Transplacental Transmission of Cytomegalovirus (CMV) in Pregnant Women with Positive Anti-CMV IgG and Negative Anti-CMV IgM in Highly CMV Seropositive Region

Primary or recurrent infection of cytomegalovirus (CMV) in pregnant women may cause transplacental transmission to fetuses. We aimed to investigate the rate of transplacental CMV transmission in women with positive anti-CMV IgG and negative anti-CMV IgM and its impact on newborns. Pregnant women with positive anti-CMV IgG and negative anti-CMV IgM during the first or second trimester who delivered by Cesarean section were included. Amniotic fluid collected during the Cesarean section was tested for CMV DNA with quantitative real-time polymerase chain reaction. CMV IgG and IgM were measured with enzyme-linked immunosorbent assay. A total of 695 pregnant women were enrolled between April 2019 and February 2023. Of them, 567 (81.6%) were single pregnancies and 128 (18.4%) were twin pregnancies, and 594 (85.5%) were full-term pregnancies and 101 (14.5%) were premature pregnancies. Of the 823 newborns, 7 (0.9%) were CMV DNA positive in amniotic fluid, demonstrating the transplacental CMV transmission. One of these seven neonates was diagnosed with intrauterine growth restriction at gestation week 25⁺¹ and at birth at a gestational age of 30⁺² weeks. However, all seven children had normal hearing, vision, and neurodevelopment at the age of 18-56 months. Transplacental CMV transmission may occur in offspring of pregnant women with positive anti-CMV IgG and negative anti-CMV IgM, but the long-term sequelae appear to be minimal.