Congenital cytomegalovirus infection following second and third trimester maternal infection is associated with mild childhood adverse outcome not predicted by prenatal imaging

Background: While it is clear that first trimester congenital cytomegalovirus (CMV) infection can lead to serious neonatal and childhood adverse outcome, the extent of the effect of second and third trimester congenital CMV infection is still unclear. Our aim was to study the short- and long-term outcomes following second and third trimester infection and to evaluate the contribution of prenatal imaging in a prospective cohort. Methods: We studied pregnant women with primary CMV infection in the second and third trimesters, as diagnosed by well-dated seroconversion, and proof of vertical CMV transmission. All patients underwent serial prenatal ultrasound (US) and most of them fetal magnetic resonance imaging (MRI). Follow-up information was obtained from hospital charts and by telephone interviews with parents. Results: Primary CMV infection occurred in 135 patients, 107 and 28 with second and third trimester infection, respectively. The incidence proportion of composite outcome (hearing loss or neurodevelopmental impairment) following second trimester infection was 7% (7/100, after excluding cases that were terminated) with a 3% incidence of partial unilateral sensory neural hearing loss and a 5% incidence of minor neurodevelopmental abnormalities, including slight verbal and motor delay. Following third trimester infection, there was one case of a very mild motor delay. The incidence proportion of abnormal prenatal findings on US or MRI was not significantly correlated to hearing loss or neurodevelopmental abnormalities. Conclusions: Second trimester infection is associated with a slight risk of developing mild childhood sequelae, mostly partial unilateral hearing loss, which may develop late in childhood. Prenatal imaging failed to predict the development of childhood adverse outcome.