Guideline No. 420: Cytomegalovirus Infection in Pregnancy

Objective: To provide an update on current recommendations for cytomegalovirus (CMV) infection during pregnancy. The objectives of this guideline are: To improve perinatal care providers' awareness of the consequences of maternal CMV infection for the fetus and the infant; To emphasize the importance of educating patients about how to prevent CMVacquisition during pregnancy To raise perinatal care providers' awareness of new developments in CMV screening and treatment To highlight that a substantial proportion of disability due to congenital CMV (cCMV) can be modified to some extent Target Population: Patients of child-bearing age, pregnant patients, and patients planning a pregnancy. Benefits, Harms, and Costs: The patient partners urged us to make awareness of preventive strategies a high priority, despite concern that discussing CMV with patients could cause unnecessary anxiety. CMV educational interventions have shown benefits from increased awareness of cCMV prevalence and preventive strategies among providers, patients, and families. Evidence: We searched MEDLINE, EMBASE, and CENTRAL databases for CMV in pregnancy. The search terms were developed using MeSH terms and keywords (Appendix). The results were filtered for articles published between January 2010 and October 2020 and systematic reviews, meta-analyses, clinical trials, and observational studies. The main inclusion criteria were pregnant patients and infants, as the target population, and CMV infection, as the diagnosis of interest. Recommendations are graded according to the U.S. Preventive Services Task Force grade of recommendations and level of certainty. Validation Methods: We collaborated with patient partners, including members of CMV Canada (cmvcanada.com). In formulating our recommendations, we included patients' voices to add a unique and valuable perspective, thus ensuring that our recommendations are relevant to the patient-provider partnership. Intended Audience: All perinatal health care providers. RECOMMENDATIONS (grade and level of certainty in parentheses): 1. Pregnant patients with a mononucleosis-like illness or undifferentiated hepatitis should be investigated for cytomegalovirus infection (C, low). 2. To diagnose maternal cytomegalovirus infections and to differentiate primary from non-primary infections, this guideline recommends a combination of seroconversion (defined as documentation of a change from cytomegalovirus immunoglobulin G negative to positive), cytomegalovirus immunoglobulin M, and cytomegalovirus immunoglobulin G avidity testing (B, moderate). 3. A positive immunoglobulin M result alone should be interpreted with caution when determining when a CMV infection was acquired (C, moderate). 4. Breastfeeding is considered safe in patients who had CMV infection during pregnancy (B, high). 5. If primary maternal CMV infection is diagnosed during pregnancy, or abnormal sonographic findings suggest congenital CMV infection, pregnant patients should be offered an amniocentesis for confirmation of fetal congenital infection (cCMV) at least 8 weeks after the estimated time of maternal infection (B, high). 6. This guideline recommends discussing education and hygiene measures to prevent CMV acquisition with all patients, regardless of serologic status, before conception and through pregnancy, especially early in the antepartum period (B, high). 7. CMV hyperimmune globulin should not be used to prevent congenital CMV if a primary CVM infection is diagnosed during pregnancy (B, low). 8. In the case of documented primary CMV infection in the first trimester, early treatment with valacyclovir can be considered (B, moderate). 9. For established congenital CMV infections during pregnancy, decisions concerning treatment options should be made in a shared process involving patients and experienced teams (C, low). 10. In provinces where CMV IgG avidity testing is available, screening for CMV primary infection in the first trimester ( using IgG and IgM antibodies followed by IgG avidity testing if the patient is IgM-positive) can be offered, especially in women at high risk (those who have a child under 3 years at home). CMV screening in pregnancy is not recommended in provinces where CMV IgG avidity testing is unavailable (C, low).

Automated summary

This guideline provides updated recommendations for cytomegalovirus (CMV) infection during pregnancy, emphasizing education on prevention, awareness of new developments, and the substantial impact of congenital CMV on disability.