Estimating the Prevalence of Congenital Cytomegalovirus Infection due to Primary Maternal Infection in the United States: A Probabilistic Risk Assessment Model

Background Transplacental transmission of cytomegalovirus (CMV) after primary maternal infection during the first trimester of pregnancy is associated with the most severe sequelae from congenital CMV (cCMV) infection. We estimated the prevalence of cCMV infection due to primary maternal CMV infection in the United States. Methods We built a probabilistic risk assessment model inputting 2022 national natality data, national CMV seroprevalence estimates among females 15–49 years, and published vertical transmission rates to estimate cCMV infection prevalence and distribution by maternal age group, parity, and trimester of infection during pregnancy. Results The estimated prevalence of cCMV infection due to primary maternal infection was 3.4 (95% CI: 2.0–6.0) per 1000 live births, resulting in 12,310 infants with cCMV infection in 2022. cCMV prevalence was higher among infants born to females 15–19 and 20–29 years (4.7 and 4.2 per 1000, respectively) than those born to females 30–39 and 40–49 years (2.6 per 1000, both). cCMV prevalence was higher among infants of primipara than multipara females (4.0 vs. 3.0 per 1000). Most infants with cCMV infection were born to females 20–29 years, either primipara (29%) or multipara (27%), and females 30–39 years, multipara (24%). Approximately 3160 (26%) cCMV infections resulted from first‐trimester maternal infection. Conclusion Assuming an overall cCMV prevalence of 4.4 per 1000 live births, 77% of cCMV infections in the United States may be attributable to primary maternal infections. Data on group‐specific prevalence of cCMV infection following primary maternal infection will be useful to inform preventative strategies.