Delayed hearing loss in congenital cytomegalovirus infection: systematic review and meta-analysis

OBJECTIVES: This study aims to evaluate the importance of universal screening for congenital Cytomegalovirus (CMV) infection in newborns using urine PCR to identify asymptomatic cases at birth, with or without early hearing impairment, and to monitor this population for the development of late-onset hearing loss. METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The literature search was conducted through four online databases ‒ PUBMED, PUBMED PMC, BVS/BIREME, and EMBASE ‒ for papers published until January 2025. The Newcastle-Ottawa Scale was used to assess the risk of bias. RESULTS: The search strategy identified 824 articles. Following the abstract screening, 22 studies were selected for full-text review, of which three met the criteria for data synthesis. All three studies were prospective, applied universal CMV screening through urine PCR, and followed patients with auditory brainstem response for at least four years. A meta-analysis was performed using a random-effects model with inverse-variance weighting and the Restricted Maximum Likelihood estimator. Among the three studies included in the assessment, 56,892 newborns were screened with urine samples. The meta-analysis found a proportion of prevalence of congenital CMV infection of 0.46%. The proportions of asymptomatic cases and late hearing impairment was 83.4% and 13.9%, respectively. Additionally, early hearing impairment was detected in 22 (12%) newborns, and one study demonstrated that 11% of asymptomatic patients developed long-term neurological sequelae in addition to hearing loss. CONCLUSION: Our meta-analysis evaluated epidemiological aspects of hearing loss associated with cCMV infection and found that a significant proportion of infants with asymptomatic infection develop late-onset hearing loss. The absence of structured screening risks missing these patients in long-term follow-up and may increase costs related to delayed diagnosis and investigation. LEVEL OF EVIDENCE: Level 2.