Reinfection With Cytomegalovirus During Pregnancy: A Prospective Cohort Study in Canada.

Congenital cytomegalovirus infections (cCMV) are an important cause of childhood neurodevelopmental deficits. Most cCMV are the result of maternal non-primary infections during pregnancy, which can be due to reactivation or reinfection. To identify the rate of CMV reinfection during pregnancy and its risk factors. We performed a secondary analysis of CMV seropositive participants from two prospective cohort studies in Quebec, Canada. Antibody responses to four strain-specific CMV epitopes located in glycoproteins B and H were measured by enzyme-linked immunosorbent assay. CMV reinfection was defined as the appearance of an antibody response to a new epitope in the third compared to the first trimester. Risk factors for reinfection were assessed. Among 1614 participants, CMV reinfection was identified in 2.7% of participants, representing an incidence of 54.99 per 1000 person-years at risk (95% confidence interval 39.95-73.82). Age, marital status, household income, continent of birth or ethnicity were not associated with reinfection during pregnancy. The incidence of CMV reinfection during pregnancy is like what has been reported for primary infection in Quebec. A greater understanding of the patterns of reinfection is needed to inform strategies to reduce the burden of disease from cCMV.