Risk factors associated with late-onset hearing loss in children with congenital cytomegalovirus: a systematic review

Purpose To search for existing evidence of prognostic factors related to the development of late-onset hearing loss (LOHL) in infants with congenital cytomegalovirus (cCMV). Methods A PRISMA systematic review was performed, with the PubMed, Embase, and Web of Science databases searched from inception through to December 2023; after the application of inclusion and exclusion criteria a total of 9 papers were included in this review. PROSPERO registration number CRD42024492244. Results 9 studies encompassing a total of 292 children with late-onset hearing loss were included. A total of 12 risk factors were identified in the literature, with 6 found to be statistically significant. Late-onset hearing loss was more frequently reported in children with symptomatic than asymptomatic cCMV. Moreover, in asymptomatic cCMV cases, elevated DNAemia and salivary viral load were associated with late-onset hearing loss. Additionally, first-trimester seroconversion was identified as a risk factor for late- onset hearing loss. Further, gestational age < 37 weeks and low birth weight were found to correlate with late-onset hearing loss. Remarkably, only one study documented a relationship between late-onset hearing loss and ultrasonographic abnormalities. Conclusions Although six statistically significant risk factors have been identified, the available evidence is limited and inconsistent, preventing the establishment of reliable neonatal and maternal parameters to predict the development of LOHL in patients with CMV. There are few studies addressing this topic, and those available exhibit a low level of evidence and heterogeneous designs. More studies should be done.