

Prevention for Future Pregnancies

• Hand hygiene, especially after contact with young children 5
• Avoid sharing food, drinks, or utensils with young children 5
• Avoid undercooked meat and wash fruits and vegetables thoroughly 5

Important Caveats

• Risk of harm to the fetus is greatest following primary CMV infection in early pregnancy 2
• Approximately 11% of infected newborns are symptomatic at birth, with 30-40% at risk of developing long-term neurological sequelae 3
• All babies born to women with confirmed or suspected CMV infection should be tested within the first 21 days of life 2
• Symptomatic newborns may benefit from postnatal treatment with valganciclovir or ganciclovir 2
• There is no licensed vaccine for CMV 2

The evidence for treating CMV in pregnancy is limited, but the approach should prioritize reducing risk of fetal infection while minimizing medication exposure during critical developmental periods. The timing of infection, presence of symptoms, and evidence of fetal involvement are critical factors in treatment decisions.