Reinfection with cytomegalovirus during pregnancy: a prospective cohort study in Canada

Background: : 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. Objective: : To identify the rate of CMV reinfection during pregnancy and its risk factors. Study Design : 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. Results: : 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. Conclusions: : 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.