Cytomegalovirus Infection among Pregnant Women in Beijing: Seroepidemiological Survey and Intrauterine Transmissions

Primary cytomegalovirus (CMV) infection during pregnancy can cause congenital defects. Available data for CMV infection during pregnancy in north China are inadequate. The aim of this study was to evaluate the epidemiology of maternal CMV infection and explore the incidence of congenital infection. In this prospective study, serum CMV IgG and IgM antibodies were measured in 2,887 pregnant women using ELISA, and the IgG avidity test was performed on all IgM-positive subjects. The seroprevalence of anti-CMV IgG was 94.70%, and of anti-CMV IgM was 1.28%. CMV IgG prevalence increased significantly with age (p < 0.01). Women living in downtown areas showed higher IgG prevalence than those residing in urban areas (p = 0.023). CMV-IgM seroprevalence was highest in autumn (p = 0.021). There was no difference in IgM seroprevalence by age, socioeconomic status, geographical area, or gravida. The rate of primary CMV infection was 0.45% (13/2,887) at the first trimester. The seroconversion rate during pregnancy was 0.76% (22/2,887). One woman underwent seroconversion during pregnancy and gave birth to an infant with asymptomatic CMV infection. Congenital CMV infection was diagnosed in five of the 14 infants from 14 mothers with active infection, for a vertical transmission rate of 35.71% (5/14). Three infants were asymptomatic, whereas two infants presented symptomatic infection with hearing deficits. Although CMV IgG prevalence is relatively high in north China, significant attention to primary CMV infection during pregnancy is still needed.