Follow-Up of Hearing Impairment in Patients with Congenital CMV Infection

Background/Objectives: Congenital cytomegalovirus (cCMV) is a leading non-genetic cause of childhood sensorineural hearing loss (SNHL), characterized by heterogeneous and dynamic hearing outcomes. Hearing impairment may be present at birth or emerge later in childhood. This study aimed to characterize hearing trajectories and laterality patterns in children with cCMV, with emphasis on congenital versus delayed-onset SNHL. Methods: We conducted a retrospective study of children with confirmed cCMV who underwent longitudinal audiologic follow-up. Hearing loss was classified as congenital SNHL or delayed-onset SNHL. Better- and poorer-ear thresholds, bilateral involvement, longitudinal changes, and follow-up duration were analyzed. Results: Of 195 included children, 59 (30%) developed SNHL. Congenital SNHL was present in 34 children (17%), while delayed-onset SNHL developed in 25 of 161 children (16%) who were born with normal hearing. Of these delayed-onset cases, 20 (80%) were asymptomatic at birth, while 5 (20%) presented with non-audiological neonatal symptoms. Longitudinal observation of the delayed-onset subgroup revealed that 36 ears developed SNHL during follow-up, spanning infancy through later childhood, including one case identified in early adulthood. Better-ear thresholds were significantly better preserved in delayed-onset SNHL, while poorer-ear thresholds were comparable across groups. Children with SNHL had substantially longer follow-up duration (60 ± 44.5 months) compared with those with normal hearing (37 ± 24.4 months). Conclusions: Children with cCMV-related SNHL exhibit dynamic and asymmetric hearing trajectories with clinically relevant differences between congenital and delayed-onset SNHL. These findings underscore the necessity of a risk-stratified, long-term surveillance framework that ensures individualized long-term monitoring and promotes sustained adherence to follow-up.