Maturazione delle vie uditive nei bambini con infezione congenita da Citomegalovirus e ipoacusia isolata alla nascita.

Objective: To evaluate the incidence and evolution of isolated sensorineural hearing loss (SNHL) at birth in a population of newborns with congenital cytomegalovirus (cCMV) infection. Materials and methods: This prospective, single-center study was conducted at a university hospital. Fifty-five full-term newborns with asymptomatic cCMV infection, born between January 2011 and March 2020, without additional risk factors for hearing loss and who presented with bilateral “pass” otoacoustic emissions (OAE) after birth, were included. None received antiviral therapy. Hearing thresholds were repeatedly assessed by auditory evoked potentials with threshold search (ABR). Infants with SNHL were followed until possible normalization of hearing thresholds (“maturative” SNHL) or definitive diagnosis of SNHL (“true” SNHL). The worse ear was taken into account for severity classification. Results: Hearing loss was diagnosed in 18/55 (32.7%) infants at first ABR; mild in eleven cases (2/11 bilateral), moderate in four cases (3/4 bilateral) and severe in three (1/3 bilateral). One patient out of 18 developed “true” SNHL, while 17/18 spontaneously recovered a normal hearing threshold over time. Overall, the prevalence of “true” SNHL was 1.8%, 95% confidence interval (CI) = 0.06–12.30%. The first ABR was performed at a mean age of 3.35 ± 2.3 months in the 18 infants with SNHL; in the 37 newborns with normal hearing thresholds the age at first ABR was significantly different (p = 0.005 (5.8 ± 2.6 months). Conclusion: In cCMV infection, auditory neuropathy isolated at birth is mainly due to a delay in maturation of the auditory pathways that resolves spontaneously over time. This should be taken into account to avoid unnecessary and potentially harmful antiviral therapy.